Home

HP 6212B User's Manual

1. 5081 4969 6 9 Table 6 4 621B 14B 16B 18B Parts List cont Ref HP Qty Description Mfr Mfr Part No Desig Part No Code Front Cover with Lettering 06212 60004 06214 60004 06216 60004 06218 60004 Front Panel Assembly 06212 60002 06214 60002 06216 60002 06218 60002 Meters 1120 1247 2 25A 120V 1120 1155 2 25A 12V 1120 1137 2 25 1120 1142 2 25 60V 4040 0934 Meter Bezel 1460 0256 Meter Spring 5020 5757 A Board Blank 5020 5731 A2 Board Blank Al Board with Components 06212 60020 06214 60020 06216 60020 06218 60020 A2 Board with Components 06212 60021 06214 60021 06216 60021 06218 60021 opi did UTE 5950 1928 perating amp Service Manual 9211 5519 Corrugated Container 9220 5212 Corrugated Pad 9220 5215 6 10 Section VII CIRCUIT DIAGRAMS This section contains the circuit diagrams necessary for ing board the operation and maintenance of these power supplies b Schematic Diagram figure 7 3 which illustrates Included are the circuitry for the entire power supply Voltages are given adjacent to test points iden a Component Location Diagram Figure 7 1 and tified by encircled numbers on the schematic 7 2 show the physical location and reference and printed wiring board designator of parts mounted on the printed wir A1 MAIN BOARD
2. 4 Vcg 4 V 5 59 awl into the small hole at top of round 5 60 Before servicing a printed wiring board refer to black plastic disc located directly below Figure 5 10 Section VI of this manual contains a tabular meter face list of the instrument s replaceable parts Before replac c Rotate plastic disc clockwise cw until irig a semiconductor device refer to Table 5 6 which lists meter reads zero then rotate ccw slightly in the special characteristics of selected semiconductors order to free adjustment screw from meter If the device to be replaced is not listed in Table 5 6 the suspension If point moves repeat steps b standard manufacturers part number listed in Section and c VI is applicable 5 65 Meter Calibration 5 61 ADJUSTMENT AND 5 66 To calibrate the ammeter proceed as follows CALIBRATION a Connect test setup shown on figure 5 8 B Set CURRENT control fully clockwise Set METER SELECTION switch to mA d Turn on supply and adjust VOLTAGE con trols so that differential voltmeter indicates exactly as follows 5 62 Adjustment and calibration may be required after performance testing troubleshooting or repair and replacement Perform only those adjustments that affect the operation of the faulty circuit and no others 5 63 Meter Mechanical Zero uS mmy 62168 1 15 V 5 64 Proceed as follows to zero meter 6214B 1 00 V 6218B 1 20 a Turn off instrument after it
3. will be marked with this symbol when it is necessary for the user to refer to the instruction manual refer to Table of Contents m ale The WARNING sign denotes a hazard It WARNING calls attention to a procedure practice or the like which if not correctly per formed or adhered to could result in personal injury Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met Indicates hazardous voltages Indicate earth ground terminal The CAUTION sign denotes a hazard It calls attention to an operating pro cedure or the like which if not correct ly performed or adhered to could result in damage to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indicated con ditions are fully understood and met CAUTION DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to a Hewlett Packard Sales and Service Office for service and repair to ensure that safety features are maintained Instruments which appear damaged or defective should be made inoperative and secured against unintended operation until they can be repaired by qualified service personnel Section GENERAL INFORMATION 1 1 DESCRIPTION 1 2 This power supply is completely transistorized suitabl
4. A2 FRONT PANEL BOARD rear view Figure 7 1 Component Location Diagram Model 6212B 7 1 A1 MAIN BOARD A2 FRONT PANEL BOARD rear view Figure 7 2 Component Location Diagram Models 6214B 6216B 6218B 7 2 COMPONENT VALUE TABLE MODELS 6212B 6214B 6216B 6218B 150 V 0047 uF 10 001 10 COMPONENT 50 V 0068 10 10047 10 5 pF 65 V 0068 10 10047 F 10 5 65 V 0047 0047 10 Not Used 3 3 10 50 V 3 3 510 50 V 75 10 65 V 3k 5 5 W 1k 3 3 W 1k 5 3 W 1k 5 3 W 4 75 k 196 1 5 k 196 1 5 k 196 1 5 k 196 75 596 24 596 24 596 24 596 22k 200 5k 50 5k 50 5k 50 22k 200 5k 50 5k 50 50 5k 50 bk 50 10 100 5k 50 5k 50 5k 50 10 k 100 5k 50 1124 1 125 W 1k 596 3 W 1 1 k 5 3 W 8 2k 5 5 W 3 3 590 5 W 3 35 5 W 12k 5 5 W 7 5 5 5 W 6 8 k 596 5 W 10 k 5 5 W 590 5 W 1 5 5 W 596 5 W 820 590 3 W 820 590 3 W 2 590 2 W 2 k 5 2 W 220 5 5 W 240 5 5 W 240 5 5 W 220 5 5 W 56 k 5 5 W 30 k 5 5 W 30 k 5 5 W 30 k 5 5 W 150 5 5 W 200 5 5 W 200 5 5 W 200 5 5 W 2 k 5 5 W 820 5 5 W 820 5 5 W 820 5 5 W 680 5 5 W 390 596 5 W 1 8 k 5 5 W 1 8 k 5 5 W 1 k 5 5 W 820 5 5 W 1k 5 5 1k 590 5 W 10 5 3 W 1596 5 3
5. Winnipeg OY 1 Tel 204 786 6701 TWX 610 671 3531 NOVA SCOTIA Hewlett Packard Canada Lid Box 931 800 Windmill Road Dartmouth 838 111 Tel 902 469 7820 TWX 610 271 4482 ONTARIO Hewlett Packard Canada Ltd 1020 Morrison Dr Ottawa 8 7 Tel 613 820 6483 TWX 610 563 1636 Hewlett Packard Canada Ltd 6877 Goreway Drive Mississauga L4V 1M8 Tel 416 678 9430 TWX 610 492 4246 Hewlett Packard Canada Ltd 552 Newbold Street London N6E 255 519 686 9181 TWX 610 352 1201 QUEBEC Hewlett Packard Canada Ltd 275 Hymus Blvd Pointe Claire H9R 1G7 Tel 514 697 4232 TWX 610 422 3022 FOR CANADIAN AREAS NOT LISTED Contact Hewlett Packard Can ada Ltd in Mississauga CHILE Jorge Calcagni y Cia Ltda Arturo Burhle 065 Casilla 16475 Correo 9 Santiago Tel 220222 Telex JCALCAGNI COLOMBIA Instrumentaci n Henrik A Langebaek 8 Carrera 7 No 48 75 Apartado A reo 6287 Bogot 1 DE Tel 269 8877 Telex 44400 Instrumentaci n Langebaek amp Kier S A Carrera 63 No 49 A 31 Apartado 54098 Medellin Tel 304475 COSTA RICA Cientifica Costarricense S A Avenida 2 Calle 5 San Pedro de Montes de Oca Apartado 10159 San Jos Tel 24 38 20 24 08 19 Telex 2367 GALGUR CR CYPRUS Kypronics 19 Gregorios Xenopoulos Street P O Box 1152 Nicosia Tel 45628 29 Telex 3018 CZECHOSLOVAKIA Hewlett Pack
6. alphanumeric order by reference designators and provides the follow ing information a Reference Designators Refer to Table 6 1 b Description Refer to Table 6 2 for abbreviations Total Quantity Given only the first time the part number is listed except in instruments containing many sub modular assemblies in which case the TQ appears the first time the part number is listed in each assembly d Manufacturer s Part Number of Type e Manufacturer s Federal Supply Code Number Refer to Table 6 3 for manufacturer s name and address f Hewlett Packard Part Number g Recommended Spare Parts Quantity RS for complete maintenance of one instrument dur ing one year of isolated service h Parts not identified by a reference designator are listed at the end of Table 6 4 under Mechanical and or Miscellaneous The former consists of parts belonging to and grouped by individual assemblies the latter consists of all parts not immediately associated with an assembly 6 3 ORDERING INFORMATION 6 4 To order replacement parts address order or in quiry to your local Hewlett Packard sales office see lists at rear of this manual for addresses Specify the follow ing information for each part Model complete serial number and any Option or special modification J numbers of the instrument Hewlett Packard part number circuit reference designator and description To order a part not listed in Table 6 4 give a co
7. b If output floating connect Current b noisy programming resistor 1 uf capacitor between R11 output and ground c CR20 14 C14 leaky c Check for excessive inter d Check R42 R48 and R33 nal ripple refer to Table for noise or drift 5 2 Stage 012 013 defective d Ensure that supply is not in constant current mode under loaded conditions e Check that the test point 15 is approx 0 5 V If voltage is between 0 and 3 V supply is cons tant current operation or constant current input amplifier is defective SYMPTOM High Ripple a Check 6 2 reference voltage Table 5 2 b Noisy programming resistor R10 c CRI CR2 leaky d Check R1 R12 and C1 for noise or drift Stage 01 02 defective Poor Stability Constant Voltage Poor Tran sient Re covery Time R17 C3 defective Recovery Time Poor Load Regulation a Improper measuring tech nique refer to paragraph 5 43 b Check reference circuit volt ages Table 5 2 c C14 and CR14 leaky d Check clamp circuit Q3 CR4 VR2 e Ensure that supply is not crossing over into constant voltage operation To prevent this condition load the supp ly and turn the VOLTAGE control fully clockwise Constant Current a Improper measuring tech nique refer to paragraph 5 11 b
8. 06218 60021 5950 1928 PRR RRR MECHANICAL P C Board Assembly Main Includes Components Bushing Q7 Q7 Q5 Insulator Insulator Insulator Line Cord Line Cord Strain Relief Fuseholder Body Fuseholder Cap Fuseholder Nut Heatsink Black Knob Red Knob Binding Post Binding Post Top Cover Bottom Cover Rear Cover with Lettering 115V Rear Cover 250V Option 028 Front Cover with Lettering Front Panel Assembly Meters 2 25A 2 25A 2 25A 30V 2 25 60V Meter Bezel Meter Spring A Board Blank A2 Board Blank 120V 12V A Board with Components A2 Board with Components Operating amp Service Manual 6 8 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 Table 6 4 621 14 16 18 Parts List cont Ref HP Description Mfr Mfr Part No Desig Part No Code 9211 5519 Corrugated Container 28480 9220 5212 Corrugated Pad 28480 9220 5215 Foam Pad 28480 0757 0467 0698 5088 0698 5151 0698 5572 fxd film 121k 1 1 8W fxd film 12k 1 1 8W fxd film 29 9k 1 1 8W fxd film 60 4k 1 1 8W 24546 24546 24546 24546 4 1 8 10 1213 C4 1 8 T0 1202 F 4 1 8 0 2912 C4 1 8 T0 6042 F 0698 3440 0698 3440 0757 0269 0757 0269 fxd film 196 1 1 8W fxd film 196 1 1 8W fxd film 270 1 1 8W fxd film
9. Groenkraaglaan B 1170 Brussels Tel 02 660 5050 Telex 23 494 MALAYSIA Hewietl Packard Sales Malaysia Sdn Bhd Suite 2 21 2 22 Bangunan Angkasa Raya Jalan Ampang Kuala Lumpur Tel 483680 485653 Protel Engineering 0 Box 1917 Lot 259 Satok Road Kuching Sarawak 53544 MEXICO Hewlett Packard Mexicana S A de CV Av Perif rico Sur 6501 Mexico 23 D F Tel 905 676 4600 Telex 017 74 507 Hewlett Packard Mexicana S A de CV Rio Volga 600 Col Del Valle Monter Tel 78 32 10 MOROCCO Dolbeau 81 rue Karatchi Casablanca Tel 3041 82 Telex 23051 22822 2 rue d Agadir Boite Postal 156 Casablanca Tel 272093 5 Telex 23 739 NL MOZAMBIQUE Goncalves Ltd 162 1 Apt 14 Av D Luis Caixa Postal 107 Maputo Tel 27091 27114 Telex 6 203 NEGON Mo NETHERLANDS Hewlett Packard Benelux N V Van Heuven Goedhartlaan 121 Box 667 1181KK Amstelveen 20 47 20 21 Telex 13 216 NEW ZEALAND Hewlett Packard N Z Ltd 4 12 Cruickshank Street Kilbirnie Wellington 3 Box 9443 Courtney Place Wellington Tel 877 199 Hewlett Packard N Z Ltd Box 26 189 169 Manukau Road Epsom Auckland Tel 687 159 Analytical Medical Only Northrop Instruments amp Systems Lid Sturdee House 85 87 Ghuznee Stree Box 2406 Wellington Tel 850 091 Telex NZ 31291
10. Navigalion Road Altrincham Cheshire WA14 1NU GB England Tel 061 928 6422 Telex 668068 Hewlett Packard Ltd Lygon Court Hereward Rise Dudley Road Halesowen Wes Midlands B62 8SD GB England Tel 021 501 1221 Telex 339105 Hewlett Packard Lid Wedge House 799 London Road Thornton Heath Surrey 6XL GB England Tel 01 684 0103 8 Telex 946825 Hewlett Packard Ltd 14 Wesley St Castleford Yorks WF 10 Tel 0977 550016 TWX 5557335 Hewlett Packard Ltd Tradax House 51 Mary s Walk Maidenhead Berkshire 516 15 GB England Hewlett Packard Ltd Morley Road Staplehill Bristol 8516 407 GB England Hewlett Packard Ltd South Queensterry West Lothian EH30 9TG GB Scotland Tel 031 331 1188 Telex 72682 UNITED STATES ALABAMA 700 Century Park Suite 128 Birmingham 35226 Tel 205 822 6802 P 0 Box 4207 8290 Whitesburg Dr Huntsville 35802 Tel 205 881 4591 ARIZONA 2336 E Magnolia St Phoenix 85034 602 273 8000 2424 East Aragon Rd Tucson 85706 Tel 602 273 8000 ARKANSAS Medical Service Only P 0 Box 5646 Brady Station Little Rock 72215 501 376 1844 CALIFORNIA 1579 W Shaw Ave Fresno 93771 Tel 209 224 0582 1430 East Orangethorpe Ave Fullerton 92631 Tel 714 870 1000 5400 Wes Rosecrans Blvd 0 Box 92105 World Way Postal Center Los Angeles 90009 Tel 213 970 7500 TWX 910 325 6608 South 3939 Lankershim Boulevard North
11. 0686 5115 fxd comp 510 5 1 2W EB5115 0686 4515 comp 430 5 1 2W 4 515 0686 1515 fxd comp 150 5 1 2W EB1515 1686 2015 fxd comp 200 5 1 2W EB2015 0686 2015 fxd comp 200 5 1 2W EB2015 0686 2015 fxd comp 200 5 1 2W 2015 USED 0686 2025 0686 8215 0686 8215 0686 8215 fxd comp 2k 5 1 2W fxd comp 820 5 1 2W fxd comp R20 5 1 2W fxd comp 820 5 1 2W USED EB2025 8215 8215 EBB215 686 6815 fxd comp 680 5 1 2W LB6815 0686 5915 fxd comp 390 5 1 2W 3915 0686 1825 fxd comp 1 8k 5 1 24 1825 1686 1825 fxd comp 1 8 5 1 2W 81825 686 1025 fxd comp lk 5 1 20 1025 686 9215 fxd comp 820 5 1 2W B8215 1686 1025 fxd lk 5 1 2W EBI025 686 1025 comp lk 5 1 2W 81025 0764 0045 fxd met 22k 5 2W 28480 1811 1799 fxd ww 390 5 3W 28480 06908 5642 fxd met 3k 5 2W 27167 MM 2 2 110 3001 4 081 314 fxd ww 6 5k 5 3W 28481 0811 1718 fxd ww 10 5 29480 0811 1340 fxd ww 1 5 5M 28480 7811 1986 fxd 3 0 5 28480 0811 2499 fxd ww 6 0 5 5W 28480 USLD 0686 1015 fxd comp 100 5 1 2W NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED USED 01121 EB1015 6 5 Ref Desic
12. 115 volt power source at full load IS Model Input Current Input Power 6212B 0 29A 28W 6214B 0 29A 28W 6217B 0 25A 26W 6218B 0 25A 26W 2 17 Connections for 230 Volt Operation Figure 2 3 2 18 Normally the two primary windings of the in put transformer are connected in parallel for operation from 115 volt source To convert the power supply to operation from a 230 volt source the power transformer windings are connected in series as follows a Unplug the line cord and remove the top cover as described in Paragraph 5 3 b Remove the jumpers between taps 4 2 and 3 1 Solder a jumper between taps 3 2 on the input power transformer T1 see Figure 2 3 c Replace existing fuse with 0 5 ampere 230 volt fuse d Replace existing line cord plug with a standard 230 volt plug 2 19 Power Cable 2 20 To protect operating personnel the National Electrical Manufacturers Association NEMA recom mendis that the instrument panel and cabinet be ground ed This instrument is equipped with a three conductor power cable The third conductor is the ground conduc tor and when the cable is plugged into an appropriate receptacle the instrument is grounded The offset pin on the power cable three prong connector is the ground connection 3 18 2 1 77 TRANSFORMER PRIMARY CONNECTED FOR 230 VOLT OPERATION TRANSFORMER PRIMARY CONNECTED FOR 115 VOLT OPERATION Figure 2 3 Input Power Transformer Connections
13. 2 21 To preserve the protection feature when operating the instrument from a two contact outlet use a three prong to two prong adapter and connect the green lead on the adapter to ground 2 22 REPACKAGING FOR SHIPMENT 2 23 To insure safe shipment of the instrument it is recommended that the package designed for the instru ment be used The original packaging material is reusable If it is not available contact your local Hewlett Packard field office to obtain the materials This office will also furnish the address of the nearest service office to which the instrument can be shipped Be sure to attach a tag to the instrument which specifies the owner model number full serial number and service required or a brief description of the trouble Section OPERATING INSTRUCTIONS 3 1 TURN ON CHECKOUT PROCEDURE 3 2 The following checkout procedure describes the use of the front panel control and indicators illustrated in Figure 3 1 and ensures that the supply is operational Figure 3 1 Front Panel Controls and Indicators a Set AC toggle switch 1 upward to on posi tion indicator 2 should light b Set METER SELECTION switch 3 to VOLTS position Turn coarse 4 and fine 5 VOLTAGE trols fully ccw to ensure that output decreases to OV then turn the VOLTAGE controls fully cw to ensure that output voltage increases to the maximum rated out put voltage d Set METER SELECTION switch 3 to mA position a
14. 5 3 W 6 590 3 W 23k 190 125 W 23 k 196 125 W 45 196 125 W 45 190 125 W 500 1096 250 2096 250 20 250 2096 Tk 195 125 121 k 196 125 196 1 125 W 100 k 196 125 W 1k 1 125 W 12 k 196 125 W 196 1 125 39 k 190 125 W 1 2 k 190 125 W 29 9 k 196 25 W 270 190 125 W 33 1 125 W 1 2k 196 125 W 60 4 k 196 125 W 270 190 125 33 190 125 NOTES 9 All resistors are 1 2 5 unless otherwise specified 2 1 8 and 1 4 watt resistors are 1 100 ppm 3 220 ppm wire temperature coefficient 4 Meter switch S2 as viewed from rear Shown in voltage position 5 m m Denotes voltage feedback signal 6 Denotes current feedback signal 7 Transformer shown strapped for 115 V operation See instruction manual for 220 Vac 8 DC voltages were measured under the following conditions A Hewlett Packard voltmeter Model 3456A or 3466A or equivalent B 115 Vac input 8 Voltages referenced to S unless otherwise noted D Voltages are typical gt 10 unless otherwise noted All readings taken in constant voltage operation at maximum rated output with no load connected and current control turned fully clockwise 9 Main supply output voltages are MODEL VDC 6212B 150 6214B 22 6216B 44 6218B 78 10 Connect to proper pin number see chart below MODEL 62128 62148 62168 See 11 This circuit is used in Mod
15. C4 1 8 T0 4502 F 4 1 8 10 2701 6 4 1 8 0 1501 4 1 8 0 1501 4 1 8 0 1501 4 1 8 0 1001 4 1 8 0 1001 C4 1 8 TO 1001 F C4 1 8 T0 1001 F 4 1 8 0 1211 1025 4005051 1500 4 30D505G050BB2 Table 6 4 621B 14B 16B 18B Parts List cont Ref HP Description Desig Part No ASSIGNED Mfr Part No EB7505 EB2405 EB2405 EB2405 0686 7505 fxd comp 75 5 1 2W 0686 2405 fxd comp 24 5 1 2W 0686 2405 fxd comp 24 5 1 2W 0686 2405 fxd comp 24 5 1 2W NOT ASSIGNED 28480 28480 28480 28480 2100 0998 var dual 22k 10 2100 2526 var dual 5k 5 2100 2526 var dual 5k 5 2100 2527 var dual 10k 5 2100 2526 var dual ww 5k 5 28480 2100 2526 var dual ww 5 5 28480 2100 2527 var dual ww 10k 5 28480 2100 2527 var dual ww 10k 5 28480 NOT ASSIGNED 88206 5 L 5265 EB33G5 EB33G5 0698 5479 l fxd comp 8 2 5 1 2W 01121 0686 0555 fxd comp 1 2W 0112 0686 0555 fxd comp 1 2W 01121 0686 0555 fxd comp 55 1 2W 01121 NOT ASSIGNEI 5 3 5 0757 0280 fxd film 1k 1 1 8W 24546 C4 1 8 TU 1001 F 0757 0280 fxd film lk 1 1 8W 24546 4 1 8 10 1001 1 1757 0274 fxd film 1 21k 19 1 8W 24546 4 1 8 0 1211 0757 0274 fxd film 1 21k 1 1 8W 24546 C4 1 8 TU 1211 t 24546 C4 1 8 TO 1213 F 24546 C4 1 8 T0 1202 F 24546 4 1 8 10 2912 24546 C4 1 8 T0 6042 F 0757 0467 fxd film 121k 1 1 8W 0698 5088 fxd film 12k 1 1 8W 0698 5151 fxd film 29 9k 1 1 8W 0698 5
16. Check reference circuit voltages Table 5 2 Poor Line Regulation Constant Voltage a Improper measuring tech nique refer to paragraph 5 11 b Check reference circuit voltage Table 5 2 Poor Load Regulation Constant Voltage Poor load c Ensure that supply is not in Regulation constant current operation Constant under loaded conditions To Voltage prevent this condition en Cont d sure that output current does not exceed maximum rated output and that the current controls are fully clockwise 5 11 Table 5 4 Low Output Voltage Troubleshooting Turn the VOLTAGE control fully clockwise and disconnect the load To eliminate the constant current circuit as a cause of the malfunc tion remove CR6 cathode or anode lead Check conduction of Q7 by short ing Q5 emitter to collector Check conduction of Q5 by short ing O4 emitter to collector Check conduction of Q4 by short ing Q1 emitter to collector Table 5 5 High Output Voltage Troubleshooting Turn the VOLTAGE control to ap proximately mid range and discon nect the load If the output voltage should rise to an excessive value during the following procedures the VOLTAGE control could be damaged if it is turned full CCW Check turnoff of Q7 by disconnec ting Q5 emitter lead Check turnoff of Q5 by removing O4 collector lead increases remains low a Output remains low b Output increases re
17. MEXICO 11634 Station 11300 Lomas Blvd Albuquerque 87123 Tel 505 292 1330 TWX 910 989 1185 156 Wyatt Drive Las Cruces 88001 Tel 505 526 2484 TWX 910 9983 0550 NEW YORK 6 Automation Lane Computer Park Albany 12205 Tel 518 458 1550 TWX 710 444 4961 650 Perinton Hill Office Park Fairport 14450 Tel 716 223 9950 TWX 510 253 0092 No 1 Pennsylvania Plaza 55th Floor 34th Street amp 8th Avenue New York 10001 Tel 212 971 0800 5858 Eas Molloy Road Syracuse 13211 Tel 315 455 2486 1 Crossways Park West Woodbury 11797 Tel 516 921 0300 TWX 510 221 2183 Tel 513 671 7400 NORTH CAROLINA 5605 Roanne Way Greensboro 27409 919 852 1800 Medical Compuler Only 9920 Carver Road Cincinnati 45242 Tel 513 891 9870 16500 Sprague Road Cleveland 44130 Tel 216 243 7300 TWX 810 423 9430 962 Crupper Ave Columbus 43229 Tel 614 436 1041 330 Progress Rd Dayton 45449 513 859 8202 OKLAHOMA Box 32008 6301 Meridan Avenue Oklahoma City 73112 Tel 405 721 0200 9920 E 42nd Street Suite 121 Tulsa 74145 Tel 918 665 3300 OREGON 17890 S W Lower Boones Ferry Road Tualatin 97062 Tel 503 620 3350 PENNSYLVANIA 1021 8th Avenue King ol Prussia Industrial Park King of Prussia 19406 Tel 215 265 7000 TWX 510 660 2670 111 Zeta Drive Pittsburgh 15238 Tel 412 782 0400 SOUTH CAROLINA Box 6442 6
18. error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmen tal specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRAN TIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HP SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY ASSISTANCE Product maintenance agreements and other customer assistance agreements are available for Hewlett Packard pro ducts For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual DC POWER SUPPLY BENCH SERIES MODELS 6212B 6214B 6216B 6218B OPERATING AND SERVICE MANUAL FOR SERIALS MODEL 6212B 2240A 02411 AND ABOVE MODEL 6214B 2238A 08181 AND ABOVE MODEL 6216B 2236A 19951 AND ABOVE MODEL 6218B 2236A 09831 AND ABOVE For instrument with serial numbers above those listed a change page may be included HP Part No 5950 1928 Printed November 1982 Microfiche Part No 5950 1929 SAFETY SUMMARY The f
19. f Reading on voltmeter should not vary from reading recorded in step d by more than 8mVdc 5 17 Line Regulation Definition The change EQuT in the static value of dc output voltage resulting from a change in ac input voltage over the specified range from low line 1096 to high line 10 or from high line to low line 5 18 To test the line regulation proceed as follows a Connect variable auto transformer between input power source and power supply power input b Connect test setup shown in Figure 5 2 6 Adjust variable auto transformer for low line ac input d Set METER SELECTION switch to VOLTS position e Turn on supply and adjust VOLTAGE con trols until front panel meter indicates exactly the maximum rated output voltage f Read and record voltage indicated on voltmeter g Adjust variable auto transformer for high VAC input h Reading on voltmeter should not vary from reading recorded in step f by more than 4 mVdc 5 19 Ripple and Noise Definition The residual AC voltage which is superim posed on the DC output of a regulated power supply Ripple and noise may be specified and measured in terms of its RMS or preferably peak to peak value Ripple and noise measurement can be made at any in put AC line voltage combined with any DC output voltage and ioad current within rating 5 20 The amount of ripple and noise that is present on the power supply output is measured either in terms of t
20. has reached normal operating temperature and allow 30 e Adjust R52 until front panel ammeter in seconds for all capacitors to discharge dicates 6212B 100 mA 6214B 1 A 6216B b Insert sharp pointed object pen point or 400 mA 6218 B 200 mA 5 13 Excessive heat or pressure can lift the copper strip from the board Avoid damage by using a low power soldering iron 50 watts maximum and following these instructions Copper that lifts off the board should be cemented in place with a quick drying acetate base cement having good electrical insulating properties A break in the copper should be repaired by soldering a short length of tinned copper wire across the break Use only high quality rosin core solder when repairing etched circuit boards NEVER USE PASTE FLUX After soldering clean off any excess flux and coat the repaired area witha high quality electrical varnish or lacquer When replacing components with multiple mounting pins suchas tube sockets electrolytic capa citors and potentiometers it will be necessary to lift each pin slightly working around the components several times until it is free WARNING If the specific instructions outlinedinthe steps below regarding etched circuit boards without eyelets are not followed extensive damage to the etched circuit board will result 1 Apply heat sparingly to lead of component 2 Reheat solder vacant eyeletand quickly tobe replaced If lead of component passes insert
21. loop during the constant current operating mode is similar to that occurring during constant voltage operation except that the input to the constant current input amplifier is obtained from the current sampling resistor R33 4 17 Series Regulator 4 18 The series regulator consists of transistor stage Q7 see schematic at rear of manual The regulator serves as a series control element by altering its conduction so that the output voltage or current is kept constant The conduction of the transistor is controlled by the feedback voltage obtained from the error amplifier Diode CR7 pro tects the series transistor against reverse voltages that could develop during parallel operation if one supply is turned on before the other 4 19 Constant Voltage Input Amplifier 4 20 This circcuit consists of programming resistor R10A and B and a differential amplifier stage Q1 O2 and associated components The constant voltage in put amplifier continuously compares a fixed reference voltage with a portion of the output voltage and if a dif ference exists produces an error voltage whose amplitude and phase is proportional to the difference The error output is fed back to the series regulator through an OR gate and the driver and error amplifiers The error voltage changes the conduction of the series regulator which in turn alters the output voltage so that the dif ference between the two input voltages applied to the differential amplifier is
22. measuring device must be connected as close to the output terminals as possible when measur ing the output impedance transient response regulation or ripple of the power supply in order to achieve valid measurements A measurement made across the load in cludes the impedance of the leads to the load and such lead lengths can easily have an impedance several orders of magnitude greater than than the supply impedance thus invalidating the measurement 5 12 The monitoring device should be connected as shown in Figure 5 1 Note that the monitoring leads are connected at A not B as shown in Figure 5 1 Failure Rate 60 400 Hz 2 usec rise and fall Accuracy 1 Input resistance 20 000 Values See Paragraphs 5 16 and 5 47 RECOMMENDED MODEL HP 3456 or 3466 See Figure 5 7 Measure dc voltages Measure transient response Power supply load resistors Measure current calibrate meter Measure impedance Measure impedance to connect the measuring device at A will result in a measurement that includes the resistance of the leads bet ween the output terminals and the point of connection When measuring the constant voltage performance specifications the current controls should be set well above the maximum output current which the supply will draw since the onset of constant curent action will cause a drop in output voltage increased ripple and other per formance changes not properly ascribed to the constan
23. reduced to zero The above ac tion maintains the output voltage constant 4 21 Stage Q2 of the differential amplifier is con nected to a common S potential through impedance equalizing resistor R6 Resistor s Z1B and R2 for the 6212B are used to zero bias the input stage offsetting minor base to emitter voltage differences in Q1 and Q2 The base of Q1 is connected to a summing point at the junction of the programming resistor and the current pullout resistor R12 Instantaneous changes in output voltage result in an increase or decrease in the summing point potential Q1 is then made to conduct more or less in accordance with the summing point voltage change The resultant output error voltage is fed back to the series regulator via OR gate diode CR5 and the remaining com ponents of the feedback loop Resistor R1 in series with the base of O1 limits the current through the program ming resistor during rapid voltage turn down Diodes CR1 and CR2 form a limiting network which prevent excessive voltage excursions from over driving stage Q1 Capacitor C1 shunting the programming resistors increases the high frequency gain of the input amplifier 4 22 Constant Current Input Amplifier 4 23 This circuit is similar in appearance and opera tion to the constant voltage input circuit It consists basically of the current programming resistors R11A and B and a differential amplifier stage 012 013 and associated components 4 24 Th
24. since such a connection would give rise to a ground current path through the coax shield resulting in an erroneous measurement e The measured noise spike values must be doubled since the impedance matching resistors constitute a 2 to 1 attenuator The noise spikes observed on the oscilloscope should be less than 0 5 mV p p 50n TERMINATION POWER SUPPLY T CONNECTOR OSCILLOSCOPE CASE 2 5 0101 TveRTICAL VERTICAL INPUT T CONNEC TOR son TERMINATION Figure 5 4 CV Noise Spike Test Setup 5 31 The circuit of Figure 5 4 can also be used for the normal measurement of low frequency ripple and noise simply remove the four terminating resistors and the blocking capacitors and substitute a higher gain ver tical plug in in place of the wideband plug in required for spike measurements Notice that with these changes Figure 5 4 becomes a two cable version of Figure 5 3 5 32 Transient Recover Time Definition The time for output voltage recovery to within Y millivolts of the nominal output voltage following 2 amp step change in load current where is specified separately for each model but is generally of the same order as the load regulation specification The nominal output voltage is defined as the DC level half way between the static output voltage before and after the imposed load change and 2 is the specified load current change normally equal to the full lo
25. 270 1 1 8W NOT ASSIGNED 24546 24546 24546 24546 C4 1 8 TO 196R F C4 1 8 T0 196R F 4 1 8 10 271 4 1 8 0 271 0757 0465 0698 6076 0698 5089 0698 5089 5101 1258 5101 1565 24545 24546 24546 24546 28480 28480 fxd film 100k 1 1 84 fxd film 39k 1 1 8W fxd film 33k 1 1 8W fxd film 33k 1 1 8W switch tgl 2A 250Vac switch sl 0 5A 125Vac dc C4 1 8 T0 1005 F C4 1 8 T0 5902 F 4 1 8 10 3302 C4 1 8 T0 5302 F CHASSIS ELECTRICAL fuse 0 5 A 250 V fuse 0 25 A 250 V for use in Option 028 units only NOT ASSIGNED 2110 0012 2110 0004 28480 1854 0421 1854 0225 1854 0225 1854 0239 NPN Si NPN Si NPN Si NPN Si 9100 2608 9100 2610 9100 2609 9100 2609 transformer transformer transformer transformer MECHANICAL PARTS 0540 0168 0540 0174 1200 0181 8120 0050 0400 0015 2100 0564 2100 0565 2110 0569 Insulator Bushing Q7 Insulator Q7 Insulator Q5 Line Cord Line Cord Strain Relief Fuseholder Body Fuseholder Cap Fuseholder Nut 5020 2579 Heatsink 0570 0101 Black Knob 0570 2241 Red Knob 1510 0094 1510 0522 7101 0748 7101 0749 5081 4968 Binding Post Binding Post Top Cover Bottom Cover Rear Cover with Lettering 115V Rear Cover 230V Option 028 PRR
26. 33 IN PARTS LIST SECTION Figure 5 8 Constant Current Test Setup 5 7 5 44 Load Regulation Definition The change the static value of the dc output current resulting from a change in load resistance from short circuit to a value which yeilds max imum rated output voltage 5 45 To check the constant current load regulation proceed as follows a Connect test setup shown in Figure 5 8 b Turn VOLTAGE control s fully clockwise 6 Set METER switch to mA d Adjust CURRENT control until front panel meter reads exactly the maximum rated out put current e Read and record voltage indicated on voltmeter f Short out load resistor RI g Reading on differential voltmeter should not vary from reading recorded in step e by more than the following Model No 62128 62148 62168 62188 Variation mVdc 5 0 05 1 5 3 5 46 Line Regulation Definition The change IQUT in the static value of dc output current resulting from a change in ac input voltage over the specified range from low line usually 103 Volts to high line usually 127 Volts or from high line to low line 5 47 To check the line regulation proceed as follows a Utilize test setup shown in Figure 5 8 b Connect variable auto transformer between input power source and power supply power input Adjust auto transformer for 103 Vac input Turn VOLTAGE control s fully clockwise Set METER switch to mA Adjust CURRENT contr
27. 5 0 Box 155 Paramaribo Tel 72118 77880 SWEDEN Hewlett Packard Sverige AB Enighetsvagen 3 Fack 5 161 Bromma 20 Tel 08 730 05 50 Telex 10721 Cable MEASUREMENTS Stockholm Hewlett Packard Sverige Frotalisgatan 30 5 421 32 V stra Fr lunda Tel 031 49 09 50 Telex 10721 via Bromma office SWITZERLAND Hewlett Packard Schweiz AG Zurcherstrasse 20 0 Box 307 CH B952 Schliaren Z rich Tel 01 7305240 Telex 53933 hpag ch Cable HPAG CH Hewlett Packard Schweiz AG Chateau Bloc 19 CH 1219 Le Lignon Geneva Tel 022 96 03 22 Telex 27333 hpag ch Cable HEWPACKAG Geneva SYRIA General Electronic Inc Nuri Basha Ahnaf Ebn Kays Street P O Box 5781 Damascus Tel 33 24 87 Telex 11215 ITIKAL Cable ELECTROBOR DAMASCUS Medical only Sawah amp Co Place Azm B P 2308 Damascus Tel 16 367 19 697 14 268 Telex 11304 SATACO SY Cable SAWAH DAMASCUS Suleiman Hilal El Mawi P 0 Box 2528 Mamoun Bitar Street 56 58 Damascus 11 46 63 Telex 11270 Cable HILAL DAMASCUS TAIWAN Hewlett Packard Far East Lid Taiwan Branch Bank Tower 5th Floor 205 Tun Hau North Road Taipei Tel 02 751 0404 15 lines Hewlett Packard Far East Lid Taiwan Branch 68 2 Chung Cheng 3rd Road Kaohsiung Tel 07 242318 Kaohsiung Analytical Only San Kwang Instruments Co Ltd 20 Yung Sui Road Taipei Tel 3615446 9 4 ines Telex 22894
28. 572 fxd film 60 4k 1 1 8W 0698 5440 fxd film 196 1 1 8W 24546 4 1 8 0 196 0698 5440 fxd film 196 1 r 8W 24546 C4 1 8 TO 196R F 0757 0269 fxd film 270 1 1 8W 24546 4 1 8 10 271 0757 0269 fxd film 270 1 1 8W 24546 4 1 8 0 271 NOT ASSIGNED C4 1 8 TU 1003 F C4 1 8 T0 3902 F C4 1 8 T0 5302 F C4 1 8 T0 5502 F 0757 0465 fxd film 100k 1 1 8W 24545 0698 6076 fxd film 39k 1 5 1 8W 24546 0698 5089 fxd film 33k 1 1 8W 24546 0698 5089 fxd film 33k 1 1 8W 24546 3101 1258 switch tgl 2A 250Vac 28480 3101 1363 switch sl 0 5 125 28480 CHASSIS ELECTRICAL fuse 0 5 A 250 V NOT ASSIGNED 2110 0012 1854 0421 NPN Si 1854 0225 NPN Si 1854 0225 NPN Si 1854 0239 1 NPN Si 9100 2608 9100 2610 9100 2609 9100 2609 transformer transformer transformer transformer Ref Desig Table 6 4 621B 14B 16B 18B Parts List cont HP Qty Description Mfr Mfr Part No Part No Code 06212 60020 06214 60020 06216 60021 06218 60021 0540 0168 0540 0174 1200 0181 8120 0050 0400 0015 2100 0564 2100 0565 2110 0569 5020 2579 0570 0101 0570 2241 1510 0094 1510 0522 7101 0748 7101 0749 5081 4968 5081 4969 06212 60004 06214 60004 06216 60004 06218 60004 06212 60002 06214 60002 06216 60002 06218 60002 1120 1247 1120 1155 1120 1157 1120 1142 4040 0954 1460 0256 5020 5757 5020 5731 06212 60020 06214 60020 06216 60020 06218 60020 06212 60021 06214 60021 06216 60021
29. 8 14 CR17 18 62128 1901 0327 pwr rect 1 200 03508 14 62148 1901 0327 pwr rect 1 200V 03508 14 6216B NOT ASSIGNED 62188 1901 0327 pwr rect 1 200 03508 Al4B CR19 NOT USED CR20 1901 0053 gen prp 200mA 180V 28480 01 2 62128 1854 0823 NPN Si 28480 62148 1854 0825 NPN Si 28480 62168 1854 0823 NPN Si 28480 6218B 1854 0823 NPN Si 28480 03 4 62128 1855 0099 PNP Si 28480 62148 1853 0099 PNP Si 28480 62168 1853 0099 PNP Si 28480 62188 1853 0099 Si 28480 05 62128 1854 0825 NPN Si 28480 62140 1853 0041 PNP Si 28480 62168 1853 0041 PNP Si 28480 62188 1853 0041 PNP 51 28480 46 Q7 Q8 19 QIN 011 62128 62148 62168 62188 112 15 Table 6 4 Ref HP Qty Description Desig Part No 1854 0087 1855 0041 1855 0099 1855 0099 1855 0099 1854 0825 0812 0050 0815 0001 0815 0001 0815 0001 0757 0480 0757 0457 0757 0427 0757 0427 0757 0427 0811 2575 0811 1808 0815 0001 0811 2879 0686 1255 0686 6225 0686 7525 0686 6825 0686 2055 0686 6225 0686 6225 0686 6225 0686 1055 0686 1025 0686 1025 0686 1025 0815 0010 0815 0010 0764 0025 0764 0025 USED ASSIGNED USED ST USED Sil ww 3k 5 5W ww lk 5 3W ww lk 5 3W ww lk 5 Film 432k 1 1 8W ASSIGNED ASSIGNED ASSIGNED USED film 4 75k 1 1 8W film 1 5 1 1 8W film 1 5k 1 1 8W film 1 5k 1 1 8W USED ASSIGNED USED ASSIGN
30. 82 135066 Hewlett Packard Ges m b H Wehlistrasse 29 A 1205 Wien Tel 35 16 21 Telex 135066 BAHRAIN Medical Only Wael Pharmacy 0 Box 648 Bahrain Tel 54886 56123 Telex 8550 WAEL GJ Hamidiya Trading and Contracting 0 Box 20074 Tel 259978 259958 Telex 8895 KALDIA GJ BANGLADESH The General Electric Co of Bangladesh Lid Magnet House 72 Commercial Area Motijhell Dacca 2 Tel 252415 252419 Telex 734 BELGIUM Hewlett Packard Benelux MV Avenue du Col Vert 1 Groenkraagiaan B 1170 Brussels Tel 02 660 50 50 Telex 23 494 paloben bru BRAZIL Hewlett Packard do Brasil Le C Alameda Rio Negro 750 Alphaville 06400 Barueri SP Tel 429 3222 Hewlett Packard do Brasil L C Lida Rua Padre Chagas 32 90000 P rto Alegre RS Tel 22 2998 22 5621 Hewlett Packard do Brasil 16 6 Lida Av Epilacio Pessoa 4664 2247 1 de Janeiro RJ Tei 286 0237 Telex 021 21905 HPBR BR CANADA ALBERTA Hewlett Packard Canada Ltd 11620A 168th Street Edmonton T5M 379 Tel 403 452 3670 TWX 610 831 2431 Hewlett Packard Canada Ltd 210 7220 Fisher St S E Calgary T2H 2 8 Tel 403 253 2713 TWX 610 821 6141 BRITISH COLUMBIA Hewlett Packard Canada Lid 10691 Shellbridge Way Richmond 6 2W7 Tel 604 270 2277 TWX 610 925 5059 MANITOBA Hewlett Packard Canada Ltd 380 550 Century St St James
31. 856 1501 TWX 910 373 1267 Cable HEWPACK Palo Alto Telex 034 8300 034 8493 Hewlett Packard S A 7 rue du Bois du Lan P O Box CH 1217 Meyrin 2 Geneva Switzerland Tel 022 82 70 00 Cable HEWPACKSA Geneva Telex 2 24 86 Service Only 2 15 80 Ai MAIN BOARD Ti 0 CRIO c2 6 2 x R42 e 2 x 78 dom 90 6 Sz FINE A2 FRONT PANEL BOARD OUT 19 L 1 2 x I CI5 L al L OUT O S2 NOTE 4 A oA B3 X GB 07 06 794 Figure 7 3 Schematic Diagram PRINTED IN U S A MANUAL CHANGES DC Power Supplies Models 62128 148 168 18B Manual Part No 5950 1929 Make all corrections in the manual accordina to errata below then check the followina table for your power supply serial number and enter any listed change s in the manual SERIAL MAKE CHANGES ALL Errata On pace 1 2 under Transient Recovery Time change the end of the sentence to reaa following a change in output current equal to half the current rating of the supply On page 5 6 paragraph 5 37 letter c change the end of the sentence to read panel meter indicates exactly half the maximum rated output current Cn page 5 3 paragraph 5 16 letter f change the end of the sentence to read recorded in step d by more than 4
32. 9 663 0383 5201 Dr Rolling Meadows 60008 Tel 312 255 9800 TWX 910 687 2260 INDIANA 7301 North Shadeland Ave Indianapolis 46250 Tel 317 842 1000 810 260 1797 IOWA 2415 Heinz Road lowa City 52240 Tel 319 351 1020 KENTUCKY 10170 Linn Station Road Suite 525 Louisville 40223 Tel 502 426 0100 LOUISIANA P O Box 1449 3229 39 Williams Boulevard Kenner 70062 504 443 6201 MARYLAND 7121 Slandard Drive Parkway Industrial Center Hanover 21076 Tel 301 796 7700 TWX 710 862 1943 2 Choke Cherry Road Rockville 20850 Tel 301 948 6370 TWX 710 828 9684 MASSACHUSETTS 32 Hartwell Ave Lexington 02173 617 861 8960 TWX 710 326 6904 MICHIGAN 23855 Research Drive Farmington Hills 48024 Tel 313 476 6400 724 West Centre Ave Kalamazoo 49002 616 323 8362 MINNESOTA 2400 N Prior Ave St Paul 55113 Tel 612 636 0700 MISSISSIPPI 322 Plaza Jackson 39206 Tel 601 982 9363 MISSOURI 11131 Colorado Ave Kansas City 64137 Tel 816 763 8000 TWX 910 771 2087 1024 Executive Parkway St Louis 63141 Tel 314 878 0200 NEBRASKA Medical Only 7101 Mercy Road Suite 101 Omaha 68106 Tel 402 392 0948 NEVADA Las Vegas Tel 702 736 6610 NEW JERSEY Crystal Brook Professional Building Route 35 Eatontown 07724 Tel 201 542 1384 W 120 Century Rd Paramus 07652 Tel 201 265 5000 TWX 710 990 4951 NEW
33. 941 0 N Trenholm Road Columbia 29206 Tel 803 782 6493 TENNESSEE 8906 Kingston Pike Knoxville 37919 Tel 615 691 2371 3070 Directors Row Directors Square Memphis 38131 901 346 8370 Nashville Medical Service Only Tel 615 244 5448 TEXAS 4171 North Mesa Suite 0110 Paso 79902 915 533 3555 Box 42816 10535 Harwin St Houston 77036 713 776 6400 Lubbock Medical Service Only Tel 806 799 4472 0 Box 1270 201 E Arapaho Richardson 75081 Tel 214 231 6101 205 Billy Mitchell Road San Antonio 78226 Tel 512 434 8241 UTAH 2160 South 3270 West Street Salt Lake City 84119 Tel 801 972 4711 VIRGINIA 0 Box 9669 2914 Hungary Spring Road Richmond 23228 Tel 804 285 3431 Computer Systems Medical Only Airport Executive Center Suite 302 5700 Thurston Avenue Virginia Beach 23455 Tel 804 460 2471 WASHINGTON Bellefield Office 1203 114th Ave S E Bellevue 98004 Tel 206 454 3971 TWX 910 443 2446 Box 4010 Spokane 99202 Tel 509 535 0864 WEST VIRGINIA Medical Analytical Only 4604 Mac Corkle Ave S E Charleston 25304 Tel 304 925 0492 WISCONSIN 150 South Sunny Slope Road Brookfield 53005 Tel 414 784 8800 FOR U S AREAS NOT LISTED Contact the regional office nearest you Atlanta Georga North Holly wood California Rockville Maryland Rolling Meadows Ilinois Their complete addresses a
34. ATING INPUT GROUND CURRENT PATH IS BROKEN COMMON MODE REJECTION OF DIFFERENTIAL INPUT SCOPE IGNORES DIFFERENCE GROUND POTENTIAL OF POWER SUPPLY SCOPE SHIELDED TWO WIRE FURTHER REDUCES STRAY PICKUP ON SCOPE LEAD NOTES FOR RATING OF REFER TO R33 IN PARTS LIST SECTION VI MODEL 62128 MODEL 62148 MODEL 62168 MODEL 62188 RL 9900 IOW RL 90 10W RL 620 10W RL 2440 10W Figure 5 9 CC Ripple and Noise Test Setup 5 53 A good understanding of the principles of opera tion is a helpful aid in troubleshooting and it is recom mended that the read review Section IV of the manual before attempting to troubleshoot the unit in detail Once the principles of operation are understood refer to the overall troubleshooting procedures in Paragraph 5 56 to locate the symptom and probable cause 5 9 5 54 Once the defective component has been located by means of visual inspection or trouble analysis replace it and reconduct the performance test If a component is replaced refer to the repair and replacement and ad justment and calibration paragraphs in this section 5 55 Overall Troubleshooting Procedure 5 56 To locate the cause of trouble follow steps 1 2 and 3 in sequence Check for obvious troubles such as open fuse defective power cord input power failure or defective voltage or current meter Next remove the top and bottom covers as described in Paragrpah 5 3 inspect for open connections charred co
35. ED ASSIGNED ww 1 124k 0 1 1 8W ww 2 6k 5 3W ww lk 5 ww 4 64k 0 1 1 5W USED ASSIGNED USED comp 12k 5 1 28 comp 6 2k 5 1 2W comp 7 5k 5 1 2W comp 6 8k 5 1 2W comp 20k 5 1 2W comp 6 2k 5 1 2W comp 6 2k 5 1 2W comp 6 2k 5 1 2W comp 10 5 1 2W comp lk 5 1 24 comp lk 5 1 2W comp lk 5 1 2W ww 820 5 3W ww 820 5 met 2k 5 2W met 2k 5 2W 6 4 28480 28480 28480 28480 621 14 16 18 Parts List cont Mfr Mfr Part No Code MFACI 8 T0 4325F C4 1 8 T0 4751 F 4 1 8 0 1501 C4 1 8 T0 1501 F C4 1 8 T0 1501 F 1274 1 16 C 1124R 1350 1 16 E 4641B EB1255 6225 7525 EB6825 EB2055 EB6225 EB6225 6225 WB1035 EB1025 EBI025 EB1025 Table 6 4 6218 14B 16B 18B Parts List cont Ref HP Qty Description Mfr Mfr Part No Desig Part No Code 0686 2215 fxd comp 220 5 1 2W EB2215 0686 2415 fxd comp 240 5 1 2W EB2415 0686 2415 fxd comp 240 5 1 2W EB2415 0686 2215 comp 220 5 1 2W EB2215 0686 5655 fxd comp 56k 5 1 2W EB5655 0686 5055 fxd comp 30k 5 1 2W EB3035 0686 3035 fxd comp 30k 5 1 2W EB3035 0686 3035 fxd comp 30k 5 1 2W EB3035 0683 1035 fxd comp 10k CB1035 NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED fxd comp 3 6k 5 1W 0689 5625 GB3625 0686 4315 fxd comp 430 5 1 2W EB4315 0686 4715 fxd comp 470 5 1 2W EB4715
36. F 80 20 600V 0150 0024 Table 6 4 621 14 16 18 Parts List cont Ref HP Qty Description Mfr Mfr Part No Desig Part No Code C12 62128 ASSIGNED 6214B ASSIGNED 62168 0150 0024 cer 02uF 80 20 600V 28480 62188 ASSIGNED C13 USED 014 62128 0180 1851 elect 80uF 75 10 06001 87F742BA4 62148 0180 2258 elect 80Uf 50 10 28480 62168 0180 2258 elect 80uF 50 105 28480 62188 0180 2258 elect 80uF 450 105 28480 C15 62128 ASSIGNED 62148 0180 2141 1 fxd elect 3 3uF 10 50V 56289 1500335 905082 62168 0180 2141 fxd elect 3 3uF 10 50V 56289 150D335X9050B2 62188 0180 1836 fxd elect 5uF 75 10 65V 28480 C16 30 NOT USED C31 62128 0160 0174 fxd 0 47uF 80 20 25V 6214B NOT ASSIGNED 62168 NOT ASSIGNED 62188 NOT ASSIGNED CR1 2 1901 0033 gen prp 200mA 180 28480 CR3 1901 0461 gen prp 10V 200mA 28480 CR4 1901 0033 gen prp 200mA 180V 28480 CR5 6 1901 0461 CR7 62128 1901 0328 pwr rect 1 400 03508 Al4D 62148 1901 0327 pwr rect 1 200V 03508 14 6216B 1901 0327 pwr rect 1A 200V 03508 14 62188 1901 0327 pwr rect 1 200V 03508 14 CR8 9 NOT USED CR10 11 6212B 1901 0327 pwr rect 1 200 03508 14 62148 1901 0327 pwr rect 1 200V 03508 14 62168 1901 0327 pwr rect 1 200 03508 14 62188 1901 0327 pwr rect 1 200 03508 14 CR12 NOT USED CR13 1901 0460 stabistor 150 30V 28480 CR14 16 1901 0327 pwr rect 1 200V 0350
37. Hollywood 91604 Tel 213 877 1282 TWX 910 499 2671 3200 Hillview Av Palo Alto CA 94304 Tel 408 988 7000 646 W North Market Blvd Sacramento 95834 Tel 916 929 7222 9606 Aero Drive Box 23333 San Diego 92123 Tel 714 279 3200 363 Brookhollow Dr Santa Ana CA 92705 7 14 641 0977 3003 Scott Boulevard Santa Clara 95050 Tel 408 988 7000 TWX 910 338 0518 454 Carlton Court So San Francisco 94080 Tel 415 877 0772 Tarzana Tel 213 705 3344 COLORADO 5600 DTC Parkway Englewood 80110 Tel 303 771 3455 CONNECTICUT 47 Barnes Industrial Road Barnes Park South Wallingford 06492 Tel 203 265 7801 FLORIDA P 0 Box 24210 2727 N W 62nd Street Ft Lauderdale 33309 305 973 2600 4080 Woodcock Drive 132 Brownett Building Jacksonville 32207 904 398 0663 Box 13910 6177 Lake Ellenor Dr Orlando 32809 Tel 305 859 2900 0 Box 12826 Sune 5 Bldg 1 Office Park North Pensacola 32575 904 476 8422 110 South Hoover Blvd Suite 120 Tampa 33609 813 872 0900 GEORGIA Box 105005 450 Interstate North Parkway Atlanta 30348 404 955 1500 TWX 810 766 4890 Medical Service Only Augusta 30903 404 736 0592 Box 2103 1172 N Davis Drive Warner Robins 31098 Tel 912 922 0449 HAWAII 2875 So King Street Honolulu 96826 Tel 808 955 4455 ILLINOIS 211 Prospect Rd Bloomington 61701 Tel 30
38. L Q4 CONSTANT VOLTAGE INPUT AMPL 01 02 CI COARSE VOLTAGE RIOA FINE VOLTAGE Figure 4 1 Block Diagram 4 1 OVERALL DESCRIPTION 4 2 The major circuits of the power supply are shown on the overall block diagram Figure 4 1 4 3 The input AC line voltage is stepped down by the power transformer and applied to the rectifier and filter The rectifier filter converts the AC input to raw DC which is fed to the positive output terminal via series regulator Q7 and current sampling resistor R33 The regulator part of the feedback loop is made to alter its conduction to maintain a constant output voltage or current The 4 1 voltage developed across the current sampling resistor is the input to the constant current input amplifier The constant voltage input amplifier obtains its input by sampling the output voltage of the supply 4 4 Any changes in output voltage or current are detected in the constant voltage or constant current in put circuit amplified by the error amplifier and driver and applied to the series regulator in the correct phase and amplitude to counteract the change in output voltage or current 4 5 Two input amplifiers are included in a CV CC supply one for controlling output voltage the other for controlling output current Since the constant voltage amplifier tends to achieve zero output impedance and alters the output current whenever the load resistance changes while the constant current comp
39. Northrup instruments 8 Systems Lid House 44 Khyber Pass P 0 Box 9682 Newmarket Auckland 1 Tel 794 091 Northrup Instruments amp Systems Lid Terrace House 4 Oxford Terrace Box 8388 Christchurch Tel 64 165 NIGERIA The Electronics Insirumentations Lid N6B 770 Oyo Road Oluseun House 5402 Ibadan Tel 461577 Telex 31231 TEIL NG The Electronics insirumentations Ltd 144 Agege Motor Road Mushin Box 481 Mushin Lagos NORWAY Hewlett Packard Norge A S Ostendalen 18 0 Box 34 1345 Osteraas 02 1711 80 Telex 16621 hpnas n Hewlett Packard Norge A S Nygaardsgaten 114 P O Box 4210 5013 Nygaardsgaten Bergen Tel 05 21 97 33 PANAMA Electr nico Balboa S A Aparatado 4929 Panama 5 Calle Samuel Lewis Edificio Alfa No 2 Cludad de Panama Tel 64 2700 Telex 3483103 Curundu Cana Zone PERU Compa a Electro M dica S A Los Flamencos 145 San Isidro Casilla 1030 Lima 1 41 4325 Telex Pub Booth 25424 SISIDRO PAKISTAN Mushko amp Company Lid Oosman Chambers Abdullah Road Karachi 3 Tel 511027 512927 Telex 2894 SALES OFFICES Arranged alphabetically by country cont Mushko amp Company Ltd 10 Bazar Rd Sector G 6 4 Islamabad Tel 28264 PHILIPPINES The Online Advanced Systems Corporation Rico House Amorsolo cor Herrera Legaspi Village Box 1510 Metro Mani
40. OPERATING AND SERVICE MANUAL DC POWER SUPPLY BENCH SERIES MODELS 6212B 6214B 6216B 6218B DA U HEWLETT PACKARD CERTIFICATION Hewlett Packard Company certifies that this product met its published specifications at the time of shipment from the factory Hewlett Packard further certifies that its calibration measurements are traceable to the United States National Bureau of Standards to the extent allowed by the Bureau s calibration facility and to the calibration facilities of other International Standards Organization members WARRANTY This Hewlett Packard instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment During the warranty period Hewlett Packard Company will at its option either repair or replace products which prove to be defective For warranty service or repair this product must be returned to a service facility designated by HP Buyer shall prepay shipping charges to HP and HP shall pay shipping charges to return the product to Buyer However Buyer shall pay all shipping charges duties and taxes for products returned to HP from another country HP warrants that its software and firmware designated by HP for use with an instrument will execute its programm ing instructions when properly installed on that instrument HP does not warrant that the operation of the instru ment or software or firmware will be uninterrupted or
41. SANKWANG TANZANIA Medical Only International Ltd 0 Box 861 Dar es Salaam Tel 21251 Ext 265 Telex 41030 THAILAND UNIMESA Co Ltd Elcom Research Building 2538 Sukumvit Ave Bangchak Bangkok Tel 39 32 387 39 30 338 TRINIDAD amp TOBAGO CARTEL Caribbean Telecoms Lid Box 732 69 Frederick Street Port of Spain Tel 62 53068 TUNISIA Tunisie Electronique 31 Avenue de la Liberte Tunis Tel 280 144 Corema 1 ter Av de Carthage Tunis Tel 253 821 Telex 12319 CABAM TN TURKEY TEKNIM Company Lid Riza Sah Pehlevi Caddesi No 7 Kavaklidere Ankara Tel 275800 Telex 42155 Teknim Com Lid Barbaros 55 12 Besikyas Istanbul Tel 613 546 Telex 23540 EMA Muhendislik Sirketi Mediha Eldem Sokak 41 6 Y ksel Caddesi Anka Tel 17 56 22 Yilmaz Ozyurek Milli Mudafaa Cad 16 6 Kizilay Ankara Tel 25 03 09 17 80 26 Telex 42576 OZEK TR UNITED ARAB EMIRATES Emitac Ltd Head Office P O Box 1641 Sharjah Tel 354121 3 Telex 8136 Emitac Ltd Branch Office P O Box 2711 Abu Dhabi Tel 331370 1 UNITED KINGDOM Hewlett Packard Ltd King Street Lane Winnersh Wokingham Berkshire RG11 GB England Tel 0734 784774 Telex 84 71 78 9 Hewlett Packard Ltd Fourier House 257 263 High Street London Colney St Albans Herls GB England Tel 0727 24400 Telex 1 89527 16 Hewlett Packard Ltd Trafalgar House
42. Sensitivity 1mV full scale min Variable Voltage Transformer Range 90 130 or 200 260 volts Equipped with voltmeter accurate within 1 volt AC Voltmeter Accuracy 296 Sensitivity 1 mV full scale deflection min Oscilloscope Sensitivity 100 V cm Differential input Oscillator Range 5 Hz to 600 Hz Accuracy 296 Output 10 V rms Input impedance 10 megohms min RECOMMENDED MODEL Measure dc voltages calibra HP 3456 tion procedures Vary ac input Measure ac voltages and HP 3400 ripple HP 1800 plus 1801A and 1821A plug in s HP 200CD Display transient response waveforms Impedance checks Table 5 1 Test Equipment Required Continued REQUIRED CHARACTERISTICS MIN TYPE DC Voltmeter Repetitive Load Switch ohms Volt min time Resistive Loads Current Sam See R33 in Parts List Section VI pling Resistor Resistor 1 1 10 Watt Capacitor 500 50 W 5 8 PERFORMANCE TEST 5 9 The following test can be used as an incoming inspection check and appropriate portions of the test can be repeated either to check the operation of the instru ment after repairs or for periodic maintainence tests The tests are performed using normal single phase input power source if the correct result is not obtained for a particular check do not djust any controls proceed to troubleshooting Paragraph 5 57 5 10 Constant Voltage Tests 5 11 The
43. Table 0689 5555 0698 5269 0698 5269 0698 5091 0698 5091 0757 0954 0757 0427 0757 0427 0757 0427 0757 0280 0757 0280 0757 0280 0757 0280 0757 0274 2100 0528 2100 0439 2100 0459 2100 0459 0686 1025 1902 3185 1902 3070 1902 0761 1902 0064 1902 5070 1902 0761 1902 0049 1902 5070 1902 3002 1810 0031 0180 1841 0180 0301 0180 1836 0180 1836 1450 0510 6 4 621B 14B 16B 18B Parts List cont fxd fxd NOT fxd fxd fxd fxd fxd NOT NOT NOT trmr trmr trmr trmr NOT NOT NOT NOT fxd zene zene zene zene zene zene zene zene zene NOT NOT NOT comp 55k ASSIGNED ASSIGNED ASSIGNED USED film 25k 1 film 23k film 45k 1 film 45k 1 film 2 7k film 1 5k film 1 5k film 1 5k USED film 15 film 15 film 1 1 film 1 21k ASSIGNED ASSIGNED ASSIGNED ww l turn ww l turn ww l turn ww l turn ASSIGNED USED ASSIGNED USED comp 1 5 12 4 5 4 22 5 6 2V 5 7 5V 5 4 22V 5 6 2V 5 6 19 5 4 22 5 2 57 55 ASSIGNED ASSIGNED ASSIGNED 1 8W 1 1 8W 1 8W 1 8W 2 1 8W 1 1 8W 1 1 8W 1 8W 1 8W 1 8W 1 8W 1 8W 1 1 8W 1 2W resistance network 14 dip multiple value A2 FRONT PANEL BOARD fxd f xd fxd f xd LED elect 5uF elect 5uF elect 5uF elect 5uF 50 10 75 10 75 10 75 10 6 6 Mfr Part No C4 1 8 T0 2302 F C4 1 8 T0 2302 F C4 1 8 T0 4502 F
44. a small awl to clean inside of hole through an eyelet If hole does in the circuit E not have an CONDUCTOR board apply eyelet in SIDE heat on com sert awl or ponent side 8 a 57 drill of board If from con S ductor side lead of com ponent does of board not pass through an eyelet apply heat to conductor side of board 4 Hold part against board avoid overheating 3 Bend clean tinned lead on new part and and solder leads carefully insert Apply heat to compo through eyelets or nent leads on correct holes in board side of board as e xplained 122223 in 12222222 22222112221221722722 22212 in step 1 1272277 In the eventthat eitherthe circuit board has been damaged or the conventional method is imprac tical use method shown below Thisis especially applicablefor circuit boards without eyelets 1 Clip lead as shown below 2 Bend protrudingleads upward Bend lead of new APPLY component SOLDER around pro truding lead Apply solder using a pair of long nose pliers as a heat sink 0000000 00000000000000000000 000000 05000001 77770779772777777 78 0000000 This procedure is used in field only as an alternate means of repair It is not used within the factory Figure 5 10 Servicing Printed Wiring Boards 5 14 Section VI REPLACEABLE PARTS 6 1 INTRODUCTION 6 2 This section contains information for ordering replacement parts Table 6 4 lists parts
45. ad cur rent rating of the supply 5 33 Transient recovery time may be measured at any input line voltage combined with any output voltage and load current within rating 5 34 Reasonable care must be taken in switching the load resistance on and off A hand operated switch in series with the load is not adequeate since the resulting one shot displays are difficult to observe on most oscilloscopes and the arc energy occurring during swit ching action completely masks the display with a noise burst Transistor load switching devices are expensive if reasonably rapid load current changes are to be achieved POWER SUPPLY UNDER TEST OSCILLOSCOPE CONTACT PROTECTION RL NETWORK 50 5w 400v NOTE 3 NOTES 1 THIS DRAWING SHOWS SUGGESTED METHOD OF BUILDING A LOAD SWITCH HOWEVER OTHER METHODS COULD BE USED SUCH AS A TRANSISTOR SWITCHING NETWORK MAXIMUM LOAD RATINGS OF LOAD SWITCH ARE 5 AMPS 500V 250W NOT 2500W USE MERCURY RELAY CLARE TYPE 1002 OR TYPE 2768 LOAD SWITCH NOTE i 3 USE WIRE WOUND RESISTOR MODEL NO RL 2KQ IOW t5 200 10 5 1250 10 5 5001 10 5 Figure 5 5 Transient Recovery Time Test Setup 5 35 A mercury wetted relay as connected in the load switching circuit of Figure 5 5 should be used for loading and unloading the supply When the load switch is connected to a 60 Hz AC input the mercury wetted relay will open and close 60 time
46. ance check to ensure that the fault has been properly corrected and that no other faults exist 5 3 COVER REMOVAL AND REPLACEMENT 5 4 To remove the top and bottom covers proceed as follows a Insert a small screwdriver in each of the four notches at the front of the unit a the top and bottom Push the screwdriver under the front panel and gently pry toward the front of the unit to release the holding mechanism b Pull the front panel forward until it clears the top and bottom covers C Remove the rear cover by repeatinng step a d Pull the rear cover until it clears the top and bottom covers Then lift off the top cover and lift out the bottom cover 5 5 To replace the top and bottom cover proceed as follows a Place the unit into the bottom cover identif ed by the four protruding feet and align the heat sink into the track in the bottom cover b Place the top cover over the unit and align the track over the heat sink While holding the covers together at the rear of the unit carefully push on the rear panel d Position the front panel so that the two slot ted ears at the bottom of the panel align with the printed wiring boards e Carefully push on the front panel 5 6 TEST EQUIPMENT REQUIRED 5 7 Table 5 1 lists the test equipment required to per form the various procedures described in this Section Table 5 1 Test Equipment Required REQUIRED CHARACTERISTICS MIN Precision Voltmeter
47. and panel surfaces are free of dents and scratches and that the meter is not scratched or cracked 2 5 Electrical Check 2 6 The instrument should be checked against its electrical specifications Section V includes an in cabinet performance check to verify proper instrument operation 2 7 INSTALLATION DATA 2 8 The instrument is shipped ready for bench opera tion It is necessary only to connect the instrument to a source of power and it is ready operation 2 9 Location 2 10 This instrument is air cooled Sufficient space should be allotted so that a free flow of cooling air can reach the rear of the instrument when it is in operation It should be used in an area where the ambient temperature does not exceed 55 C 2 11 Outline Diagram 2 12 Figure 2 1 illustrates the outline shape and dimensions of Models 6211B through 6218B 2 13 Rack Mounting 2 14 This instrument may be rack mounted separately or with a maximum of two other BENCH Series supplies as shown in Figure 2 2 The units are placed in the Rack Mounting Frame The Rack Mounting Frame is then fastened to the rack frame Figure 2 2 Rack Kit with three BENCH supplies 2 15 INPUT POWER REQUIREMENTS 2 16 This power supply may be operated continuous ly from either a nominal 115 volt or 230 volt 50 400 Hz power source The unit as shipped from the factory is wired for 115 volt operation The input power required when operated from a
48. ange causes the voltage limit to be exceeded the power supply will automatically crossover to cons tant voltage output at the preset voltage limit and the output current will drop pro portionately In setting the voltage limit allowance must be made for high peak voltages which can cause unwanted crossover Refer to paragraph 3 20 3 9 CONNECTING LOADS 3 10 Each load should be connected to the power supply output terminals using separate pairs of connec ting wires This will minimize mutual coupling effects bet ween loads and will retain full advantage of the low out put impedance of the power supply Each pair of con necting wires should be as short as possible and twisted or shielded to reduce noise pickup If shield is used con nect one end to power supply ground terminal and leave the other end unconnected 3 11 If load considerations require that the output power distribution terminals be remotely located from the power supply then the power supply output terminals should be connected to the remote distribution terminals via a pair of twisted or shielded wires and each load separately connected to the remote distribution terminals 3 12 Operation of Supply Beyond Rated Output 3 13 The shaded area on the front panel meter face indicates the amount of output voltage or current that is available in excess of the normal rated output Although the supply can be operated in this shaded region without being damaged it can
49. anual 1 14 ORDERING ADDITIONAL MANUALS 1 15 One manual is shipped with each power supp ly Additional manuals may be purchased from your local Hewlett Packard field office see list at rear of this manual for addresses Specify the model number serial number prefix and HP stock number provided on the title page 1 1 STABILITY Constant Voltage Less than 0 196 5 mV total drift for 8 hours following 30 minutes warm up at constant ambient constant line voltage and constant load Constant Current Less than see table total drift for 8 hours following 30 minutes warm up at constant ambient constant line voltage and constant load 6212B 6214B 115 Vac 10 48 115 Vac 1090 48 440 Hz 0 29A 28W 440 Hz 0 3A 28W 6216B 6218B 115 Vac 10 48 115 Vac 1096 48 440 Hz 0 25A 26W 440 Hz 0 25A 26W 62128 1 3 mA OUTPUT 6214B 15 mA 62168 5 mA 6218B 2 5 mA 6214B 0 to 10 0 to 1A 6212A 0 to 100 0 to 0 1A TRANSIENT RECOVERY TIME Less than 50 for output voltage recovery in cons tant voltage operation to within 15 mV of the nominal output voltage following a change in output current equal to the current rating of the supply 6216B 6218B 0 to 25 0 to 0 to 50 0 to 0 4 0 2 OVERLOAD PROTECTION A fixed current limiting circuit pro
50. ard Obchodni zastupitelstvi v CSSR Pisemny styk Post schranka 27 CS 11801 Praha 011 CSSR Vyvojova a Provozn Zakladna Vyzkumnych Ustavu v Bechovicich CSSR 25097 Bechovice Prahy 89 93 41 Telex 12133 Institute of Medical Bionics Vyskumny Ustav Lekarskej Bioniky Jediova 6 CS 88346 Bratisiava Kramare Tel 44 551 Telex 93229 DENMARK Hewlett Packard A S Datavej 52 DK 3460 Birkerod Tel 02 81 66 40 Telex 37409 hpas dk Hewlett Packard A S Navervej 1 DK 8600 Silkeborg Tel 06 82 71 66 Telex 37409 hpas dk ECUADOR CYEDE Cia Ltda P 0 Box 6423 CCI Av Eloy Alfaro 1749 Quito Tel 450 975 243 052 Telex 2548 CYEDE ED Medical Only S A Casilla 3590 Robles 625 Quito Tel 545 250 EGYPT 1 International Engineering Associates 24 Hussein Hegazi Street Kasr el Aini Cairo Tel 23 829 Telex 93830 SAMITRO Sami Amin Trading Office 18 Abdel Aziz Gawish Abdine Cairo Tel 24932 EL SALVADOR IPESA Bulevar de los Heroes 11 48 Edificio Sarah 1148 San Salvador Tel 252787 ETHIOPIA Abdella Abdulmalik 0 Box 2635 Addis Ababa Tel 11 93 40 FINLAND Hewlett Packard Oy Revontulentie 7 SF 02100 Espoo 10 90 455 0211 Telex 121563 hewpa sf FRANCE Hewlett Packard France Zone d activites de Courtaboeut Avenue des Tropiques Boite Postale 6 91401 Orsay C dex Tel 1 907 78 25 TWX 600048F Hewlett Packard France Chemi
51. arison amplifier causes the output impedance to be infinite and changes the output vo tage in response to any load resistance change it is obvious that the two comparison amplifiers cannot operate simultaneously For any given value of load resistance the power supply must act either as a constant voltage source or as a constant current source it cannot be both transfer between these two modes is ac complished at a value of load resistance equal to the ratio of the output voltage control setting to the output cur rent control setting 4 6 Figure 4 2 shows the output characteristic of a CV CC power supply With no load attached RL oo IoUT 0 EoUT Es the front panel voltage con trol setting When a load resistance is applied to the out put terminals of the power supply the output current in creases whole the output voltage remains constant point D thus represents a typical constant voltage operating point Further decreases in load resistance are accom panied by further increases in loUT with no change in the output voltage until the output current reaches 15 a value equal to the front panel current control setting At this point the supply automatically changes its mode of oepration and becomes a constant current source still further decreases in value of load resistance are accom panied by a drop in the supply output voltage with no accompanying change in the output current value Thus point B represents a typical
52. ce portion itself see Figure 5 7 Generally any current sampling resistor should be of the low noise low temperature coefficient less than 30 ppm type and should be used at no more than 5 of its rated power so that its temperature rise will be minimized The latter reduces resistance changes due to thermal fluctuations It is recommended that for resistor the user obtain a duplicate of the sampling resistance R33 that is used in this unit for constant cur rent checks For these tests then is the difference between full load resistance and current sampling resistor Rs CURRENT SAMPLING TERMINALS EXTERNAL LOAD TO GROUNDED TERMINAL OF POWER SUPPLY SAMPLING RESISTOR LOAD TERMINALS TO UNGROUNDED TERMINAL OF POWER SUPPLY Figure 5 7 Current Sampling Resistor Connections 5 43 Rated Output and Meter Accuracy a Connect test setup shown in Figure 5 8 b Set METER SELECTION switch to mA position Turn CURRENT controls fully clockwise d Turn on supply and adjust VOLTAGE con trols until front panel meter indicates max imum rated output current e Voltmeter should read 62128 1 00 V 0 04 V 6214B 1 00 V 0 03 V 62168 1 15 V 0 035 V 6218B 1 20 V 036 V MODEL NO 6212B 9900 10 5 62148 9 10W 5596 62168 620 0 5 2441 IOW t5 POWER SUPPLY UNDER TEST PRECISION RESISTOR VOLTMETER CURRENT SAMPLING RESISTOR REFER TO R
53. constant by the voltage developed across VR8 Thus 09 provides a con stant current to zener diode R3 which regulates the 6 2 V source 4 37 Meter Circuit 4 38 This circuit provides indication of output voltage or current With METER SELECTION switch S2 set to V position the meter is in series with R54 and R52 across the output of the supply 4 39 With METER SELECTION switch S2 set to mA position the meter is connected in series with R52 and R53 across current sampling resistor R33 CURRENT ADJ potentiometer R52 is adjusted for full scale deflection with a full load connected to the output terminals Resistors R55 R14 and R57 are connected across the current sampling resistor R33 when S2 is set to V position It prevents the current sampling resistor from indicating an erroneous current by simulating the meter circuit which is connected across the current sampling resistor in the current mode Section V MAINTENANCE 5 1 INTRODUCTION 5 2 Upon receipt of the power supply the perfor mance check Paragraph 5 8 should be made This check is suitable for incoming inspection If a fault is detected in the power supply while making the performance check or during normal operation proceed to the troubleshooting procedures Paragraph 5 57 After troubleshooting and repair Paragraph 5 65 perform any necessary adjustments and calibrations Paragraph 5 67 Before returning the power supply to normal operation repeat the perform
54. constant current operating point Still further decreases in the load resistance result OPEN CIRCUIT LOAD CONSTANT VOLTAGE 8 OPERATING REGION 2 4 Rn CONSTANT CURRENT OPERATING REGION SHORT CIRCUIT LOAD Eg FRONT PANEL VOLTAGE CONTROL SETTING Ig FRONT PANEL CURRENT CONTROL SETTING Rez 55 CRITICAL OR CROSSOVER S VALUE OF LOAD RESISTANCE Figure 4 2 Operating Locus of a Cycle Power Supply in output voltage decreases with no change in output cur rent until finally with a short circuit across the output load terminals loUT s and 0 4 7 By gradually changing the load resistance from a short circuit to an open circuit the operating locus of Figure 4 2 will be traversed in the opposite direction Full protection against any overload condition is in herent in the Constant Voltage Constant Current design principle since there isn t any load condition that can cause an output which lies outside the operating locus of Figure 4 2 Whether one is primarily concerned with constant voltage or constant current operation the pro per choice of and Isinsures optimum protection for the load device as well as full protection for the power supply itself 4 8 The line connecting the origin with any operating point of the locus of Figure 4 2 has a slope which is pro portional to the value of load resistance connected to the output terminals of the supply One can defin
55. e a critical or crossover value of load resistance Es Is ad justment of the front panel voltage and current controls permits this crossover resistance Rc to be set to any desired value from 0 to If RL is greater than Rc the supply in constant voltage operation while if ML is less than Rc the supply is in constant current operation 4 9 The reference circuit provides stable reference voltages which are used by the constant voltage current input circuits for comparison purposes The meter cir cuit provides an indication of output voltage or current for both operating modes 4 10 Diode CR14 is connected across the output ter minals in reverse polarity It protects the output elec trolytic capacitor and the series regulator transistor from the effects of a reverse voltage applied across the out put terminals For example in series operation of two sup plies if the AC is removed from one supply the diode prevents damage to the unenergized supply 4 11 DETAILED CIRCUIT ANALYSIS Refer to Figures 7 1 and 7 2 Schematic Diagram 4 12 Feedback Loop 4 13 The feedback loop functions continuously to keep the output voltage constant during constant voltage operation and the output current constant during cons tant current operation For purposes of this discussion assume that the unit is in constant voltage operation and that the programming resistors R10A and B have been adjusted so that the supply is yielding
56. e constant current input amplifier continuous ly compares a fixed reference voltage with the voltage drop across current sampling resistor R33 If a difference exists The differential amplifier produces an error voltage which is proportional to this difference The remaining components in the feedback loop amplifiers and series regulator function to maintain the drop across the cur rent sampling resistor and consequently the output cur rent at a constant value R14 and R57 compensate for the current drawn by the meter when in constant cur rent mode by drawing an equivalent amount of current when output is shorted for current setting thus assuring proper current to load 4 25 Stage 013 is connected to a common 5 potential through impedance equalizing resistor R43 Resistor Z1G is used to zero bias the input stage offset ting minor base to emitter voltage differences in O12 and 013 Instantaneous changes in output current on the positive line are felt at the base of Q12 Stage O12 varies its conduction in accordance with the polarity of the change at the summing point The change in conduc tion of 012 also varies the conduction of Q13 due to the coupling effects of the common emitter resistor Z1H The error voltage is taken from the collector of Q13 and fed back to the series regulator through OR gate diode CR6 and the remaining components of the feedback loop The error voltage then varies the conduction of the regulator so that ou
57. e for either bench or relay rack operation It is a compact well regulated Constant Voltage Constant Current supply that will furnish full rated output voltage at the maximum rated output current or can be con tinuously adjusted throughout the output range The front panel CURRENT control can be used to establish the out put current limit overload or short circuit when the supp ly is used as a constant voltage source and the VOLTAGE controls can be used to establish the voltage limit ceil ing when the supply is used as a constant current source The supply will automatically crossover from constant voltage to constant current operation and vice versa if the output current or voltage exceeds these preset limits 1 3 Either the positive or negative output terminal may be grounded or the power supply can be operated floating at up to a maximum of 300 volts off ground 1 4 single meter is used to measure either output voltage or output current in volts of mA The voltage or current range is selected by the METER SELECTION switch on the front panel 1 5 SPECIFICATIONS 1 6 Detailed specifications for the power supply are given in Table 1 1 1 7 OPTIONS 1 8 Options are factory modifications of a standard instrument that are requested by the customer The following options are available for the instrument covered by this manual Where necessary detailed coverage of the options is included throughout the manual Option No De
58. el 6212B only When in use delete the lines that connect points and and point C with test point T1 SECONDARY PIN NO s ANGOLA Telectra Empresa T cnica de Equipamentos El ctricos S AR L R Barbosa Rodrigues 41 1 DT Caixa Postal 6487 Luanda Tel 35515 6 ARGENTINA Hewlett Packard Argentina S A Santa Fe 2035 Martinez 6140 Buenos Aires Tel 792 1239 798 6086 Telex 122443 AR CIGY Biotron S A CL y M Avda Paseo Colon 221 9 piso 1399 Buenos Alres Tel 30 4846 185 1 8384 34 9356 0460 455 1 Telex 33 17595 BIO AR AUSTRALIA AUSTRALIA CAPITAL TERR Hewlett Packard Australia Pty Ltd 121 Wollongong Street Fyshwick 2609 Tel 804244 Telex 62650 NEW SOUTH WALES Hewlett Packard Australia Pty Lid 31 Bridge Street Pymble 2073 Tel 4496566 Telex 21561 QUEENSLAND Hewlett Packard Australia Pty 14 5th Floor Teachers Union 495 499 Boundary Street Spring Hill 4000 Tel 2291544 SOUTH AUSTRALIA Hewlett Packard Australia Pty Ltd 153 Greenhill Road Parkside 5063 Tel 2725911 Telex 82536 VICTORIA Hewlett Packard Australia Pty 31 41 Joseph Street Blackburn 3130 Tel 89 6351 Telex 31024 MELB WESTERN AUSTRALIA Hewlett Packard Australia Ply Lid 141 Stirling Highway Nedlands 6009 Tel 3865455 Telex 93859 AUSTRIA Hewlett Packard Ges m b H Wehlistrasse 29 0 Box 7 A 1205 Vienna Tel 35 16 21 0 Telex 135
59. eldort Emanvel Leutze Sir_ 1 Seestern D 4000 D sseldorf Tel 0211 5971 1 Telex 085 86 533 hpdd d Hewlett Packard GmbH Technisches B ro Hamburg Kapstadtring 5 0 2000 Hamburg 60 Tel 040 63804 1 Telex 21 63 032 hphh d Hewlett Packard GmbH Technisches B ro Hannover Am Grossmarkt 6 D 3000 Hannover 91 Tel 0511 46 60 01 Telex 092 3259 Hewlett Packard GmbH Technisches B ro N rnberg Neumeyerstrasse 90 D 8500 N rnberg Tei 0911 52 20 83 Telex 0623 860 Hewlett Packard GmbH Technisches B ro M nchen Eschenstrasse 5 D 8021 Taufkirchen Tel 089 6117 1 Telex 0524985 Hewlett Packard GmbH Technisches Berlin Kaithstrasse 2 4 D 1000 Bertin 30 Tet 030 24 90 86 Telex 018 3405 hpbin GREECE Kostas Karayannis 8 Omirou Street Athens 133 Tei 32 30 303 32 37 731 Telex 21 59 62 RKAR GR GUAM Guam Medical Supply Inc Suite Airport P 0 Box 8947 Tamuning 96911 646 4513 GUATEMALA IPESA Avenida Reforma 3 48 Zona 9 Guatemala City Tel 316627 314786 66471 5 ext 9 Telex 4192 Teletro HONG KONG Hewlett Packard Hong Kong LId 11th Floor Four Seas Bldg 212 Nathan Rd Kowloon Tel 3 697446 5 lines Telex 36678 Hx Medical Analytical Only Schmidt amp Co Hong Kong Lid Wing On Centre 28th Floor Connaught Road Hong Kong Tel 5 455644 Telex 74766 SCHMX HX INDIA Blue Star Ltd Sahas 414 2 Vir Savarka
60. emperature remains constant during the period of measurement The supply should be put in a location immune from stray air cur rents open doors or windows air conditioning vents if possible the supply should be placed in an over which is held at a constant temperature Care must be taken that the measuring instrument has a stability over the eight hour interval which is at least an order of magnitude better than the stability specification of the power supp ly being measured Typically a supply may drift less over the eight hour measurement interval than during the 1 2 hour warm up period 5 40 To check the output stability proceed as follows a Connect the load resistance and differential voltmeter as illustrated in Figure 5 2 b Adjust front panel VOLTAGE controls until the differential voltmeter indicates the following 6212B 100 V 6214B 10 V 6216B 25V 6218B 50 V Allow 30 minutes warm up then record the differential voltmeter d After 8 hours differential voltmeter should change from indication recorded in step c by less then the following 6212B 105 mV 6214B 15 mV 6216B 30 mV 6218B 55 mV 5 41 Constant Current Tests 5 42 For output current measurements the current sampling resistor must be treated as a four terminal device In the manner of a meter shunt the load curent is fed to the extremes of the wire leading to the resistor while the sampling terminals are located as close as possi ble to the resistan
61. er minals of the power supply to the veritical input terminals of the scope When using a twisted pair care must be 5 4 taken that one of the two wires is connected to the grounded input terminal of the oscilloscope When us ing shielded two wire it is essential for the shield to be connected to ground at one end only so that no ground current will flow through this shield thus inducing a noise signal in the shielded leads POWER SUPPLY CASE OSCILLOSCOPE CASE VERTICAL A iNCORRECT METHOD GROUND CURRENT Is PRODUCES 60 CYCLE DROP IN NEGATIVE LEAD WHICH ADDS TO THE POWER SUPPLY RIPPLE DISPLAYED ON SCOPE POWER SUPPLY CASE OSCILLOSCOPE CASE B A CORRECT METHOD USING SINGLE ENDED SCOPE OUTPUT FLOATED TO BREAK GROUND CURRENT LOOP TWISTED PAIR REDUCES STRAY PICKUP ON SCOPE LEADS POWER SUPPLY CASE OSCILLOSCOPE CASE C A CORRECT METHOD USING A DIFFERENTIAL SCOPE WITH FLOATING INPUT GROUND CURRENT PATH IS BROKEN COMMON MODE REJECTION OF DIFFERENTIAL INPUT SCOPE IGNORES DIFFERENCE GROUND POTENTIAL OF POWER SUPPLY 8 SCOPE SHIELDED TWO WIRE FURTHER REDUCES STRAY PICK UP ON SCOPE LEADS Figure 5 3 Ripple and Noise Test Setup 5 26 To verify that the oscilloscope is not displaying ripple that is induced in the leads or picked up from the grounds the scope lead should be shorted to the scope lead at the power supply terminals The ple value obtained when the leads are shorted shou
62. f the other supply The constant voltage source will deliver only that fraction of its total rated output current which is necessary to fulfill the total current demand 3 2 3 19 SPECIAL OPERATING CONSIDERATIONS 3 20 Pulse Loading 3 21 The power supply will automatically cross over from constant voltage to constant current operation in response to an increase over the preset limit in the out put current Although the preset limit may be set higher than the average output current high peak currents as occur in pulse loading may exceed the preset current limit and cause crossover to occur If this crossover limiting is not desired set the preset limit for the peak requirement and not the average 3 22 Output Capacitance 3 23 An internal capacitor across the output ter minals of the power supply helps to supply high current pulses of short duration during constant voltage opera tion Any capacitance added externally will improve the pulse current capability but will decrease the safety pro vided by the current limiting circuit A high current pulse may damage load components before the average out put current is large enough to cause the current limiting circuit to operate 3 24 Reverse Current Loading 3 25 Active loads connected to the power supply may actually deliver a reverse current to the power supply dur ing a portion of its operating cycle An external source cannot be allowed to pump current into the supply
63. gapore 6th Floor Inchcape House 450 452 Alexandra Road Box 58 Alexandra Post Office Singapore 9115 Tel 631788 Telex HPSG RS 21486 SOUTH AFRICA Hewlett Packard South Africa Lid Private Bag Wendywood Sandton Transvaal 2144 Hewlett Packard Centre Daphne Street Wendywood Sandton 2144 Tel 802 5111 25 Telex 8 4782 Hewlett Packard South Africa 120 Cape Province 7450 Pine Park Centre Fores Drive Pinelands Cape Province 7405 Tel 53 7955 thru 9 Telex 57 0006 SPAIN Hewlett Packard Espa ola SA Calle Jerez 3 E Madrid 16 Tel 1 458 26 00 10 Ines Telex 23515 hpe Hewlell Packard Espa ola S A Colonia Mrasierra Edificio Juban c o Costa Brava 13 Madrid 34 Hewlett Packard Espa ola SA Milanesado 21 23 E Barcelona 17 3 203 6200 5 Ines Telex 52603 hpbe Hewlett Packard Espa ola SA Av Ram n y Cajal 1 Edificio Sevilla planta 9 E Sevilla 5 Tel 64 44 54 58 Hewlett Packard Espa ola S A Edificio Albia Il 7 E Bilbao 1 Tel 23 83 06 23 82 06 Hewlett Packard Espa ola S A C Ramon Gordillo 1 Entio E Valencia 10 Tel 96 361 13 54 361 13 58 SRI LANKA Metropolitan Agencies Ltd 209 9 Union Place Colombo 2 Tel 35947 Telex 1377METROLTD CE SUDAN Radison Trade 0 Box 921 Khartoum 44048 Telex 375 SURINAM Surtel Radio Holland N V Grote Hofsir 3
64. gberg ind Est Long Mile Road Dublin 12 Tel 14322 5 14224 Telex 30439 Medical Only Cardiac Services Ireland Ltd Kilmore Road Artane Dublin 5 Eire 01 315820 Medical Only Cardiac Services Co 954 Finaghy Rd South Belfast BT10 GB Northern Ireland Tel 0232 625566 Telex 747626 ISRAEL Electronics Engineering of Motorola Israel Lid 16 Kremenelski Street Box 25016 Tel Aviv Tel 38973 Telex 33569 34164 ITALY Hewlett Packard Italiana S p Via Di Vittorio 9 20063 Cernusco Su Naviglio Tel 2 903691 Telex 334632 Hewlett Packard Italiana S p Via Turazza 14 35100 Padova Tel 49 664888 Telex 430315 HEWPACKI Hewlett Packard Italiana S p A Armellini 10 1 00143 Roma 06 54 69 61 Telex 610514 Hewlett Packard Italiana S p Corso Giovanni Lanza 94 110133 Torino Tel 011 659308 Telex 221079 Hewlett Packard italiana S p Via Principe Nicola 43 G C 195126 Catania Tel 095 37 05 04 Telex 970291 Hewlett Packard Italiana S p Via Nuova san Rocco A Capadimonte 62 8013 Napoli Tel 081 7 10698 Hewiett Packard italiana S p A Via Martin Luther King 38 111 140132 Bologna Tel 051 402394 Telex 511630 JAPAN Yokogawa Hewlell Packard Ltd 29 21 Takaido Higashi 3 chome Suginami ku Tokyo 168 Tel 03 331 6111 Telex 232 2024 YHP Tokyo Yokogawa Hewlell Packard Ltd Chuo Bldg 4th Floor 4 20 Nishi
65. he RMS or preferably peak to peak value The peak to peak measurement is particularly important for applica tions where noise spikes could be detrimental to a sen sitive load such as logic circuitry The RMS measure ment is not an ideal representation of the noise since fairly high output noise spikes of short duration could be present in the ripple and not appreciably increase the RMS value 5 21 The technique used to measure high frequency noise or spikes on the output of a power supply is more critical than the low frequency ripple and noise measure ment technique therefore the former is discussed separately in Paragraph 5 29 5 22 Ripple and Noise Measurement Figure 5 3 shows an incorrect method of measuring p p ripple Note that a continuous ground loop exists from the third wire of the input power cord of the supply to the third wire of the input power cord of the oscilloscope via the grounded power supply case the wire between the negative output terminal of the power supply and the ver tical input of the scope and the grounded scope case Any ground current circulating in this loop as a result of the difference in potential EG between the two ground points causes an IR drop which is in series with the scope input This IR drop normally having a 60 Hz line frequen cy fundamental plus any pickup on the unshielded leads interconnecting the power supply and scope appears on the face ofthe CRT The magnitude of this resu
66. ine now represents the nominal output voltage define in the specification h Adjust the horizontal positioning control so that the trace starts at a point coincident with a major graticule division This point is then representative of time zero i Increase the sweep rate so that a single transient spike can be examined in detail Adjust the sync controls separately for the positive and negative going transients so that not only the recovery waveshape but also as much as possible of the rise time of the transient is displayed k Starting from the major graticule division representative of time zero count to the right 50 and vertically 15 mV Recovery should be within these tolerances as il lustrated in Figure 5 6 50u SECONDS 50u SECONDS t UNLOADING TRANSIENT LOADING TRANSIENT Figure 5 6 Transient Recovery Time Waveforms 5 38 Output Stability Definition The change in output voltage for the first eight hours following a 30 minute warm up period Dur ing the interval of measurement all parameters such as load resistance ambient temperature and input line voltage are held constant 5 39 This measurement is made by monitoring the output of the power supply on a differential voltmeter or digital voltmeter over the stated measurement inter val strip chart recorder can be used to provide a perma nent record A thermometer should be placed near the supply to verify that the ambient t
67. la 85 35 81 85 34 91 88 32 21 Telex 3274 ONLINE RHODESIA Field Technical Sales 45 Kelvin Road Norlh Box 3458 Salisbury Tel 705231 5 lines Telex RH 4122 POLAND Buro Informacj Technicznej Hewlett Packard UI Stawki 2 6P PLOO 950 Warszawa Tel 39 59 62 39 51 87 Telex 81 24 53 PORTUGAL Telecira Empresa T cnica de Equipamentos El ctricos Sarl Rua Rodrigo da Fonseca 103 2531 P Lisbon 1 19 68 60 72 Telex 12598 Medical Only Munainter Intercambio Mundial de Com rcio 2761 Avenida Antonio Augusto de Aguiar 138 P Lisbon Tel 19 53 21 31 7 Telex 16691 munter p PUERTO RICO Hewlett Packard Inter Americas Puerto Rico Branch Office Calle 272 203 Urb Country Club Carolina 00630 Tel 809 762 7255 Telex 345 0514 QATAR Nasser Trading 8 Contracing Box 1563 Doha Tel 22170 Telex 4439 NASSER ROMANIA Hewlett Packard Reprezentanta Balcescu 16 Bucuresti Tel 15 80 23 13 88 85 Telex 10440 SAUDI ARABIA Modern Electronic Establishment Head Office P 0 Box 1228 Baghdadiah Street Jeddah Tel 27 798 Telex 40035 Cable ELECTA JEDDAH Modern Electronic Establishment Branch Box 2728 Riyadh Tel 62596 66232 Telex 202049 Modern Electronic Establishment Branch Box 193 Ak Khobar Tel 44678 44813 Telex 670136 Cable ELECTA AL KHOBAR SINGAPORE Hewlett Packard Sin
68. ld be subtracted from the actual ripple measurement 5 27 In most cases the single ended scope method of Figure 5 3 will be adequate to eliminate non real com ponents of ripple and noise so that a satisfactory measure ment may be obtained However in more stubborn cases it may be necessary to use a differential scope with floating input as shown in Figure 5 3C If desired two single conductor shielded cables may be substituted in place of the shielded two wire cable with equal success Because of its common mode rejection a differential oscilloscope displays only the difference in signal between its two vertical input terminals thus ignoring the effects of any common mode signal introduced because of the difference in the AC potential between the power supp ly case and scope case Before using a differential input scope in this manner however it is imperative that the common mode rejection capability of the scope be verified by shorting together its two input leads at the power supply and observing the trace on the CRT If this trace is a straight line the scope is properly ignoring any common mode signal present If this trace is not a straight line then the scope is not rejecting the ground signal and must be realigned in accordance with the manufacturer s instructions until proper common mode rejection is attained 5 28 To check the ripple and noise output proceed as follows a Connect the oscilloscope or RMS voltmeter as
69. lting noise signal can easily be much greater than the true ripple developed between the plus and minus output terminals of the power supply and can completely invalidate the measurement 5 23 The same ground current and pickup problems can exist if an RMS voltmeter is substituted in place of the oscilloscope in Figure 5 3 However the oscilloscope display unlike the true RMS meter reading tells the observer immediately whether the fundamental period of the signal displayed is 8 3 milliseconds 1 120 Hz or 16 7 milliseconds 1 60 Hz Since the fundamental ripple frequency present on the output of an HP supply is 120 Hz due to full wave rectification an oscilloscope display showing a 120 Hz fundamental component is indicative of a clean measurement setup while the presence of a 60 Hz fundamental usually means that an improved setup will result in a more accurate and lower value of measure ripple 5 24 Figure 5 3 shows a correct method of measur ing the output ripple of a constant voltage power supply using a single ended scope The ground loop path is broken by floating the power supply Note that to en sure that no potential difference exists between the supply and the oscilloscope it is recommended that whenever possible they both be plugged into the same ac power buss If the grounds must be at earth ground potential 5 25 Either a twisted pair or preferably a shielded two wire cable should be used to connect the output t
70. m ponents etc If the trouble source cannot be detected by visual inspection proceed with step 2 2 In almost all cases the trouble can be caus ed by the dc bias or reference voltages thus it is a good practice to check voltages in Table 5 2 before proceeding with step 3 8 Examine Table 5 3 to determine your symp tom then check the probable cause 5 57 Regulating Loop Troubles If the voltages in Table 5 2 have been checked to eliminate the reference bias and rectifier circuits as a source of trouble the malfunction is caused by the voltage regulating loop If any component in a feedback loop is defective measurements made anywhere in the loop may appear abnormal Under these circumstances it is very difficult to separate cause from effect with the loop closed As described in Tables 5 4 and 5 5 the loop is effectively opened by checking the conduction and cutoff capabili ty of each stage as follows he Shorting the emitter to collector of a tran sistor simulates saturation or the full ON condition 2 Shorting the emitter to base or opening the collector lead of a transistor cuts it off and simulates an open circuit between emitter and collector 5 58 For low or high output voltage perform the in structions in Tables 5 4 or 5 5 respectively Although a logical first choice might be to start near the loop mid point and then perform successive subdividing test it is more useful to trace the loop from the serie
71. mVdc 8mVdc 6212B In the replaceable parts list Table 6 4 should read 6212B 14B 16B 18B Parts List 12 6 82 HP P N 1810 0031 7 6 5 4 3 2 1 8 10 11 12 13 14
72. mains low increases remains low increases a Output remains high b Output decreases a Output remains high b Output decreases 5 12 CR6 or constant cur rent amplifier defective Reconnect CR6 and proceed to Step 3 Q7 CR7 or associated parts defective Remove jumper and proceed to Step 4 Q5 CR13 R19 R23 Remove jumper and proceed to Step 5 Stage O4 defective Stage 01 02 defective Check R10 C1 for short and R12 for open Q7 CR7 or associated parts defective Replace Q5 and pro ceed to Step 3 Stage 05 defective Replace O4 collector lead and proceed to Step 4 Table 5 5 High Output Voltage Troubleshooting continued STEP ACTION response PROBABLE CAUSE Check turnoff of O4 by removing Q1 collector lead a Output remains high Output decreases a Stage O4 defective b Replace Q1 collector lead and proceed to Step 5 Remove CR3 anode or cathode Output decreases a voltage clamp circuit is defective b Reconnect CR3 and proceed to Step 6 Output remains high Connect a jumper between out and test point 1 Output remains high Output decreases a Stage Q1 Q2 defective b Remove short and check R10 for open and R12 for short Table 5 6 Selected Semiconductor Characteristics REFERENCE HP PART SUGGESTED DESIGNATOR CHARACTERISTICS NO REPLACEMENT Q7 Power NPN Silicon hfe 35 min 1854 0225 2N3055 R C A
73. mplete description of the part its function and its location Table 6 1 Reference Designators assembly miscellaneous blower fan electronic part capacitor fuse jack jumper circuit breaker diode relay device signaling inductor lamp meter 6 1 plug transistor resistor switch transformer terminal block Z thermal switch ampere alternating current assembly board bracket degree Centigrade card coefficient composition cathode ray tube center tapped direct current double pole double throw electrolytic encapsulated farad degree Farenheit fixed germanium Henry Hertz integrated circuit inside diameter incandescent kilo 103 milli 10 3 mega 10 micro 10 6 metal manufacturer Table 6 1 Reference Designators Continued vacuum tube neon bulb photocell etc zener diode socket integrated cir cuit or network Table 6 2 Description Abbreviations modular or modified mounting nano 10 9 normally closed normally open nickel plated ohm order by description outside diameter pico 10 12 printed circuit potentiometer peak to peak parts per million peak reverse voltage rectifier root mean square silicon single pole single throw small signal slow blow tantulum titanium volt variable
74. n des Mouilles 162 69130 Ecully Tel 78 33 81 25 TWX 310617F Hewlett Packard France 20 Chemin de La C pi re 31081 Toulouse Le Mirail C dex Tel 61 40 11 12 Hewlett Packard France Le Ligoures Place Rom e de Vileneuve 13100 Aix en Provence Tel 42 59 41 02 TWX 410770 Hewlett Packard France 2 Allee de la Bourgonette 35100 Rennes Tel 99 51 42 44 TWX 7409 12F Hewlett Packard France 18 rue du Canal de la Marne 67300 Schiltigheim 88 83 08 10 TWX 890141F Hewlett Packard France Immeuble p ricentre tue van Gcgh 59650 Villeneuve D Ascq Tel 20 91 4125 TWX 160124F Hewlett Packard France B timent Amp re Rue de la Commune de Paris 300 93153 Le Blanc Mesnil C dex Tel 01 931 88 50 Telex 211032 Hewlett Packard France du Pdt Kennedy 33700 Merignac Tel 56 97 01 81 Hewlett Packard France Immeuble Lorraine Boulevard de France 91035 Evry C dex Tel 077 96 60 Telex 6923 15F Hewiett Packard France 23 Rue Lothaire 57000 Metz Tel 87 65 53 50 GERMAN FEDERAL REPUBLIC Hewlett Packard GmbH Vertnebszentrale Frankfurt Berner Strasse 117 Postfach 560 140 0 6000 Frankfurt 56 Tel 06011 50041 Telex 04 13249 d Hewlett Packard GmbH Technisches B ro B blingen Herrenberger Strasse 110 0 7030 B blingen W rttemberg Tel 07031 667 1 Telex 07265739 bon Hewlett Packard GmbH Technisches B ro DUss
75. nakajima 5 chome Yodogawa ku Osaka shi Osaka 532 06 304 602 1 Telex 523 3624 Yokogawa Hewiett Packard Sunitomo Seime Nagaya Bldg 11 2 Shimosasajima cho Nakamura ku Nagoya 450 Tel 052 571 5171 Yokogawa Hewlett Packard Lid Tanigawa Building 2 24 1 Tsuruya cho Kanagawa ku Yokohama 221 Tel 045 312 1252 Telex 382 3204 YHP YOK Yokogawa Hewlell Packard ud Mito Mitsui Building 105 1 San no maru Mito 310 Tel 0292 25 7470 Yokogawa Hewlell Packard Lid Inoue Building 1348 3 Asahi cho 1 chome Atsugi Kanagawa 243 Tel 0462 24 0452 Yokogawa Hewlel Packard Ltd Kumagaya Asahi Hachijuni Building 4th Floor 3 4 Tsukuba Kumagaya Sailama 360 Tel 0485 24 6563 JORDAN Mouasher Cousins Co P O Box 1387 Amman Tel 24907 39907 Telex SABCO JO 1456 KENYA ADCOM Lid Inc 0 Box 30070 Nairobi Tel 331955 Telex 22639 Medical Only International Aeradio Ltd Box 19012 Nairobi Airport Nairobi Tel 336055 56 Telex 22201 22301 Medical Only International Aeradio Lid 0 Box 95221 Mombasa KOREA Samsung Electronics Co Ltd 4759 Shingil 6 Dong Yeong Deung POU Seoul Tel 833 4122 4121 Telex SAMSAN 27364 KUWAIT Al Khaldiya Trading 8 Contracting Box 830 Satat Kuwait Tel 42 4910 41 1726 Telex 2481 Areeg kt LUXEMBURG Hewlett Packard Beneluz SAJN V Avenue du Col Verl 1
76. nd short circuit and out put terminals e Turn coarse 6 and fine 7 CURRENT con trols fully ccw and then fully cw to ensure that the output current reaches zero and maximum rated output TA Remove short and connect load to output terminals 3 3 OPERATION 3 4 The power supply can be operated as a single unit normal operation in parallel or in series The output of the supply can be floated up to 300 volts off ground 3 1 3 5 Constant Voltage 3 6 To select a constant voltage output proceed as follows a Turn on power supply and adjust VOLTAGE controls for desired output voltage output terminals open b Short output terminals and adjust CURRENT controls for maximum output current allowable current limit as determined by load conditions If a load change causes the current limit to be exceeded the power supply will automatically crossover to cons tant current output at the present current limit and the output voltage will drop pro portionately In setting the current limit allowance must be made for high peak cur rent which can cause unwanted cross over Refer to paragraph 3 20 3 7 CONSTANT CURRENT 3 8 To select a constant current output proceed as follows a Short output terminals and adjust CURRENT controls for desired output current b Open output terminals and adjust VOLTAGE controls for maximum output voltage allowable voltage limit as determined by load conditions If a load ch
77. not be guaranteed to meet all of its performance specifications However if the line voltage is maintained above 115 Vac the supply will pro bably operate within its specifications 3 14 OPTIONAL OPERATING MODES 3 15 Series Operation 3 16 Normal Series Connections Two or more power supplies can be operated in series to obtain a higher voltage than that available from a single supply When this connection is used the output voltage is the sum of the voltages of the individual supplies Each of the individual supplies must be adjusted in order to ob tain the total output voltage The power supply contains a protective diode connected internally across the out put which protects the supply if one power supply is turn ed off while its series partner s is on 3 17 Parallel Operation 3 18 Two or more power supplies can be connected in parallel to obtain a total output current greater than that available from one power supply The total output current is the sum of the output currents of the individual power supplies The output of each power supply can be set separately The output voltage controls of one power supply should be set to the desired output voltage the other power supply should be set for a slightly larger output voltage The supply set to the lower output voltage will act as a constant voltage source the supply set to the higher output will act as a current limit source drop ping its output voltage until it equals that o
78. ntrol until front panel meter reads exactly the maximum rated out put current e The peak to peak ripple and noise indication should be less than 6212B 6214B 6216B 6218B 5 0 mV 0 5 mV 1 5 mV 3 0 mV 5 51 TROUBLESHOOTING 5 52 Before attempting to troubleshoot this instru ment ensure that the fault is with the instrument and not with an associated circuit The performance test Paragraph 5 8 enables this to be determined without having to remove the instrument from the cabinet NOTE The normal voltages shown on the schematic diagram at the rear of the manual are positioned adjacent ot the ap plicable test point identified by encircl ed numbers on the component location diagram and schematic diagram Figures 7 1 and 7 2 POWER SUPPLY CASE OSCILLOSCOPE CASE GNO A INCORRECT METHOD GROUND CURRENT PRODUCES 60 CYCLE DROP IN NEGATIVE LEAD WHICH ADDS TO THE POWER SUPPLY RIPPLE DISPLAYED ON SCOPE POWER SUPPLY CASE OSCILLOSCOPE CASE GND PATH TWISTED PAIR X LENGTH OF LEAD BETWEEN Ry AND OUTPUT TERMINAL OF POWER SUPPLY MUST BE HELD TO ABSOLUTE MINIMUM B A CORRECT METHOD USING A SINGLE ENDED SCOPE OUTPUT FLOATED TO BREAK GROUND CURRENT LOOP TWISTED PAIR REDUCES STRAY PICKUP ON SCOPE LEADS POWER SUPPLY CASE OSCILLOSCOPE CASE TWO WIRE LENGTH OF LEAD BETWEEN Ry AND GROUNDED OUTPUT TERMINAL OF POWER SUPPLY MUST BE HELD TO ABSOLUTE MINIMUM C A CORRECT METHOD USING A DIFFERENTIAL SCOPE WITH FLO
79. ollowing general safety precautions must be observed during all phases of operation service and repair of this instru ment Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Hewlett Packard Company assumes no liability for the customer s failure to comply with these requirements BEFORE APPLYING POWER Verify that the product is set to match the available line voltage and the correct fuse is installed GROUND THE INSTRUMENT This product is a Safety Class 1 instrument provided with a protective earth terminal To minimize shock hazard the in strument chassis and cabinet must be connected to an elec trical ground The instrument must be connected to the ac power supply mains through a three conductor power cable with the third wire firmly connected to an electrical ground safety ground at the power outlet For instruments designed to be hard wired to the ac power lines supply mains connect the protective earth terminal to a protective conductor before any other connection is made Any interruption of the protec tive grounding conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury If the instrument is to be energized via an external autotransformer for voltage reduction be certain that the autotransformer common terminal is c
80. ols until front panel meter reads exactly the maximum rated out put current g Read and reccord voltage indicated on voltmeter h Adjust variable auto transformer for 127 Vac input i Reading on voltmeter should not vary from reading recorded in step g by more than the following Model No 6212B 6214B 6216B 6218B Variation mVdc 5 0 0 75 1 5 3 0 5 48 Ripple and Noise Definition The residual ac current which is superim posed on the dc output current of a regulated supply Ripple and noise may be specified and measured in terms of its RMS or preferably peak to peak value 5 49 Most of the instructions pertaining to the ground loop and pickup problems associated with constant voltage ripple and noise measurement also apply to the measurement of constant current ripple and noise Figure 5 9 illustrates the most important precautions to be observed when measuring the ripple and noise of a con stant current supply The presence of a 120 cycle waveform on the oscilloscope is normally indicative of a correct measurement method A waveshape having 60 Hz as its fundamental component is typically associated with an incorrect measurement setup 5 50 Ripple Noise Measurement check the peak to peak ripple and noise proceed as follows a Connect the oscilloscope as shown in Figures 5 9B or 5 9C b Rotate the VOLTAGE control fully cw 6 Set METER switch to mA and turn on supply d Adjust CURRENT co
81. onnected to the neutral earthed pole of the ac power lines supply mains INPUT POWER MUST BE SWITCH CONNECTED For instruments without a built in line switch the input power lines must contain a switch or another adequate means for disconnecting the instrument from the ac power lines supply mains DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gases or fumes KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified service personnel Do not replace com ponents with power cable connected Under certain condi tions dangerous voltages may exist even with the power cable removed To avoid injuries always disconnect power discharge circuits and remove external voltage sources before touching components DO NOT SERVICE OR ADJUST ALONE Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT EXCEED INPUT RATINGS This instrument may be equipped with a line filter to reduce electromagnetic interference and must be connected to a pro perly grounded receptacle to minimize electric shock hazard Operation at line voltages or frequencies in excess of those stated on the data plate may cause leakage currents in excess of 5 0 mA peak SAFETY SYMBOLS Instruction manual symbol the product
82. r Marg Prabhadevi Bombay 400 025 Tel 45 78 87 Telex 011 4093 Blue Star Ltd Band Box House Prabhadevi Bombay 400 025 45 73 01 Telex 011 3751 Blue Star Ltd Bhavdeep Stadium Road Ahmedabad 380 014 Tel 43922 Telex 012 234 Blue Star Lid 7 Hare Street Calcutta 700 001 Tel 23 0131 Telex 021 7655 Blue Star Ltd Bhandari House 91 Nehru Place New Delhi 110 024 Tel 682547 Telex 031 2463 Blue Star Lid T C 7 603 Pootnima Maruthankuzhi Trivandrum 695 013 Tel 65799 Telex 0884 259 Blue Star Ltd 11 Magarath Road Bangalore 560 025 Tei 55668 Telex 0845 430 Blue Star Lid Meeaksh Mandiram XXXXV 1379 2 Mahatma Gandhi Rd Cochin 682 016 Tel 32069 Telex 085 514 Blue Star Lid 1 1 117 1 Sarojini Devi Road Secunderabad 500 033 Tei 70126 Telex 0155 459 Blue Star Ltd 133 Kodambakkam High Road Madras 600 034 Tel 82057 Telex 041 379 ICELAND Medical Only Elding Trading Company Inc Hainarnvoli Tryggvag tu P O Box 895 IS Reykjavik 1 58 20 1 63 03 INDONESIA BERCA Indonesia P T Box 496 MI Jin Abdul Muis 62 Jakarta Tel 349255 349886 Telex 46748 BERSIL SALES OFFICES Arranged alphabetically by country BERCA Indonesia Box 174 Sby 23 Jin Jimerto Surabaya 42027 IRELAND Hewlett Packard Lid Kestrel House Clanwiliam Place Lower Mount Street Dublin 2 Eire Hewlett Packard Lid 2C Avon
83. re listed above USSR Hewlett Packard Representative Office USSR Pokrovsky Boulevard 4 17 kw 12 Moscow 101000 Tel 294 20 24 Telex 7825 hewpak su YUGOSLAVIA Iskra Commerce n sol o Zastopstvo Obilicev Venac 26 YU 11000 Beograd Tel 636 955 Telex 11530 Iskra Commerce n sol 0 Zastopstvo Hewlett Packard Miklosiceva 3B VII YU 61000 Ljubljana Tel 321 674 315 879 Telex 31583 URUGUAY Pablo Ferrando S C el Avenida llalia 2877 Casilla de Correo 370 Montevideo Tel 40 3102 Telex 702 Public Booth Para Pablo Ferrando VENEZUELA Hewlett Packard de Venezuela CA Box 50933 Caracas 105 Los Ruices Norte 3a Transversal Edificio Segre Caracas 107 Tel 239 4133 20 lines Telex 25146 HEWPACK ZAMBIA R J Tilbury Zambia Ltd P O Box 2792 Lusake 73793 MEDITERRANEAN AND MIDDLE EAST COUNTRIES NOT SHOWN PLEASE CONTACT Hewlett Packard S A Mediterranean and Middle East Operations 35 Kolokotroni Street Platia Kefallariou GR Kifissia Athens Greece Tel 8080359 429 Telex 21 6588 Cable HEWPACKSA Athens SOCIALIST COUNTRIES NOT SHOWN PLEASE CONTACT Hewlett Packard Ges m b H Handelskai 52 Box 7 A 1205 Vienna Austria Tel 0222 35 16 21 10 27 Cable HEWPAK Vienna Telex 75923 hewpak OTHER AREAS NOT LISTED CONTACT Hewlett Packard Intercontinental 3495 Deer Creek Road Palo Alto California 94304 Tel 415
84. rs amplify the error signal from the constant voltage input circuit to a level sufficient to drive the series regulator transistor Amplifier 04 also receives a current limiting input if CR6 the cur rent limiting diode becomes forward biased 4 32 Stage 04 contains a feedback equalizer network C3 and R17 which provides for high frequency roll off in the loop gain in order to stabilize the feedback loop 4 4 4 33 Reference Regulator Circuit 4 34 The reference regulator circuit is a separate power supply similar to the main supply It provides stable reference voltages which are used throughout the unit The reference voltages are all derived from smoothed dc obtained from the full wave rectifier CR10 and CR11 and filter capacitor C5 The 6 2 V and 12 4 V reference voltages are derived from VR1 which is a se cond dc source regulating at 12 4 Vdc Current for VR1 is supplied by the side of C5 and flows through the base emitter junction of 07 R20 and back to the positive side of C5 4 35 The base emitter junction of Q11 is held cons tant by 6 2 V zener diode VR7 which regulates line voltage changes that alter the voltage across C5 Thus Q11 is a constant current source feeding 7 5 V zener diode VR4 4 V diode VR5 and 6 2 V temperature compensated zener diode VR6 4 36 Resistors R30 and VR8 form a voltage divider across the stable 12 4 volts developed by VR1 The base emitter junction of Q9 is therefore held
85. s per second Adjust ment of the 25 control permits adjustment of the duty cycle of the load current switching and reduction in jit ter of the oscilloscope display 5 36 The maximum load ratings listed in Figure 5 5 must be observed in order to preserve the mercury wetted relay contacts Switching of larger load currents can be accomplished with mercury pool relays with this techni que fast rise times can still be obtained but the large in ertia of mercury pool relays limits the maximum repeti tion rate of load switching and makes the clear display of the transient recovery characteristic on an oscilloscope more difficult 5 37 To check the transient recovery time proceed as follows a Connect test setup shown in Figure 5 5 b Set METER SELECTION switch to mA Turn on supply and adjust voltage controls until front panel meter indicates exactly the maximum rated output current 4 Close the line switch on the repetitive load switch setup e Set the oscilloscope for internal sync and lock on either the positive or negative load transient spike f Set the vertical input of the oscilloscope for ac coupling so that small dc level changes in the output voltage of the power supply will not cause the display to shift g Adjust the vertical centering on the scope so that the tail ends of the no load and full load waveforms are symetrically displaced about the horizontal center line of the oscilloscope This center l
86. s regulator backwards a stage at a time since loop failures occur more often at the higher power levels Table 5 2 Reference Bias and Filtered DC Troubleshooting METER NORMAL PROBABLE COMMON POSITIVE VDC RIPPLE P P CAUSE 515 pope pepe _ poem _ 150 15 0 V 6212B 6212B CR15 CR18 C9 R32 T1 C11 6214 CR15 CR18 C9 R32 T1 C11 62168 CR15 CR16 C9 C11 C12 R32 T1 6218B CR15 CR16 C9 C11 C12 R32 T1 t 2 2V 6214B t 4 5 V 6216B 78 7 8 V 6218B Low Output Ensure that the front panel Or No Out meter is not defective then put Voltage refer to paragraph 5 58 Inability To Output voltage control R10 Reach OV defective 1 mV Output Amplifier Q1 Q2 defective High Out Ensure that the front panel put Voltage meter is not defective then refer to paragraph 5 58 Oscillates C3 R17 defective G Slow Drift Measuring equipment Reference diode VR6 Never set the output voltage controls to zero 01 or 02 volts when there high or low output voltage Insufficient warm up time damage to the voltage controls could result should be 30 minutes 5 10 Table 5 3 Overall Troubleshooting Continued PROBABLE CAUSE SYMPTOM PROBABLE CAUSE Check operating setup for Poor Stability Check 6 2 reference ground loops Constant voltage Table 5 2
87. scription 028 230 V 50 400 Hz Single Phase Output Factory modification con sists of reconnecting the input transformer for 230 Vac operation Refer to Section II for further details 910 One additional operating and ser vice manual shipped with the power supply 1 9 ACCCESSORIES 1 10 The accessories listed in the following chart may be ordered with the power supply or separately from your local Hewlett Packard field sales office refer to list at rear of manual for addresses HP Part No Description 14521B 3 1 2 High Rack Kit for mounting up to three BENCH supplies Refer to Section II for details 1 11 INSTRUMENT AND MANUAL IDENTIFICATION 1 12 Hewlett Packard power supplies are identified by a two part serial number The first part is the serial number prefix a number letter combination that denotes the date of a significant design change and the country of manufacture The first two digits of the prefix indicate the year 20 80 21 81 etc the second two digits indicate the week and the letter A designates the USA as the country of manufacture The second part of the serial number is a different sequential number assigned to each power supply starting with 00101 1 13 If the serial number on your instrument does not agree with those on the title page of this manual a yellow change sheet supplied with the manual defines the dif ference between your instrument and the instrument described by this m
88. shown in Figures 5 3B or 5 3C b Adjust VOLTAGE control until front panel meter indicates the maximum rated output voltage The observed ripple and noise should be less than 200 Vrms and 1 mV 5 29 Noise Spike Measurement When a high fre quency spike measurement is being made an instrument of sufficient bandwidth must be used an oscilloscope with a bandwidth of 20 MHz or more is adequate Measuring noise with an instrument that has insufficient bandwidth may conceal high frequency spikes detrimental to the load 5 30 The test setups illustrated in Figures 5 3A and 5 3B are generally not aceptable for measuring spikes a differential oscilloscope is necessary Furthermore the measurement concept of Figure 5 3C must be modified if accurate spike measurement is to be achieved a As shown in Figure 5 4 two coax cables must be substituted for the shielded two wire cable b Impedance matching resistors must be in cluded to eliminate standing waves and cable ringing and the capacitors must be connected to block the DC current path 6 The length of the test leads outside the coax is critical and must be kept as short as possible the blocking capacitor and the im pedance matching resistor should be con nected directly from the inner conductor of the cable to the power supply terminals d Notice that the shields of the power supply end of the two coax cables are not con nected to the power supply ground
89. supply has no moving parts TEMPERATURE RANGES Operating 0 to 55 C Storage 40 to 759 C TEMPERATURE COEFFICIENT SIZE See Figure 2 1 Constant Voltage Less than 0 0296 1 mV output change per degree centigrade change in ambient follow ing 30 minutes warm up Constant Current Less than see table output change per degree centigrade change in ambient follow ing 30 minutes warm up 6212A 0 5 mA WEIGHT 4 75 Ibs 1 2 kg net 6 75 Ibs 3 1 kg shipping FINISH Dark gray 6214B Es 6 mA POWER CORD 6216B 2 A 3 wire 5 foot 1 52 cm power cord is provided with 62188 1 mA each unit Section II INSTALLATION 5 36 136 14 1 528 pl 592 83 31mm 150 37 mm REAR TOP 7 35 186 69 mm 2 47 88 14 Figure 2 1 Outline Diagram 2 1 INITIAL INSPECTION 2 2 Before shipment this instrument was inspected and found to be free of mechanical and electrical defects As soon as the instrument is unpacked inspect for any damage that may have occurred in transit Save all pack ing materials until the inspection is completed If damage is found file claim with carrier immediately Hewlett Packard Sales and Service office should be notified as soon as possible 2 3 Mechanical Check 2 4 This check should confirm that ther are no broken knobs or connectors that the cabinet
90. t voltage operation of the supply MONITOR HERE Figure 5 1 Front Panel Terminal Connections 5 13 Rated Output and Meter Accuracy 5 14 Voltage To check the output voltage proceed as follows a Connect load resistor indicated in Figure 5 2 across the output terminals of supply b Connect voltmeter accross and ter minals of supply observing correct polarity Set METER SELECTION switch to VOLTS and turn on supply d Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage e Voltmeter should indicate maximum rated output voltage within 490 POWER SUPPLY UNDER TEST MODEL NO RL IKQ IOW 5596 101 10 5 651 0 5 250 0 10 5 62128 62148 62168 62188 PRECISION VOLTMETER Figure 5 2 CV Load Regulation Test Setup 5 15 Load Regulation Definition The change the static value of dc output voltage resulting from a change in load resistance from open circuit to a value which yeilds maximum rated output current or vice versa 5 16 To check the constant voltage load regulation proceed as follows a Connect test setup as shown in Figure 5 3 b Set METER SELECTIOON switch to mA position 553 6 Turn on supply and adjust VOLTAGE con trols until front panel meter indicates max imum rated output current d Read and record voltage indicated on voltmeter e Disconnect load resistor
91. tects the power supp ly for all overloads including a direct short circuit placed across the output terminals in constant voltage operation LOAD REGULATION Constant Voltage Less than 4 mV 8 mV 6212B for a load current change equal to the current rating of the supply Constant Current Less than 500 for a load voltage change equal to the voltage rating of the supply METER The front panel meter can be used as a voltmeter or an ammeter LINE REGULATION Constant Voltage Less than 4 mV for 1096 change in the nominal line voltage at any output voltage and current within rating Constant Current Less than 500 A for 1096 change in the normal line voltage at any output voltage and current within rating OUTPUT CONTROLS Concentric coarse and fine voltage controls and con centric coarse and fine current controls set desired out put voltage current Meter switch selects voltage or current OUTPUT TERMINALS Three output terminals are provided on the front panel They are isolated from the chassis and either the positive or negative terminal may be connected to the chassis through a separate ground terminal RIPPLE AND NOISE Constant Voltage Less than 200 V rms 1 mV dc to 20 Mhz Constant Current Less than 150 dc to 20 MHz COOLING Convection cooling is employed The
92. the desired output voltage Further assume that the output voltage instan taneously rises increases due to a variation decrease in the external load circuit 4 14 Note that the change may be in the form of a slow rise in the output voltage or a positive going AC signal An AC signal is coupled to Q1 through capacitor C1 and a DC voltage is coupled to Q1 through R10 4 15 The increase in output voltage causes the voltage at the base of 01 to decrease go negative 01 now decreases its conduction and its collector voltage rises The positive going error voltage is amplified and inverted by 04 and fed to the base of series transistor O7 via emitter follower Q5 The negative going input causes O7 to decrease its conduction so that it drops more of the supply voltage and reduces the output voltage to its original level 6212B only zener diode VR9 limits the voltage swing across Q5 and Q7 and thus minimizes the dissipation of Q5 4 16 If the external load resistance is decreased to a certain crossover point as discussed in Paragraph 4 6 the output current increases until transistor 012 begins to conduct During this time the output voltage has also decreased to a level so that the base of Q1 is at a high positive potential With Q1 in full conduction its collec tor voltage decreases by the amount necessary to back bias OR gate diode CR5 and the supply is now in the con stant current mode of operation The operation of the feedback
93. tput current is maintained at the proper level 4 26 Capacitor C4 in conjunction with Z1K helps stabilize the feedback loop Diode CR20 limits voltage ex cursions on the base of Q12 4 27 Voltage Clamp Circuit 4 28 During constant current operation the constant voltage programming resistors R10A and B are a shunt load across the output terminals of the power supply If the output voltage varies the current through these resistors would tend to change resulting in an output cur rent change The clamp circuit is a return path for the voltage programming current the current that normally flows through the programming resistors The circuit maintains the current into the base of O1 constant thus eliminating the error due to shunting effects of the con stant voltage programming resistors 4 29 The voltage divider 21 21 VR2 back biases CR3 and Q3 during constant voltage operation When the power supply goes into constant current opera tion CR3 becomes forward biased by the collector voltage of Q1 This results in conduction of Q3 and the clamping of the summing point at a potential only slightly more negative than the normal constant voltage poten tial Clamping this voltage at approximately the same potential that exists in constant voltage operation results in a constant voltage across and consequently a cons tant current through pullout resistor R12 4 30 Driver and Error Amplifier 4 31 The error and driver amplfie
94. wirewound Watt Table 6 5 Manufacturer s Federal Supply Codes Allen Bradley Co Milwaukee WI General Electric Co Auburn NY Semiconductor Products Department Motorola Semiconductor Products Inc Phoenix AZ Mepco Electra Corp Columbus SC Edison Elek Division McGraw Edison Manchester NH Mepco Electra Corp Mineral Wells TX Corning Glass Works Bradford PA Hewlett Packard Co Palo Alto CA Sprague Electric Co North Adams MA Table 6 4 621 14 16 18 Parts List HP Description Mfr Part No Part No Al MAIN BOARD NOT ASSIGNED 80 1835 fxd elect 68uF 20 15V 150D686X0015R2 160 0157 fxd film 4700pF 10 200V 60 0159 fxd film 6800pF 10 200V 60 0159 fxd film 6800pF 10 200V 160 0157 fxd film 4700pF 10 200V 60 2061 fxd cer 100pF 10 lkVdc 2160 0157 fxd film 4700pF 10 200V 160 0157 fxd film 4700pF 10 200V 60 0157 fxd film 4700pF 10 200V 0 1852 fxd elect OuF 75 10 50V 0 1884 fxd elect 100 10 65V 0 1852 fxd elect 75 10 50V 0 1852 fxd elect 75 10 50V 0 0161 ASSIGNE 0 3070 mica 100 5 300V 0 3070 mica 1 5 300V 0 3070 mica lLOOpF 5 300V USED 0180 1885 elect 200uF 75 10 250V 0180 1916 elect 2000uF 100 105 28V 0180 1888 elect 490uF 475 105 85V 87 655 8 0180 1887 elect 400uF 65 10 150V 0150 0024 02uF 80 20 600V 0150 0024 cer 02uF 80 20 600V 0150 0024 cer 02uF 80 20 600V 0150 0024 cer 02u
95. without loss of regulation and possible damage to the output capacitor To avoid these effects it is necessary to preload the supply with a dummy load resistor so that the power supply delivers current through the entire operating cycle of the load device 3 26 Reverse Voltage Protection A diode is con nected across the output terminals with reverse polari ty This diode protects the output electrolytic capacitors and the series regulator transistors from the effects of a reverse voltage applied across the output terminals For example in series operation of two supplies if the AC is removed from one supply the diode prevents damage to the unenergized supply which would otherwise result from a reverse polarity voltage 3 27 Since series regulator transistors or driver tran sistors cannot withstand reverse voltage another diode is connected across the series transistor This diode pro tects the series transistors in parallel or Auto Parallel operation if one supply of the parallel combination is turn ed on before the other Section IV PRINCIPLES OF OPERATION R R S ON OFF SWITCH NOTE MAIN SUPPLY OUTPUT VOLTAGES ARE MODEL 62128 62148 62168 6218B REFERENCE REGULATOR 09 011 SERIES 1 REGULATOR 07 DRIVER Q5 RIIB COARSE CURRENT CONSTANT CURRENT INPUT AMPL 012 013 RIIA FINE CURRENT CIRCUIT 52 RESISTOR CONSTANT VOLTAGE PULLOUT ERROR AMP

HP 6212B User's Manual

Contents

Download Pdf Manuals

Related Search

Related Contents