HP 6826A User's Manual
Contents
1. POWER AMPLIFIER SPECIFICATIONS Ay at low range X1 Re TEN 10 24 x 10 Output f 10Rg Model 6825A Ay at high range X10 ee oI 10 24 x 10 Voltage X1 Range 10V p p Voltage X10 Range 100V p p Model 6827A Current 1A peak 2Re Ay at XI Model 6827A aie 10 24 x 10 Voltage X1 Range 20V p p 20R Voltage X10 Range 200V p p Ay at high range X10 a 24 x Current 5A peak 1 4 Table 1 1 Specifications Model s6826A and 6827A Continued Variable Accuracy Accuracy in high range at 10O0Hz using an external control resistance Rg at output voltage VO Rg is the accuracy of the control resistance RF Model 6826A 05 RE Vo SmV 05 ARF Yo 10mV Model 6827A Remote Voltage Control Coefficient Fixed gain amplifier mode voltage coefficient 1 14 OPTIONS 1 15 Options are customer requested factory modifica _ tions of a standard instrument The option described below applies to Models 6826A and 6827A Option No Description 007 Ten turn Output Voltage Control Replaces standard single turn voltage control to allow greater resolution in setting the output volt age ir gain of the BPS A Shunt resistor AiR53 as well as standard VOLTAGE con trol HP Part No 2100 3272 A5R2 must be removed when the ten turn output volt age control HP Part No 2100 1867 is in stalled in the A5R2 location 1 16 ACCESSORIES 4 17 The accessories l2. 35mV Voltage X10 Range 01 3mV Current 02 50uA Model 6827A Voltage X1 Range 01 7mV Voltage X10 Range 01 6mV Current 02 50uA Drift Stability Change in output de to 20Hz over 8 hour interval under constant line load and ambient following 30 minutes warm up Model 6826A Voltage X1 Range 03 ImV Pot wiper jump effect may add 5mV Voltage X10 Range 03 10mV Pot wiper jump effect may add 50mV Current 1 200uUA Pot wiper jump effect may add 1 5mA Model 6827A Voltage X1 Range 03 2mV Pot wiper jump effect may add 5mV Voltage X10 Range 03 20mV Pot wiper jump effect may add 100mV Current 1 200uA Pot wiper jump effect may add 1mA Load Effect Transient Recovery Load Transient Recovery Time required for output voltage recovery to within the specified level of the nominal output voltage following a change in output current equal to the current rating of the supply 1OOusec is required for output voltage recovery within 50mV of nominal output voltage Model 6827A l 100usec is required for output voltage recovery within 100mV of nominal output voltage Resolution Typical output voltage or current change that can be obtained using front panel controls 1 3 Model 6826A Voitage X1 Range 10mV Voltage X10 Range 100mV Current 3mA Model 6827A Voltage X71 Range 20mV Voltage X10 Range 200mV Current 1 5mA Output impedance
3. Lo HE ec em aug REMOTE RANGE CONTROL CONSTANT CURRENT CON STANT VOLTAGE PROGRAMMING CONSTANT CURRENT FLAG OUTPUT PROGRAM INTERRUPT CONSTANT RELAY CONTROL CURRENT PROGRAMMING i A fon Figure 3 3 Rear Terminal Strip 3 24 LOCAL PROGRAMMING 3 25 The BPS A is shipped with its rear terminal strap ping connections arranged for constant voltage constant current local programming local sensing single unit mode of operation This strapping pattern is illustrated in Figure 3 4 Also the Local Auto switch on board A2 see Para graph 3 54 is in the Local position when the instrument is shipped from the factory This switch must be in the Local position for single unit mode of operation 3 26 The operator selects either power supply variable gain amplifier or fixed gain amplifier operation MODE switch and also selects either constant voltage or a constant current output using the front panel VOLTAGE and CUR RENT controls for local programming no strapping changes are required Constant voltage or constant current opera tion are selected as described in the following paragraphs AB AG AIO AR AI Al3 Al4 gipelelaigl AlS AIG Al AIB Aig a ARI Figure 3 4 Normal Strapping Pattern LOCAL Programming 3 27 Constant Voltage To select a constant voltage output proceed as follows a Remove load from output terminals turn on supply and adjust VOLTAGE control for desired ou
4. 1972 13 1973 20 1980 etc the second two digits indicate the week 01 through 52 and the letter YA G J or U designates the U S A West Germany Japan or the United Kingdom respectively as the country of manufacture The third part is the power supply serial number a different 5 digit sequential number is assigned to each power supply starting with 00101 1 20 H the serial number prefix on your unit does not agree with the prefix on the title page of this manual change sheets supplied with the manual or manual backdating changes in Appendix A define the differences between your instrument and the instrument described by this manual 1 21 ORDERING ADDITIONAL MANUALS 1 22 One manual is shipped with each instrument Add itional manuals may be purchased from your local Hewlett Packard field office see list at rear of this manual for add resses Specify the model number serial number prefix and HP part number shown on the title page SECTION H INSTALLATION 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 received proceed as instructed in the following paragraphs 2 3 MECHANICAL CHECK 2 4 if external damage to the shipping carton is evident ask the carrier s agent to be present when the instrument is unpacked Check the instrument for external damage such as broken controls o
5. Typical to 50kHz Approximated by a resistance in series with an induc tance constant voltage operation Model 6826A imQ amp 1 5uH Model 6827A 2mQ amp 4uH DC Output Isolation Supply may be floated at up to 300V above ground Remote Resistance Programming Model 6826A Resistance Coefficient Voltage X1 Range 20002 V 1 Voltage X10 Range 20002 V 1 Current 10Q mA 1 Model 6827A Resistance Coefficient Voltage X71 Range 100002 V 1 Voltage X10 Range 10002 V 1 Current 1082 mA 1 Remote Programming Speed 5Ousec are required to change between 1 and 99 of the maximum and voltage limits Remote Programming Temperature Coefficient _ Output change per degree Centigrade change in am bient using an external control resistor Re at output voltage VQ or current 10 T C Rg is the tem perature coefficient of the control resistance RF Model 6826A Voltage X1 Range 25mV 007 VO T C Re Vo 5 Voltage X10 Range 2 2mV 007 VQ T C Re Vo 50 Current 016 ig 33uA T C RE IQ Model 6827A Voltage X1 Range 6mV 007 VQ T C Re Vo 10 Voltage X10 Range 4mV 007 VQ T C RE Vo 100 Current 016 lo 33uA T C RE io Table 1 1 Specifications Models 6826A and 6827A Continued POWER SUPPLY SPECIFICATIONS Continued Voltage Gain High Low Range Fixed Amplifier inverting 10X h
6. a positive input A1 positive A2 negative results in a negative output and a negative input A1 nega tive A2 positive results in a positive output The front panel or remote programming voltage controls are not appli cable in this mode The programming coefficient in the fixed gain amplifier mode is as follows MAXIMUM PROGRAMMING OUTPUT COEFFICIENT MODEL i HIGH LOW HIGH LOW RANGE RANGE RANGE RANGE 6826A 10 volts 1 volt 6827A lol up volt volt 20 volts 2 voits volt volt Figure 3 7 Remote Voltage Programming Constant Voltage 3 50 Variable Gain Amplifier AC signals or a dc level positive or negative can be amplified or attenuated in the variable gain amplifier mode Figure 3 7 shows a variable de level programming voltage applied to the input termin als A1 HI IN and A2 LO IN Since the BPS A is non inverting in the variable gain amplifier mode a positive input A1 positive A2 negative results in a positive output and a negative input At negative A2 positive results in a nega tive output The other connections on Figure 3 7 are shown for local control using front pane controls however remote contro using external controls may also be employed The front panel or remote voltage controls can be used to atten uate or amplify the input as required With the front panel VOLTAGE contro or remote programming resistor set for AIS Al6 AIT AIS AI9 AZOA2I m
7. A can sink as well as source current per mitting it to serve as a variable load device The BPS A can sink up to 50 of the rated output current 1 7 AMPLIFIER FEATURES 1 8 The unit can be made to function as a variable gain or a fixed gain amplifier by setting the MODE switch to the VAR GAIN AMP or FXD GAIN AMP position When oper ating as an amplifier the BPS A can amplify externally applied ac or de signals Variable gain can be controlled locally VOLTAGE control or remotely and is accurate to 0 1 The variable or fixed gain provided is as follows Modei 6826A Variable Gain 0 2 low range 0 20 high range Fixed Gain 1X low range 10X high range Model 6827A Variable Gain 0 4 low range 0 40 high range Fixed Gain 2X low range 20X high range 1 9 The variable gain amplifier is non inverting and has a frequency response from dc to 15kHz The fixed gain amplifier is inverting and has a frequency response from dc to 40kHz 6826A or from dc to 30kHz 6827A Total harmonic distortion is 0 1 maximum 1 10 METERS 1 41 A voltmeter and an ammeter on the front panel monitor the ac or dc output voltage and current respective ly Associated front panel VOLTAGE METER and CUR RENT METER switches allow the meters to monitor either an ac or de output and also provide dual range monitoring capability for better resolution The dc meter accuracy is 3 of full scale and the ac meter accuracy is 5 of f
8. are as follows Figure 3 2 Operating Controls and Indicators DC OUTPUT VOLTAGE MODEL HIGH RANGE LOW RANGE 6826A 6827A 3 8 In variable gain amplifier operation the BPS A can amplify or attenuate an external input signal dc to 15kHz applied to the Hi and LO IN terminals The gain is variable from 0 to a maximum depending upon the RANGE switch and VOLTAGE control G settings The variable gain ranges are as follows VARIABLE VOLTAGE GAIN MODEL HIGH RANGE LOW RANGE 0 2 0 4 In fixed gain amplifier operation the BPS A inverts 50V to 50V 100V to 100V 5V to 5V 10V to 10V 0 20 0 40 6826A 6827A 3 9 3 2 and amplifies an external input signa applied to the H and LO IN terminals For fixed gain amplifier operation the 6826A has a frequency response from DC to 40kHz and the 6827 A has a frequency response from DC to 30kHz The fixed voltage gain provided in the high or low output range is as follows FIXED VOLTAGE GAIN HIGH RANGE LOW RANGE 6826A x10 XI I 6827A X20 X2 3 14 The RANGE switch D allows selection of the 3 10 high X10 or iow X1 output ranges for power supply variable gain amplifier or fixed gain amplifier operation The REMOTE position allows the high or low range to be externally selected via the rear terminal strip see Paragraph 3 45 MODEL RANGE SWITCH 3 12 VOLTAGE CONTROL 3 13 The VOLTAGE control controls the outpu
9. computer ground 3 45 The switch connected between the A11 and S terminals allows remote selection of the high X10 or low X1 range Note that the front panel RANGE switch must be in the REMOTE position in order to utilize the remote selection feature The remote de control voltage connect ions between terminals A15 and A16 activate an internal relay When the contro voltage is applied the internal re lay is energized momentarily disabling the input driver to the BPS A error amplifier This feature is used to prevent transients from affecting the output when the programming input is changed Terminal A17 provides an indication to the external programming device when the BPS A is in con stant current operation 3 46 Variable Gain Amplifier For variable gain amplifier operation an external input signal dc to 15kHz applied to terminals A1 Hi IN and A2 LO IN is amplified or atten uated The gain is variable from 0 to a maximum value as the value of Rpy varies from 0 to 20 48K ohms The variable gain at the high and low ranges is as follows 3 7 VARIABLE GAIN MODEL HIGH RANGE LOW RANGE 6826A 0 20 0 2 6827A 0 40 0 4 CAUTION The voltage applied to the input terminals Hi IN Al and LO IN A2 must not exceed 50V maximum or the instrument may be damaged 3 47 Resistance Programming Constant Current Pro gramming resistors Rpc connected as shown in Figure 3 6 can be used to contro the consta
10. of Bipolar Power Supply Amplifier BPS A models 6826A and 6827A Local and remote programming opera tions are also described 3 3 REAR TERMINALS AND AC INPUT 3 4 The Bipolar Power Supply Amplifier BPS A is shipped with the rear terminals strapped for locai program ming using front panet controls as shown in Figure 3 1 Remote programming strapping requirements are described in subsequent paragraphs The power module contains fuse 1 2A for 115Vac or 1A for 230Vac and a slide switch for connecting 115Vac or 230Vac input power to the instru ment To turn on the BPS A set the LINE switch item Figure 3 2 to ON The LINE ON indicator 3 1 STRAPS Bipolar Power Supp ly Amplifier Models 6826A and 6827A Rear View should light Fuse F1 protects the main power supply At initial turn on an interna circuit protects any loads con nected to the BPS A from turn on transients by shorting the output terminals and disabling the BPS A s power out put circuits This circuit operates similarly at turn off to protect any loads from turn off transients 3 5 OPERATING CONTROLS AND INDICATORS 3 6 MODE SWITCH 3 7 The MODE switch 3 allows the BPS A to oper ate as a power supply variable gain amplifier or a fixed gain amplifier In the power supply operation the BPS A pro vides a variable bipolar dc output voltage dependent upon the RANGE switch 4 and VOLTAGE control settings The dc output voltage ranges
11. only for auto series and auto parallel operations see Paragraphs 3 57 through 3 61 If the switch is placed in the Auto position for normal operations the BPS A output voltage could latch up maximum positive or negative output 3 21 The following turn on and checkout procedures are performed utilizing the front panel controls Figure 3 2 and the normal rear terminal strapping connections as re ceived from the factory POWER SUPPLY CHECKOUT PROCEDURE a Set front pane controls as follows MODE switch G POWER SUPPLY RANGE switch X1 VOLTAGE contro midposition CURRENT control 6 full clockwise VOLTAGE METER switch 8 low range DC CURRENT METER switch high range DC b Set LINE switch O to ON and observe that LINE ON indicator lights c Adjust VOLTAGE control 6 from full counter clockwise to full clockwise range through OV and D that maximum output is attained as indicated on meter d Set VOLTAGE METER switch to high range DC and RANGE switch 4 to X10 position e Adjust VOLTAGE control clockwise and counterclockwise through entire bipolar output voltage range through 0 and note that maximum output is attained as indicated on meter Adjust output voltage to 50V f To checkout the constant current circuit first turn off BPS A Short circuit the front panel terminals HI OUT to LO OUT g Turn on supply and observe that CURRENT MODE indicator lights and meter indicates 0
12. output voltage gain 3 56 Parallel Connections Parallel operation of BPS A is possible because of the constant voltage constant current crossover feature Two or more power supplies can be con nected 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 load must be selected so that the current limit of one supply is exceeded allowing it to operate in the constant current mode The output CURRENT controls of each power supply can be separately set 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 BPS A NOt ag ag IOAN Al2 AI3 Al4 BPS A ZAL AIS AIG Al Ald AIS AZQA I alelelalalol BPS A NO 3 AS AD AIO All Al2 Als Al4 NOTES SLL THREE UNITS MUST BE OPERATED IN THE SAME MODE 2 UNITS 2 AND 3 MUST BE FLOATED NOT CONNECTED TO CHASSIS Figure 3 19 Series Connections 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 constant current source dropping its output voltage until it equals that of the other supply The constant voltage source will deliver only that fraction of its total rated output current which is necess ary to fulfill the total current demand Figure 3 11 illust
13. remote sensing mode 3 40 REMOTE PROGRAMMING CAUTION External programming resistors must be connec ted to the appropriate rear terminals before power is applied to the instrument 3 41 The constant voltage and constant current outputs of the BPS A can be programmed controlled from a re motely located device such as HP 6940A Multiprogrammer 3 6 or HP 6941A Multiprogrammer Extenders Either a resis tance or voltage source can be used as the programming de vice The wires connecting the programming terminals on the rear of the BPS A to the remote programming device should be twisted or shielded to reduce noise pickup 3 42 Resistance Programming Constant Voltage A programming resistor Rpy connected as shown in Figure 3 6 can be used to control the voltage output or gain pro vided that the MODE switch is in the POWER SUPPLY or the VARIABLE GAIN AMP position Resistance program ming of the constant voltage output is not applicable in the FXD GAIN AMP mode of operation The VOLTAGE con trol on the front panel is disconnected disabled for the strapping connections shown in Figure 3 6 To maintain the stability and temperature coefficient of the instrument use programming resistors that have stable low noise and low temperature characteristics less than 20 ppm C Also they should operate at less than 1 30th of their wattage rat ing to minimize short term temperature effects AB A9 AO Tana AB ala i b
14. volts h Adjust CURRENT control 6 from full cw to full cew and note that minimum current is attained as indi cated on meter i Turn off supply and remove short from output term inais j Turn on supply and adjust VOLTAGE CONTROL for an output of bOV k Turn off supply and reconnect short across the HI and LO OUT terminals l Turn on supply and note that CURRENT MODE in dicator lights and meter indicates 0 volts m Adjust CURRENT control from full cw to full cew and note that minimum current is attained as indi cated on meter AD n Turn off BPS A and remove short from output term inals VARIABLE GAIN AMPLIFIER CHECKOUT PROCEDURE oO Set front panel controls as follows MODE switch VAR GAIN AMP RANGE switch 4 X1 VOLTAGE control midposition CURRENT control 6 full clockwise VOLTAGE METER switch low range AC CURRENT METER switch high range AC p Connect a 1 75V rms 100HZz input signal to the front panel input terminals HI and LO IN q Turn on supply and adjust VOLTAGE control through entire RMS range and note that maximum voltage is attained as indicated on meter 9 r Set VOLTAGE METER switch to high range AC RANGE switch O to X10 and adjust VOLTAGE control through entire RMS range and note that max imum voltage is attained as indicated on meter FIXED GAIN AMPLIFIER CHECKOUT PROCEDURES s Set MODE switch 3 to FXD GAIN AMP posi tion and increase i
15. 12 This instrument is convection cooled Sufficient space should be allotted so that a free flow of cooling air can reach the top and rear of the instrument when it is in operation t should be used in an area where the ambient temperature remains between 0 C and 55 C 2 13 OUTLINE DIAGRAM 2 14 Figure 2 1 illustrates the outline shape and dimen sions of Models 6826A and 6827A TERMINAL STRIP DETAIL OUTPUT SENSING TERM AIS AIGA ARB A13 AROA2 lala ale ee ST en eee is 273 4 ran noA co 359mm i X 0 306 23mm EGIA 68264 6827A 6 496 10 3mm 88304 BBILA 6832A Figure 2 1 Outline Diagram 2 15 RACK MOUNTING 2 46 The Model 6826A and 6827A BPS A s may be rack mounted using either the dual rack adapter kit or the com bining case with appropriate cooling kit described in Para graph 1 16 The necessary installation instructions are pro vided with the accessories Refer to Paragraph 5 91 before proceeding with the rack mounting installation instructions 2 17 INPUT POWER REQUIREMENTS 2 18 Models 6826A and 6827A may be operated contin uously from either a nominal 120 voit or 240 voit 48 63 Hz power source A two position selector switch loca ted within the a c power module on the rear panei selects the power source Before connecting the instrument to the power source check that the selector switch setting matches the nominal line voltage of the source If required move the s
16. able gain amplifier mode and the slaves must be in the fixed gain amplifier mode Also for auto series or parallel operation the master supply s Local Auto switch A281 see Figure 3 9 must be in the Loca pos ition and each slave supply must have its Local Auto switch in the Auto position The diagrams show the master strapped for local programming and with an external signal applied to the amplifier input terminals However the same auto series or auto paralle connections could be used with the master strapped for remote programming Also with the master supply in the power supply mode the external signal applied to the A1 and A2 terminals is internally disconnected 3 59 Auto Series Operation Two or more BPS A s can be connected in an auto series arrangement to obtain a high er output voltage than that available from a single supply Figure 3 12 illustrates the auto series connections for three supplies When this arrangement is used the output voltage of each slave supply varies in accordance with that of the master supply thus the total output voltage of the combin ation is determined by the master supply s front panel VOLTAGE control or remote programming input The front panel CURRENT controls or remote programming inputs of all three units are operative and the current limit is equal to the lowest setting The slave units must be floated off ground Instruments can be operated floating up to 300 volts off ground wh
17. aximum output the programming coefficient is as follows Tololale MAXIMUM PROGRAMMING OUTPUT COEFFICIENT MODEL HIGH LOW HIGH LOW RANGE RANGE RANGE RANGE 6826A 50V 5V 20 volts 2 volts 6827A 100V volt voit 40 volts With front panel VOLTAGE control or remote program ming resistor set for maximum rated output A8 A9 AIO All AI Al3 Al4d THESE SUPPLIES MUST BE ISOLATED FROM POWER GROUND 10V 4 valts volt voit Figure 3 8 Remote Voltage Programming Constant Current 3 52 Voltage Programming Constant Current Voltage 3 51 Fixed Gain Amplifier AC signals up to 40kHz programming of the output current can be accomplished in 6826A or 30kHz 6827A or a de level positive or nega all three operating modes power supply variable gain am tive can be amplified in the fixed gain amplifier mode plifier and fixed gain amplifier Positive and negative dc 3 8 A2 BOARD LOCAL AUTO SWITCH AUTO POSITION lt LOCAL POSITION TOWARD FRONT TOWARD REAR Figure 3 9 Local Auto Switch programming voltages are connected to terminals A14 and A21 respectively as shown in Figure 3 8 The positive or negative output current will vary linearly with changes in the programming voltages The output current varies at a rate determined by the programming coefficient For mod els 6826A and 6827A the programming coefficient is 1 amp 1 voit The
18. ether operated singiely or in series This limits model 6826A t50V 1 0A to six units in series and model 6827A 100V 0 5A to three units in series 3 60 For instantaneous equal voltage sharing resistors R 7 R2 or Rg must be equal Since any variation in Rq R2 or R3 will result in a change in the voltage divider ratio and hence the output of the slave supply it is important that these resistors be stable low temperature coefficient 20 ppm C or better Also they should have power rating of at least 10X their actual power dissipation The resis tors should be selected at the normal operating voltage levels so that the current through them is about 7 to 2mA 3 61 Auto Parallel Operation Two or more BPS A s can be connected in auto paralle arrangement to obtain an output current greater than that available from a single sup ply Figure 3 13 illustrates the auto parallel connections for three supplies to allow increased output current in con stant voltage operation When this arrangement is used current sharing under al load conditions is permitted under control front panel CURRENT control or remote program ming of the master supply Because the CURRENT con trols or remote programming of each slave are operative they should be set to a maximum to prevent the slave re verting to constant current operation this could occur if the master output current setting exceeded the slave s For equal current sharing the
19. grounded 3 37 REMOTE SENSING Remote sensing is used to maintain good regulation at the load and reduce the degradation of regulation which would occur due to the voltage drop in the leads between the power supply and the load Remote sensing is accom plished by utilizing the strapping pattern shown in Figure 3 5 The power supply should be turned off before chang ing strapping patterns The leads from the sensing S terminals to the load will carry much less current than the load leads and it is not required that these leads be as heavy as the load leads However they must be twisted or shielded to minimize noise pickup CAUTION Observe polarity when connecting sense leads to the load A8 AS AO All Al2Z AIS Ald eR AI AiG AIT AIS AID A2OA2I Figure 3 5 Remote Load Sensing 3 39 For reasonable load lead lengths remote sensing limits degradation of the performance of the supply How ever If the load is located a considerable distance from the supply added precautions must be observed to obtain satis factory operation Notice that the voltage drop in the load leads subtracts directly from the available output voltage Because of this it is recommended that the drop in each load lead not exceed 1 0 voit if a larger drop must be toler ated please consult an HP Sales Engineer NOTE Due to the voltage drop in the load leads it may be necessary to readjust the constant current crossover limit setting in the
20. igh range 1X low range Variable Gain Non Inverting 0 20 high range 0 2 low range Sink Current Compliance Maximum current that the supply can sink when con nected to an active toad Model 6826A Model 6827A Fixed Amplifier Inverting 20X high range 2X low range Variable Gain Non Inverting 0 40 high range 0 4 low range Frequency Response 1 3dB at full output Model 6826A Fixed Gain dc 40kHz Variable Gain de 15kHz Model 6827A Fixed Gain de 30kHz Variable Gain de 15kHz Sink current is limited to a value ranging linearly from 1A OV to 5A 50V Externally applied voltages to output terminals in excess of GOV could damage the instrument Distortion Tota harmonic distortion is 1 maximum at 100 Hz and full output Model 6827A input Impedance 10KQ Typical Fixed Gain Accuracy at 100Hz Model 6826A Low Range X1 1 5mV High Range X10 1 5mV Model 6827A Low Range X1 1 ImV High Range X10 1 10mV Remote Resistance Programming Variable Gain Ay KR era aaa where K is the constant indi 10 24 x 1034 cated and Rg is the external control resistance Model 6826A Sink current is limited to a value ranging linearly from 5A OV to 25A 100V Externally applied voltages to output terminais in excess of 125V could damage the instrument
21. il G 3 Valuetronics International Ine 1 800 552 8258 MASTER COPY BIPOLAR POWER SUPPLY AMPLIFIER MODELS 6826A AND 6827A OPERATING AND SERVICE MANUAL FOR SERIALS 13174 00101 AND ABOVE For Serials Above 1317A 00101 a change page may be included HEWLETT PACKARD Printed November 1974 HP Part No 5950 1702 SECTION GENERAL INFORMATION 1 1 DESCRIPTION 1 2 This instruction manual contains operating and service instructions for two Bipolar Power Supply Amplifiers Models 6826A and 6827A The Bipolar Power Supply Amplifier BPS A is a general purpose instrument useful in any jaboratory engaged in the research and development of electronic systems circuitry or components The BPS A can be operated as a power supply or as an amplifier Ter minais on the rear terminal strip permit access to various in ternal contro points to further expand the operational cap abilities of the unit The resulting flexibility lends the BPS A to an almost unlimited number of applications Some of these applications are outlined in Section Hl of this manual The following paragraphs describe some of the features of the BPS A as a power supply and as an amplifier 1 3 POWER SUPPLY FEATURES 1 4 The unit can be made to function as a regulated de power supply by setting the front panel MODE switch to the POWER SUPPLY position The supply can furnish either a Constant Voltage output or Constant Current out put The dc outp
22. is can appear as current flow into the HI OUT terminal when the terminal is positive or current flow out of the terminal when it is negative Figure 3 14 shows the normal operating locus of the BPS A As shown the 6826A BPS A will limit the sink current to a value ranging linearly from 1A at OV to 0 5A at 50V and the 6827A BPS A will limit sink current to a value ranging lin early from 0 5A at OV to 0 25A at 100V 3 66 An active load can easily be accommodated by the BPS A as long as the following precautions are adhered to a The active ioad must not be applied unless the BPS A is in its active state b Program to zero output before disconnecting load CAUTION Externally applied voltage to output terminals in excess of GOV 6826A or 125V 6827A could damage the instrument 50V 6826A 100V 68274 SOURCE IAI682GA 1A 6826A 0 5A 6827A O 5A 6827A SOURCE lOOV 6827A 50V 68264 Figure 3 14 6826A 6827A Output Ranges 3 12
23. isted in the following chart may be ordered with the instrument or separately from your local Hewlett Packard sales office refer to list at rear of manual for addresses HP PartNo Description 5060 8762 Dual Rack Adapter Kit for rack mounting one or two supplies in standard 19 inch rack 5060 8760 Blank Panel Filler panel to block unused half of rack when mounting only one supply 11057A Carrying handie easily attached for portabil ity and handling convenience 1052A Combining Case for mounting one or two units in standard 19 inch rack 1 5 Model 6826A Voltage X1 Range 1 volt volt 1 Voltage X10 Range 10 voits volt 1 Model 6827A Voltage X1 Range 2 volts volt 1 Voltage X10 Range 20 volts voit 1 Constant Current voltage coefficient the following applies to variable gain amplifier fixed gain amplifier and power supply modes of operation Models 6826A and 6827A 1 ampere volt t 5 5060 0789 Cooling kit for above combining case 115 Vac 50 60Hz 5060 0796 Cooling kit for above combining case 230 Vac 50 60Hz 1 18 INSTRUMENT IDENTIFICATION 1 19 Hewlett Packard power supplies are identified by a three part serial number The first part is the power supply model number The second part is the serial number prefix consisting of a number letter combination denoting the date of a significant design change and the country of manufac ture The first two digits indicate the year 12
24. leads from Ray to the load and to the terminals should be approximately equal in length To maintain instrument accuracy and stability Rm should be a stable low temperature coefficient resistor of sufficient tating to prevent any appreciable self heating typically 1 amp 2 8W 20 pom PC 1 MASTER POWER SUPPLY OR VARIABLE GAIN AMPL MODE LOCAL AUTO SWITCH IN LOCAL AB A9 AIO AH Al2 A3 Al4 aiglelel9igig ae Need Nua AIS AIS AIT AIS AIG A20 aziPM eleje elelgl SLAVE FIXED GAIN AMPL MODE LOCAL AUTO SWITCH IN AUTO AB AQ AIO All AIZAIZ Al4 AIB AIG AIT AIB AIS A20 AZ elelejelglgle SLAVE 2 FIXED GAIN AMPL MODE LOCAL AUTO SWITCH IN AUTO AB AS AIO All AI AIS AIS alelelalalele a A a AIS AIG AF AIB AID A20 Az Figure 3 13 Auto Parallel Connections Three Units 3 62 BIPOLAR OVERVOLTAGE AND OVERCURRENT LIMIT 3 63 Bipolar overvoltage and overcurrent limit circuits prevent excessive BPS A voltage or current outputs The voltage limiting circuit prevents the output voltage from ex ceeding approximately 55 volts 6826A or 110 volts 6827A The current limiting circuit limits the transient output current to a value approximately two times the max imum rated output of 1 0A 6826A or 0 5A 6827A 3 64 REVERSE VOLTAGE AND CURRENT LOADING 3 65 Current limit circuits also protect the BPS A from active loads that force energy in or out of the BPS A sink condition Th
25. maximum positive value DC accuracy is 3 of full scale The lower scale reads the RMS output voltage from 0 to a maximum tevel AC accuracy is t5 of full scale The volt meter ranges selected by the VOLTAGE METER switch are as follows VOLTMETER RANGES MODEL 6826A Oto t6V 0 to t60V_ 0 4V uncal 0 40V 6827A Q to 12V 0 tot 120V 0 8V uncal 0 80V 3 18 CURRENT METERING 3 19 The CURRENT METER switch permits monitoring the DC or AC output current on ammeter The shaded area on the ammeter face indicates the amount of output current that is available in excess of the normal 3 3 rated output The ammeter upper scale reads the bipolar DC current from a maximum negative value through OA to a maximum positive value DC accuracy is t3 of full scale The lower scale reads the RMS output current from 0 to a maximum level AC accuracy is 5 of full scale The am meter ranges selected by the CURRENT METER switch are as follows AMMETER RANGES MODEL 0 to 0 12A 0 to 1 2A 0 to 0 08A 0 to 0 8A 0 to 0 06A 0 to 0 6A 0 to 0 04A 0 to 0 44 6826A 6827A 3 20 TURN ON CHECKOUT PROCEDURES CAUTION Rear terminal strip cover must be in place when instrument is in use Also the Local Auto switch located inside the unit on board A2 see Figure 3 9 is in the Local position toward rear of unit as shipped from the factory The Local positions is used for normal operations The Auto position fs used
26. maximum rated output current for the 6826A is 1A therefore the maximum programming voltage for 6826A is 1 volt The maximum rated output current for the 6827A is 0 5A therefore the maximum programming voltage for 6827A is 0 5V 3 53 SERIES AND PARALLEL CONNECTIONS 3 54 The following paragraphs describe the connections required for combining BPS A s for series and parallel oper ations These connections are employed whenever it is re quired to extend the voltage gain or current capability be yond one supply For series operation the total output voltage gain is the sum of the voltages gains of the individ ual supplies For parallel operation the total output current is the sum of the output current from the individual supplies For series or parallel operation the BPS A s must be opera ted in the same mode power supply variable gain amplifier or fixed gain amplifier Also each supply must have its Auto Local switch A251 see Figure 3 9 in the Loca posi tion pushed toward the rear of the instrument Note that the external signal applied to the A1 and A2 terminals is in ternally disconnected when the BPS A s are in the power supply mode 3 55 Series Connections Two or more supplies may be connected in series to obtain a higher voltage gain than is availabie from a single supply Figure 3 10 illustrates the series connections for three supplies Each of the supplies must be adjusted in order to obtain the desired
27. nput signal to 3 5V rms t Adjust VOLTAGE control through entire RMS range and note that maximum voltage is attained as indicated on meter 3 22 OPERATING MODES CAUTION Rear terminal strip cover must be in place when instrument is in use 3 23 The position of the front panei MODE switch de termines whether the instrument wili be used as a power supply or an amplifier In addition the instrument may be controlied locally using the front panel VOLTAGE and CURRENT controls or remotely via terminals on the rear of the unit The front pane output terminals HI and LO OUT and input terminals HI and LO IN are repeated as and and A1 and A2 respectively on the rear termin al strip The rear terminal strip includes sensing S and S terminals and other terminals for remote control of the BPS A as shown in Figure 3 3 These terminals connect to various control points within the instrument and allow strapping connections to be made which enabie the power supply or amplifier to be utilized in many applications The following paragraphs describe the procedures for utilizing the various operational capabilities of the power supply A more theoretical description concerning the operational features of this supply is contained in Application Note 90 and in various Tech Letters Copies of these can be obtained from your local Hewlett Packard field office SENSE TERMINALS SIGNAL INPUT TERMINALS OUTPUT TERMINALS
28. nt current output The front panel CURRENT control is disconnected disabled when the remote Rpc resistors are connected as indicated Resistance programming of the constant current output can be accomplished in all three modes of operation power supply variable gain amplifier and fixed gain amplifier individual Rpc resistors control positive and negative con stant current outputs respectively The positive or negative output current is variable at a rate determined by the pro gramming coefficient as follows PROGRAMMING COEFFICIENT OUTPUT CURRENT 10 ohms mA 1 10 ohms mA 1 0 to 1 024A Oto 512A Precision programming resistors 0 05 must be used CAUTION A load must be maintained at all times during constant current operation The load can be a 100KQ resistor for the 6826A or a 400K resistor for the 6827A 3 48 Zero output current for zero programming resis tance can be assured through proper adjustment of the front panel and ZERO ADJ potentiometers see Paragraph 5 107 3 49 Voltage Programming Constant Voltage Voltage programming of the output voltage can be accomplished in the variable gain or fixed gain amplifier mode of operation Voitage programming is not applicable in the power supply mode Figure 3 7 shows a variable dc level programming voltage applied to the Hi A1 and LO A2 input terminals Since the BPS A provides an inverted output in the fixed gain amplifier mode
29. of the instrument can be preserved if the following simple precaution is observed when driving reactive loads Always set program the VOLT AGE control for zero output before removing a capacitive load or interrupting an inductive load 3 33 CONNECTING LOAD 3 34 tach load should be connected to the power sup ply output terminals front or rear using separate pairs of connecting wires This will minimize mutual coupling ef fects between loads and will retain full advantage of the low output impedance of the power supply Each pair of connecting wires should be as short as possible and twisted or shielded to reduce noise pickup If a shielded pair is used connect the shield to ground at the power supply and leave the other end unconnected 3 35 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 should be separately connected to the remote distribution terminals For this case remote sensing should be used Refer to Paragraph 3 39 3 36 Always use two leads to connect the load to the supply regardless of where the setup is grounded This will eliminate any possibility of output current return paths through the power source ground The supply can also be operated up to 300Vdc above ground if neither output ter minal is
30. on ok un Ie CONTROL VOLTAGE CURRENT FLAG X MUST BE ISOLATED FROM CONTROL GROUND NEGATIVE Figure 3 6 Remote Resistance Programming Constant Voltage Constant Current 3 43 Power Supply For power supply operation the bipolar output voltage varies linearly from a maximum neg ative value through zero to a maximum positive value accord ing to the value of the programming resistance Rpy The voltage output ranges and corresponding values of Rpy are as follows 6826A 6827A HIGH LOW HIGH LOW RANGE RANGE RANGE RANGE 12V 102 4V OV 5 12V OV 102 4V 3 44 As noted above the output voltage should be zero volts with 10 24K connected to the programming terminals The output may be adjusted to zero by adjusting the V ZERO ADJ potentiometer as described in Paragraph 5 104 The output voltage varies from the maximum negative value to the maximum positive value through 0 at a rate deter mined by the resistance programming coefficient as follows Rev VALUE 10 24V OV 10 24V 0 10 24KQ 20 48K22 PROGRAMMING COEFFICIENT MODEL HiGH RANGE LOW RANGE 2000 ohms volt 1 1000 ohms volt 1 200 ohms volt t 1 100 ohms volt 1 68326A 6827A Precision programming resistors 0 05 must be used CAUTION When remote control programming ts employed the FLAG A17 and REMOTE RANGE A771 programming connections must be isolated from the
31. r connectors and dents or scratches on the panel surfaces If the instrument is damaged file a claim with the carrier s agent and notify your local Hewlett Packard Sales and Service Office as soon as possible see list at rear of this manual for addresses 25 ELECTRICAL CHECK 2 6 Check the electrical performance of the instrument as soon as possible after receipt Section V of this manual contains performance check procedures which will verify in strument operation within the specifications stated in Table 1 1 This check is also suitable for incoming quality control inspection Refer to the inside front cover of the manual for the Certification and Warranty statements 2 7 REPACKAGING FOR SHIPMENT 2 8 To insure safe shipment of the instrument it is recommended that the package designed for the instrument be used The original packaging material is reusable If it is not available contact your jocal Hewlett Packard field office to obtain the materials This office will also furnish the add ress of the nearest service office to which the instrument can be shipped Be sure to attach a tag to the instrument speci fying the owner model number full serial number and ser vice required or a brief description of the trouble 2 9 INSTALLATION DATA 2 10 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 for operation 2 1 2 11 LOCATION 2
32. rates the parallel connections for three units 2 9 p OF GT N ar AQ AiO Ail Ai2 AIR AIG AIS Ale AIT AIS AIS A20 AZ H A NOTES ALL THREE UNITS MUST BE OPERATED IN THE SAME MODE 2 UN ITS 2 AND 3 MUST SE FLOATED NOT CONNECTED TO CHASSIS Figure 3 11 Parallelt Connections 3 57 AUTO SERIES AND AUTO PARALLEL CONNECTIONS 3 58 The following paragraphs describe the connections required for combining BPS A s in auto series and auto 3 10 MASTER POWER SUPPLY OR VARIABLE GAIN AMPLIFIER MODE LOCAL AUTO SWITCH IN LOCAL AB AD Aid Ali A2 AIZ Al4 fais LLP Kirai AIS AG AI7 AIB AID AZO AZI SLAVE f FIXED GAIN AMPL MODE LOCAL AUTO SWITCH iN AUTO A8 A9 AIO AH AIZ AIS Al4 AI5 AI6 AIF AIB AS AZO A2I SA A 3 T FIXED GAIN AMPL MODE LOCAL AUTO SWITCH IN AUTO Figure 3 12 Auto Series Connections Three Units parallel These connections are employed whenever it is re quired to extend the voltage gain or current capability be yond one supply For auto series operation the output voit age of each slave supply varies in accordance with that of the master supply For auto paratle operation complete control of the output current from one master is allowed Diagrams are included for the strapping connections re quired between master and slaves for both auto series and auto parallel operations In either case the master must be in the power supply or vari
33. t level power supply operation or gain variable gain amphi fier operation of the BPS A In power supply operation the VOLTAGE control varies the output voltage from a maximum negative value full counterclockwise through zero midposition to a maximum positive value full clock wise In variable gain amplifier operation the gain is vari able from zero to the maximum gain as the VOLTAGE con trol is varied from full counterclockwise to full clockwise In fixed gain amplifier operation the VOLTAGE control does not control circuit operation 3 14 CURRENT CONTROL 3 15 The CURRENT control 6 sets the constant current output of the BPS A This control is operable in ail three modes of operation power supply variabie gain ampli fier and fixed gain amplifier and controis the output cur rent from 0 to the maximum rated output 1 0A for the 6826A and 0 5A for the 6827A When the instrument switches from constant voltage to constant current operation the CURRENT MODE indicator Q tights Selection of constant voltage or constant current operation is described in Paragraphs 3 27 and 3 28 3 16 VOLTAGE METERING 3 17 The VOLTAGE METER switch permits mon itoring the DC or AC output voltage on voltmeter The shaded area on the voltmeter face indicates the amount of output voltage that is available in excess of the normal rated output The voltmeter upper scale reads the bipolar DC voltage from a maximum negative value through OV to a
34. tput voltage b Short output terminals and adjust CURRENT con trol for maximum output current allowable current limit as determined by load conditions and voltage range selected in step a If a load change takes place and causes the out put current to exceed this setting the power supply will automatically crossover to constant current mode and out put current will be constant at the level set by the CORRENT control The CURRENT MODE indicator will come on and output voltage will drop proportionately to maintain com stant current 3 28 Constant Current To select a constant current output proceed as follows a Short output terminals and adjust CURRENT con trol for desired output current b Open output terminals and adjust VOLTAGE con troi for maximum output voltage allowable as determined by load conditions and current selected in step a Ifa load change causes the voltage to tise the power supply will automatically crossover to constant voltage at the voltage setting and output current will drop proportionately 3 29 OPERATION OF SUPPLY BEYOND RATED OUTPUT 3 30 The shaded area on the front panel meters indicate 3 5 3 38 the amount of output voltage and current that is available in excess of normal rated output Although the BPS A can be operated in this region without damage it cannot be guaranteed to meet all of its performance specifications 3 31 REACTIVE LOAD CONSIDERATIONS 3 32 The life and performance
35. ull scale 1 12 SPECIFICATIONS 4 13 Detailed specifications for the two models are given in Table 1 1 Table 1 1 Specifications Models 6826A and 6827A NOTE Specifications apply to all models unless otherwise specified GENERAL SPECIFICATIONS Input Power i Mode 6826A 104 127 208 254Vac switchable 48 63Hz 1 0A 130W Model 6827A 104 127 208 254Vac switchabie 48 63Hz 1 2A 150W DC Output Continued Model 6827A X1 Range 10V to 10V 0 to 0 5A X10 Range 100V to 100V 0 to 0 5A Load Effect Load Regulation Voltage load effect is given for a load current change equal to the current rating of the supply Current load effect is given for a load voltage change equal to the voltage rating of the supply Model 6826A Voitage X1 Range 0 01 6mV Voltage X10 Range 0 01 imV Current 01 2504A Meters Individual voltage and current meters DC accuracy is 3 of full scale AC accuracy is 5 full scale with sinu soidal 100Hz input Meter Ranges DC Model 6826A 6V 60V 0 12A 1 24 Model 6827A 12V 120V Load Effect Load Regulation Continued 0 06A 0 6A Modei 6827A Voltage X1 Range 01 3mV Voltage X10 Range 01 1mV Current 01 2504A Meter Ranges AC Model 6826A 4V uncal 40V rms 0 08A rms 0 8A rms Model 6827A 8V uncal 80V rms 0 04A rms 0 4A rms So
36. urce Effect Line Regulation For a change in line voltage between 104 and 127Vac 208 and 254Vac at any output voltage and current within rating Mode 6826A Voltage X1 Range 01 5mV Voltage X10 Range 01 BmV Current 01 250uA Model 6827A Voltage X1 Range 01 ImV Voltage X10 Range 01 10mV Current 01 2504A Temperature Ratings Operating O to 55 C Storage 40 to 75 C Cooling Convection cooling is employed The supplies have no moving parts Dimensions See outline diagram Figure 2 1 Weight 18 Ibs 8 2 kg net 21 Ibs 9 5 kg shipping POWER SUPPLY SPECIFICATIONS Bi DC Output Voltage and current spans indicate range over which output may be varied Model 6826A X1 Range 5V to 5V 0 to 1 0A X10 Range 50V to 50V 0 to 1 0A PARD Ripple and Noise Rms p p 20Hz to 20MHz at any fine voltage and under any load condition within rating Model 6826A Voltage X1 Range 2mV rms 10mV p p Voltage X10 Range 6mV rms 35mV p p Current 8mA rms 5MA p p Voltage X1 Range 2 5mV rms 15mV p p Voltage X10 Range 10mV rms 50mV p p Current 4mA rms 5mA p p 4 2 Table 1 1 Specifications Models 6826A and 6827A Continued POWER SUPPLY SPECIFICATIONS Continued Temperature Coefficient Output change per degree Centigrade change in am bient following 30 minutes warm up Model 6826A Voltage X1 Range 01
37. ut is bi polar and is continuously adjustable from its maximum rated positive value to an equal negative continuously through zero A crossover feature automati cally changes the supply from constant voltage to constant current operation at a preset or programmed voltage current point The front pane CURRENT MODE indicator lights for constant current operation Both the supply and the load are protected against overvoltage and overcurrent conditions by internal circuits Dual output voltage ranges are provided for better resolution The front pane RANGE switch allows selection of the high X10 or tow X1 output range 1 5 The output voltage can be programmed locally using the front panel VOLTAGE control or remotely by means of a resistance connected to the appropriate rear ter minals The output current can be programmed locally us ing the front panel CURRENT control or remotely by means of a resistance or voltage source connected to the appropriate rear terminals The BPS A can be programmed controlled at a very high rate of speed iess than 5Ousec for output voltage change over the entire voltage span Local and remote programming connections are described in Section Ul The output voltage and current ranges are as follows 1 1 Model 6826A 5V to 5V at 0 to 1 0A low range 50V to 50V at 0 to 1 0A high range Model 6827A 10V to 10V at 0 to 0 5A low range 100V to 100V at 0 to 0 5A high range 1 6 The BPS
38. witch to the other position Note that the power cabie must be removed the plastic door on the power module must be moved aside the fuse extractor must be pulled out ward and the fuse must be removed in order to gain access to the selector switch 2 149 When the instrument leaves the factory the proper fuse is instailed for 115 volt operation An envelope con taining a fuse for 230 volt operation is attached to the instru ment Make sure that the correct fuse is installed if the position of the slide switch is changed 2A for 115 volt op eration and 1A for 230 volt operation 2 20 POWER CABLE 2 21 To protect operating personnel the National Elec trical Manufacturers Association NEMA recommends that the instrument pane and cabinet be grounded This instru ment is equipped with a three conductor power cable The third conductor is the ground conductor and when the cable is plugged into an appropriate receptacle the instrument is grounded The offset pin on the power cable s three prong connector is the ground connection 2 22 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 SECTION HI OPERATING INSTRUCTIONS STRAPS POWER MODULE Figure 3 1 3 1 INTRODUCTION 3 2 This section describes the operating controls and indicators the turn on checkout sequence and operating modes
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