BK Precision Triple Output Power Supply
Contents
1. 5 FEATURES 202202200 2002 5 7 SPECIFICATIONS 8 CONTROLS AND INDICATORS 10 General Controls and Indicators 10 4 6 5 V Supply Controls and Indicators 10 A Supply Controls and Indicators 12 B Supply Controls and Indicators 12 Rear Panel Controls 13 OPERATING INSTRUCTIONS 14 Safety Precautions 14 Equipment Precautions 14 Independent Use of A Or B Supply 14 Hook up 15 Typical Constant Voltage Operation 18 Setting Current Limit 19 Typical Constant Current Operation 20 Constant Voltage Current Characteristic 21 Series Tracking Operation 22 Parallel Tracking Operation 26 4 6 5 V Power Supply Operation 29 Page APPLICATION 33 General 33 Elec2. 9 digits Panel Meter Accuracy Current 0 5 9 digits see note 1 Third SUPPLY Output Voltage Range 4V to 6 5V 2V to 6 5V model 1761 Load Regulation Constant Voltage lt 10mV 0 to 5A load Line Regulation 108 132V Constant Voltage lt l 0mV Ripple and Noise lt 2mV RMS Over Voltage Protection Threshold 6 8V to 7 3V Panel Meter Accuracy Same as A Supply Meter SPECIFICATIONS GENERAL Dimensions H x W x D Power Requirements 5 7 10 5 x 15 145 mm x 267 mm x 381 mm Domestic 120 VAC 10 60 Hz Weight International 120 220 230 240 VAC 10 50 60 Hz 10 kg 21 Ibs Power Consumption Fully Loaded Accessories Supplied Approximately 350 W Two earth ground bus straps Protection Reverse polarity protection and current limiting NOTE Specifications and information are subject to change without notice Please visit www bkprecision com for the most current product information Note 1 Important Even with noticeable Thermal Drift this high resolution power supply will be considerably more accurate than any standard three digit display bench power supply Thermal Drift Since this power supply has greater resolution than standard bench power supplies they are more susceptible to Thermal Drift Thermal Drift occurs on almost every type of power supply but is more apparent on high resolution types Thermal Drift results in the metering of the power
3. A supply and connect the negative polarity of the circuit to the negative terminal of the B supply Connect the circuit ground to the ground terminal of either the A or B supply If desired set the LED displays to monitor current The load current will usually be different for each of the supplies in this configuration The advantage of this configuration over the independent one is that if the 12 V A supply is varied to simulate a 10 to 10 voltage variation the 5 Y B supply will automatically vary the same percentage 40 APPLICATIONS Select TRACKING SERIES Adjust for desired voltage Preset current Adjust for limit desired voltage Preset current limit Equipment Being Powered Fig 16 Typical Hook Up Using Different Positive and Negative Voltages and a Separate Common MAINTENANCE WARNING The following instructions are for use by qualified personnel only To avoid electrical shock do not perform any servicing other than contained in the operating instructions unless you are qualified to do so Line voltage is exposed when the top cover is removed from the power supply and is present on the fuseholder and power switch even when the unit is turned off FUSE REPLACEMENT If the fuse blows the LED indicator will not light and the power supply will not operate The fuse should not normally open unless a problem has developed in the unit Try to dete
4. supply is in the Constant Voltage mode The Power Supply regulates the output voltage at the value set by the B VOLTAGE controls 19 C C Constant Current PARallel Indicator Red LED lights when B supply is in the Constant Current mode The Power Supply regulates the output current at the value set by the B CURRENT control when in the series tracking or INDEPendent modes Also lights when the TRACKing PARallel mode is selected CONTROLS AND INDICATORS 20 21 22 23 24 25 Coarse VOLTAGE Control Coarse adjustment of the output voltage of the B supply when the INDEPendent mode is selected Also sets the 5 to 100 tracking in the SERies TRACKing mode Disabled in the PARallel TRACKing mode Read the value on the B LED Display when the voltage V metering mode is selected Fine VOLTAGE Control Fine adjustment of output voltage of the B supply when the INDEPendent mode is selected Also sets the 5 to 100 tracking in the SERies TRACKing mode Disabled in the PARallel TRACKing mode Read the value on the B LED Display when the voltage V metering mode is selected CURRENT Control Adjusts current limit of B supply in constant voltage mode Adjusts current value of B supply in constant current mode Current can be read from the B LED Display when the current A metering mode is selected Left V A Switch Selects current or voltage metering mode for the
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6. 6 5V 3 9V REF AIN BOARD the supply The functions of the adjustments are shown in Table R159 6 5V 6 8V REF AIN BOARD 2 and their locations are shown in Fig 18 R163 _ A SUPPLY A METER MAIN BOARD R164 R SUPPLY A METER MAIN BOARD I A SUPPLY AND A METERING ADJUSTMENTS R304L B SUPPLY V METER PANEL METER R304R A SUPPLY V METER f A PANEL METER 1 Connect an accurate 40 1 external 4 1 2 digit multimeter to measure the dc voltage at the output terminals of the A SUPPLY 2 Disengage the INDEP TRACK mode switch out so that the power supply is in the INDEPendent operating mode 3 Set the A VOLTAGE controls both Coarse and Fine to maximum fully clockwise 4 Adjust R6 A SUPPLY 5V REF on the main circuit board located on the right rear side of the supply for a reading as close to 30 40 volts on the multimeter as possible 5 Set the 0 30 V 4 6 5V switch to the 0 30V position and the Right V A switch to the V position 1 Adjust R304 A SUPPLY V METER ADJ on the A panel meter board located on the right side of the supply behind the A 4 6 5V LED Display for a reading of 30 4 volts on the A 4 6 5V LED Display 2 Set the A Coarse VOLTAGE control for a reading of approximately 05 0 volts on the A 4 6 5V LED Display 42 MAINTENANCE O R10 R6 B SUPPLY A SUPPLY 300 038 5V REF 5V REF MA
7. constant voltage applications a current limit may be preset When load variations cause the current to reach the preset limit the unit then regulates output current rather than output voltage Current limits are adjustable from 5 to 100 of maximum In constant current applications the maximum voltage may be preset When load variations cause current to drop below the regulated value the unit reverts to regulated voltage operation at the preset value The third V supply is ideal for powering digital logic circuitry The 0 5 amp capacity allows the supply to be used for large circuits Built in overload protection automatically limits the current output to a maximum of 5 amps An indicator lights when the supply is overloaded These models exhibit excellent regulation and low ripple characteristics The circuit design incorporates a pre regulator which greatly reduces internal power dissipation at low output voltages Reverse polarity protection prevents accidental damage to the power supply from improper connection to an external voltage and current limiting protects the equipment being powered as well as the power supply The output is isolated from chassis and earth ground which permits full flexibility of connections When needed the or polarity may be strapped to ground or either polarity may be floated to an external voltage Additionally the two main volt supplies can be used as a split supply with tw
8. current limit can be set so that all units which do not meet the load current specification will cause the CC indicator to light and the unit can be ELECTRONICS DESIGN LAB The technician or engineer working in an engineering laboratory requires a dc power supply to power breadboard and prototype circuits This power supply is ideal because it monitors output current and voltage limits current to protect the circuit is adjustable over a wide range and has excellent regulation and very low ripple Use of the instrument in an engineering laboratory is very similar to that described for servicing electronics equipment and modules except that lower currents may be prevalent when powering individual circuits The current limiting feature is very valuable in this application because it can protect unproven circuits from damage ELECTRONICS EDUCATION The student in an electronics curriculum may use the power supply for powering equipment and circuits as previously described for all other applications In addition the power supply can be used in the classroom laboratory to conduct experiments in fundamental electronics In learning Ohm s law for example the relationships of resistance current and voltage are easily demonstrated by the use of a power supply BATTERY CHARGING The power supply can be used as a battery charger to restore the charge in rechargeable batteries such as lead acid nickel cadmium and some alkaline types Refer
9. current limit in advance before connecting the load as prescribed earlier in the Setting Current Limit procedure If the load current drops below the constant current value the CC indicator will go off and the CV indicator will light In this case the power supply automatically switches to the constant voltage mode and further rotation of the CURRENT control will not increase the output current 20 OPERATING INSTRUCTIONS Read output current from display CC indicator on Preset voltage limit 1761 DC POWER SUPPLY ao RADA wem zum m Adjust to desired current Fig 6 Typical Constant Current Operation OPERATING INSTRUCTIONS Constant Voltage Constant Current Characteristic The working characteristic of this power supply is called a constant voltage constant current automatic crossover type This permits continu ous transition from constant current to constant voltage modes in re sponse to the load change The intersection of constant voltage and constant current modes is called the crossover point Fig 7 shows the relationship between this crossover point and the load For example if the load is such that the power supply is operating in the constant voltage mode a regulated output voltage is provided The output voltage remains constant as the load increases up until the point where the preset current limit is reached At that point the output current becomes constant and the output voltage
10. light 4 Set the meter selection switch to the A position to select the current metering mode 5 Adjust the CURRENT control for the desired current limit Read the current value on the LED display 6 The current limit overload protection has now been preset Do not change the CURRENT control setting after this step 7 Remove the short between the and terminals and hook up for constant voltage operation 1761 D POWER SUPPLY Select A in CC indicator on Temporarily short to Fig 5 Setting Current Limit 19 Typical Constant Current Operation 1 UY Before connecting the device to be powered to the power supply determine the maximum safe voltage to be applied set the meter selection switch to the V position and set the VOLTAGE controls to obtain that voltage reading on the LED display Determine the desired constant current value Set the CURRENT control to minimum fully counterclockwise Turn off the power supply and connect it to the device to be powered Turn on the power supply The CC indicator should light if the load is greater than 5 of full scale NOTE The CC indicator will not light if the load is less than 5 of full scale or approximately 0 1A Set the meter selection switch to the A position to obtain the current metering mode Increase the CURRENT control setting until the desired constant current value is read on the display or set the
11. negative polarity power inputs use the connection shown in Fig 8E 9 Observe proper polarity If the circuit being powered is not equipped with reverse polarity protection damage to the circuit can result from reverse polarity Use color coded hook up leads for convenience in identifying polarity red for and black for 10 Make sure that the hook up leads offer sufficient current capability and low resistance between the power supply and the circuits being powered PARALLEL TRACKING OPERATION In the parallel tracking mode of operation both supplies are strapped together in parallel This allows for a 0 30 V supply with a 4 amp current capability Only the A output terminals are used for parallel tracking operation In the parallel tracking mode the B supply output voltage and current track the A supply output voltage and current 6 Set the power supplies to the TRACKING PARALLEL mode by engaging both TRACKING switches INDEP TRACK and SER PAR switches 7 Set the 0 30V 4 6 5V switch to the 0 30V position the A V A switch to the V voltage metering position and the B V A switch to the A current metering position Output voltage will now be read from the A LED Display Output current is exactly double the value read from the B LED Display because each supply is providing the same amount of current 8 Because both voltage and current of the B supply track the A sup
12. or an isolation transformer is used b If the equipment under test is powered up and that equipment uses high voltage in any of its circuits the power supply outputs may be floated to the potential at the point of connection Remember that high voltage may appear at unexpected points in defective equipment Do not float the power supply output to more than 100 volts peak with respect to chassis or earth ground c If the equipment under test is off and that equipment uses high voltage in any of its circuits under normal operation discharge high voltage capacitors before making connections or tests Some circuits retain high voltage long after the equipment is turned off 2 Use only a polarized 3 wire ac outlet This assures that the power supply chassis case and ground terminal are connected to a good earth ground and reduces danger from electrical shock 3 Don t expose high voltage needlessly Remove housings and covers only when necessary Turn off equipment while making test connections in high voltage circuits Discharge high voltage capacitors after removing power continued on inside back cover Instruction Manual For Models 1760A and 1761 Triple Output DC Power Supplies With Dual 4 Digit LED Displays BK PRECISION si FREGE 22820 Savi Ranch Parkway Yorba Linda CA 92887 www bkprecision com TABLE OF CONTENTS page TEST INSTRUMENT SAFETY inside front cover INTRODUCTION
13. terminal of the A supply In the series tracking mode the maximum output voltage of both the A and B supplies can be simultaneously varied with one control The maximum B supply voltage can be set to the same value of the A supply by setting the B Coarse and Fine VOLTAGE controls fully clockwise so that B is set to 100 tracking Simultaneous metering of both current and voltage can be obtained in this mode of operation by setting one of the displays for current metering and one for voltage metering In this case the output voltage across the two supplies is actually double the displayed value For example if the B display is set for voltage metering and the A display for current metering the output voltage across the A positive red terminal and the B negative black terminal would be double the reading on the B LED Display since both supplies are putting out the same voltage The actual output current would be the value read from the A LED Display 8 Set the power supplies to the TRACKING SERIES mode by engaging the INDEP TRACK switch and releasing the SER PAR switch 22 OPERATING INSTRUCTIONS Set the 0 30 V 4 6 5 V switch to the 0 30 V position the B V A switch to the V voltage metering position and the A V A switch to the A current metering position Set the B Coarse and Fine Voltage and CURRENT controls to the f
14. 0 30 V B supply When in the A amps position in current is read form the B LED Display When in the V volts position out voltage is read form the B LED Display B LED Display Digital display indicates voltage or current at the 0 30 V B supply depending on the setting of the A V switch Terminal Red Positive polarity output terminal for the B supply In series tracking operation this terminal is connected to the negative terminal of the A supply 26 Terminal Green Earth and Chassis Ground 27 Terminal Black Negative polarity output terminal for the B supply Also serves as the negative polarity terminal for 0 to 60 V series tracking operation REAR PANEL CONTROLS 28 Fuse 29 Power Cord 30 110 220 Line Voltage Conversion Switch Fig 2 Rear Panel Controls OPERATING INSTRUCTIONS SAFETY PRECAUTIONS CAUTION Avoid contacting the heat sink at the rear of the power supply When the unit is providing large amounts of current at any or all of its outputs the heat sink can become very hot Contacting the heat sink when it is hot could result in skin burns or damage to the equipment in contact with them Use only a polarized 3 wire ac outlet This as sures that the power supply chassis case and ground terminal are connected to a good earth ground and reduces danger from electrical shock There may be great danger of electrical shock if
15. FETY continued from inside front cover If possible familiarize yourself with the equipment being tested and the location of its high voltage points However remember that high voltage may appear at unexpected points in defective equipment Use an insulated floor material or a large insulated floor mat to stand on and an insulated work surface on which to place equipment and make certain such surfaces are not damp or wet When testing ac powered equipment the ac line voltage is usually present on some power input circuits such as the on off switch fuses power transformer etc any time the equipment is connected to an ac outlet B K Precision products are not authorized for use in any application involving direct contact between our product and the human body or for use as a critical component in a life support device or system Here direct contact refers to any connection from or to our equipment via any cabling or switching means A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause failure of that device or system or to affect its safety or effectiveness Never work alone Someone should be nearby to render aid if necessary Training in CPR cardio pulmonary resuscitation first aid is highly recommended 48 BK PRECISION 22820 Savi Ranch Parkway Yorba Linda CA 92887 www bkprecision com 2005 B amp K Precision Corp
16. IN BOARD 4 6 5V R119 A METER B SUPPLY R122 SERIES TRACKING DO e 9 B SUPPLY 4 6 5V R159 R133 R163 A METER 3 9V REF 4 6 5V 4 6 5V A SUPPLY 6 8V REF V METER A METER Fig 18 Location of Adjustments Main Circuit Board 43 MAINTENANCE 4 5 Set the Right V A switch to the A position Connect the external multimeter across the A SUPPLY output terminals to read the output current so that the meter causes a short circuit across the terminals and adjust the A CURRENT control so that 2 00 amps is read on the A 4 6 5V LED Display Adjust R163 A SUPPLY A METER ADJ so that the multimeter also reads 2 00 amps 4 6 5V SUPPLY METERING AND 4 6 5V ADJUSTMENTS 5 6 7 8 9 Set the 0 30V 4 6 5V switch to the 4 6 5V position and the Right V A switch to the V position Connect an accurate 0 1 external 4 1 2 digit multimeter across the output terminals of the 4 6 5V SUPPLY to read output voltage and adjust the 4 6 5V front panel voltage level control to minimum 4V fully counterclockwise Adjust R134 4 6 5V 3 9V REF located on the main board for a reading of 3 90 volts on the external multimeter Adjust R133 4 6 5V V METER ADJ located on the main board so that the A 4 6 5V LED Display reads 3 90 volts Set the Right V A switch to the A position 10 Tum R122 4 6 5V A METER amp A LIMIT ADJ and R159 4 6 5V 6 8V REF locate
17. INSTRUCTION BK PRECISION MANUAL MODELS 1760A amp 1761 Manual de Instruccion Para los modelos 1760A y 1761 Triple Output DC POWER SUPPLY With Dual 4 Digit LED Displays Fuentes de Poder de Triple Salida DC C Con Pantalla tipo LED Dual de 4 Digitos ade ase BK PIERRE E Bs Gs E e TEST INSTRUMENT SAFETY WARNING Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing must sometimes be performed where exposed high voltage is present An electrical shock causing 10 milliamps of current to pass through the heart will stop most human heartbeats Voltage as low as 35 volts dc or ac rms should be considered dangerous and hazardous since it can produce a lethal current under certain conditions Higher voltages are even more dangerous Your normal work habits should include all accepted practices to prevent contact with exposed high voltage and to steer current away from your heart in case of accidental contact with a high voltage Observe the following safety precautions 1 There is little danger of electrical shock from the dc output of this power supply However there are several other possible test conditions using this power supply that can create a high voltage shock hazard a If the equipment under test is the hot chassis type a serious shock hazard exists unless the equipment is unplugged just turning off the equipment does not remove the hazard
18. arity d If the chassis or common of the equipment being powered is separate from both the positive and negative polarity power inputs use the connection shown in Fig 9D OPERATING INSTRUCTIONS Equipment Equipment Being Powered Being Powered Fig 9 Parallel Tracking Operation Grounding Possibilities 27 OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY 1 1761 DC POWER SUPPLY No Strap Equipment Equipment Being Powered Being Powered Fig 9 Parallel Tracking Operation Grounding Possibilities 28 OPERATING INSTRUCTIONS 9 Observe proper polarity If the circuit being powered is not equipped with reverse polarity protection damage to the circuit can result from reverse polarity Use color coded hook up leads for convenience in identifying polarity red for and black for 10 Make sure that the hook up leads offer sufficient current capability and low resistance between the power supply and the circuits being powered 10 amp test leads are available as an optional accessory 4 6 5 V POWER SUPPLY OPERATION The 4 6 5V supply provides a 4 0 to 6 5V DC output with a 5 amp current capacity The supply is ideal for use with TTL circuits 5 Set the 0 30V 4 6 5V switch to the 4 6 5V position and the Right V A switch to the V position This sets the A 4 6 5V Display to show output voltage of the 4 6 5V supply 6 Using the Voltage Level Control to adjust the output voltage of the 4 6 5 V supply to th
19. atories manufacturing and testing facilities schools and home hobbying The A and B power supply outputs are fully adjustable from 0 to 30 0 35 model 1761 volts and 0 to 2A 0 3 model 1761 amps and the 4 6 5V 2 6 5 model 1761 supply is fully adjustable from 4 to 6 5V with a current capability of 0 to 5 amps This flexibility makes it suitable for most applications requiring a dc power source ELECTRONICS SERVICING Most electronics troubleshooting and repair is performed on a test bench This power supply can provide the dc power source to operate a module or circuit board on the test bench when it is removed from its parent equipment It can be used to power portable battery operated equipment and check the effect of low battery voltage It can power vehicular equipment such as tape players auto sound systems CB radios etc on the test bench Parallel tracking supplies up to 4 amps adequate surge current for most vehicular equipment Most automobiles and other vehicles use 12 volt electrical systems Although the electrical system is normally referred to as a 12 volt system actual battery voltage when fully charged is approximately 14 volts The power supply may be set to 14 volts for servicing equipment from vehicles with 12 volt electrical systems Some trucks use a 24 volt electrical system bench testing of equipment from these systems should be performed at 28 volts 33 Some servicing applications require the inj
20. d on the main board fully clockwise 44 1 Connect a 1 Q load rated at 30W or more and the multimeter in series across the output terminals of the 4 6 5V SUPPLY to read the output current 2 Adjust the 4 6 5V voltage level control to obtain an output of 5 30 amps read on the multimeter 3 Adjust R122 4 6 5V A METER amp A LIMIT ADJ so that the A 4 6 5V LED Display also reads 5 30 amps 4 Slowly Adjust R159 4 65V 6 8 REF counterclockwise until the OVER indicator on the 1760 Front Panel just lights Ill B SUPPLY AND METERING ADJUSTMENTS 1 Connect an accurate 0 1 external 4 1 2 digit multimeter to measure the dc voltage at the output terminals of the B SUPPLY 2 Disengage the INDEP TRACK mode switch out so that the power supply is in the INDEPendent operating mode 3 Set the B VOLTAGE controls both Coarse and Fine to maximum fully clockwise 4 Adjust R10 B SUPPLY 5V REF on the main board for as close to 30 70 volts on the multimeter as possible 5 Set the Left V A switch to the V position 6 Adjust R304 B SUPPLY V METER ADJ on the B panel board located on the left side of the supply behind the B LED Display for a reading of 30 7 volts on the B LED Display 7 Set the B Coarse VOLTAGE control for a reading of approximately 05 0 volts on the B LED Display 8 Set the Left V A switch to the A position 9 Connect the external mu
21. drops in proportion to further increases in load The crossover point is indicated by the front panel LED indicators The crossover point is reached when the CV indicator goes off and the CC indicator comes on Similarly crossover from the constant current to the constant voltage mode automatically occurs from a decrease in load A good example of this would be seen when charging a 12 volt battery Initially the open circuit voltage of the power supply may be preset for 13 8 volts A low battery will place a heavy load on the supply and it will operate in the constant current mode which may be adjusted for a 1 amp charging rate As the battery becomes charged and its voltage approaches 13 8 volts its load decreases to the point where it no longer demands the full l amp charging rate This is the crossover point where the power supply goes into the constant voltage mode 21 Constant Current Range E Output Voltage Crossover Point it Constant Voltage Range Output Current Figure 7 Constant Voltage Constant Current Characteristics SERIES TRACKING OPERATION When the series tracking mode of operation is selected the positive red terminal of the B supply output is internally connected to the negative black terminal of the A supply This allows the power supply to be used as a single 0 to 60 volt power supply simply by using the negative black terminal of the B supply and the positive red
22. e desired level 7 Turn off the power supply and the equipment to be powered during hook up 8 Connect the positive polarity of the device being powered to the red terminal of the 4 6 5V supply 9 Connect the negative polarity of the device being powered to the black terminal of the 4 6 5V supply 29 1 Fig 10 illustrates the grounding possibilities of the 4 6 5V supply a If the negative polarity of the equipment or circuit being powered is also the chassis or common it may grounded to earth by connecting a jumper from the black terminal to either green terminal as shown in Fig 10A b Similarly the positive polarity can be grounded by connecting a jumper between the red terminal and either green terminal as shown in Fig 10B c If an earth ground reference is not required the configuration of Fig 10C may be used The scheme in Fig 10C should also be used where it is not known whether the chassis is common with either the positive or negative polarity d If the chassis or common of the equipment being powered is separate from both the positive and negative polarity power inputs use the connection shown in Fig 10D 2 Observe proper polarity If the circuit being powered is not equipped with reverse polarity protection damage to the circuit can result from reverse polarity Use color coded hook up leads for convenience in identifying polarity red for and black for 3 Make sure
23. ection of a variable dc voltage for certain tests such as checking the effect of AGC bias in a television receiver This requires an isolated dc power supply such as the Model 1760 The equipment being tested may contain its own power supply and operate from ac power A dc voltage may already be present in the circuit One polarity of the power supply output is floated to an appropriate point in the circuit such as the emitter of a transistor The other polarity of the power supply output is then applied to another point in the circuit such as the base of that transistor Varying the power supply voltage then varies the dc bias on the stage and the effects may be noted A series limiting resistor is often used to protect the circuits from overdissipation ELECTRONICS MANUFACTURING In electronics manufacturing facilities the power supply is often used as a dc power source while testing and adjusting modules subassemblies and complete units in the production and assembly area or in the quality control area The instrument can be used in incoming inspection as a dc power source for testing purchased components and subassemblies This power supply is particularly well suited for manufacturing applications because of its ease of operation and its continuous duty rating When load current or total power dissipation are among the main characteristics to be measured the total load current and voltage are easily displayed on the LED display The
24. he two supplies to be used as one 0 to 60 volt supply 3 When both INDEP TRACK and SER PAR switches are engaged in the unit is in the TRACKing PARallel mode In this mode the A and B supplies are wired together in parallel and both the maximum current and voltage are set using the A controls The A and B outputs can be used as two individual but tracking power supplies or just the A output can be used as a 0 to 30 volt supply with a 4 A capability 0 30V 4 6 5V Switch Controls A 4 6 5V LED Display When this 10 switch is in the 0 30V position out the LED display monitors the A 0 30 V supply When this switch is in the 4 6 5V position in the LED display monitors the 4 6 5V supply 4 Right V A Switch Selects current or voltage metering mode for the A 0 30 V supply or the 4 6 5 V supply depending on setting of 0 30 V 4 6 5 V switch When in the A amps position in current is read from the A 4 6 5 V LED Display When in the V volts position out voltage is read from the A 4 6 5 V LED Display 5 A 4 6 5 V LED Display Digital display indicates voltage or current at the 0 30 V A supply or the 4 6 5 V supply depending on the setting of the Right V A and 0 30 V 4 6 5 V switches 4 6 5 V SUPPLY CONTROLS AND INDICATORS 6 Terminal Black Negative polarity output terminal for 4 6 5V supply 7 Terminal Red Positive pola
25. ing hook up Connect the negative polarity inputs of the circuit to be powered to the negative black terminals of the supplies Connect the common positive input of the circuit to be powered to either supplies positive red or ground green terminal If desired set the LED displays to monitor current 38 APPLICATIONS Adjust for Preset current Ad i just for desired desired voltage limit Select INDEP voltage Preset current limit 1761 DC POWER SUPPLY Eguipment Being Powered Fig 14 Typical Hook Up Using Two Different Negative Voltages and a Common Positive APPLICATIONS Identical Positive and Negative Voltages With a Separate Set fully Common Refer To Fig 1 5 clockwise for Preset current Select TRACKING Adjust for desired 100 tracking limit SERIES voltage Another typical split supply application is when a circuit uses 4 operational amplifiers op amps Typically identical positive and current negative voltages are required to power op amp circuits Using both ms supplies and the series tracking mode of operation identical positive and negative voltages with a separate common are obtained as follows 1 Select the TRACKing SERies operating mode and set A B Metering switch to monitor the A supply 2 Set the desired voltage using the A VOLTAGE controls 3 Connect a ground wire between the A supply negative terminal and the GND green terminal Equipment 4 Turn off
26. is purpose To use this service even if the instrument is no longer under warranty follow the instructions given in the WARRANTY SERVICE INSTRUCTION section of this manual There is anominal charge for instruments out of warranty Service Information Warranty Service Please return the product in the original packaging with proof of purchase to the address below Clearly state in writing the performance problem and return any leads probes connectors and accessories that you are using with the device Non Warranty Service Return the product in the original packaging to the address below Clearly state in writing the performance problem and return any leads probes connectors and accessories that you are using with the device Customers not on open account must include payment in the form of a money order or credit card For the most current repair charges please visit www bkprecision com and click on service repair Return all merchandise to B amp K Precision Corp with pre paid shipping The flat rate repair charge for Non Warranty Service does not include return shipping Return shipping to locations in North American is included for Warranty Service For overnight shipments and non North American shipping fees please contact B amp K Precision Corp B amp K Precision Corp 22820 Savi Ranch Parkway Yorba Linda CA 92887 www bkprecision com 714 921 9095 Include with the returned instrument your complete return shipping address con
27. ltimeter across the B SUPPLY output terminals to read the output current so that the meter causes a short circuit across the terminals and adjust the B CURRENT control so that 2 00 amps is read on the B LED Display 10 Adjust R164 B SUPPLY A METER ADJ so that the multimeter also reads 2 00 amps IV B SERIES TRACKING ADJUSTMENT 4 Set the supply to the TRACKing SERies mode by engaging the INDEP TRACK switch and releasing the SER PAR switch 5 Set the B VOLTAGE controls both Coarse and Fine to maximum fully clockwise 6 Set the A VOLTAGE controls both Coarse and Fine to maximum fully clockwise 45 MAINTENANCE 1 Connect the multimeter to the A SUPPLY outputs and measure the voltage 2 Disconnect the multimeter from the A SUPPLY outputs and connect it to the B SUPPLY outputs 3 Adjust R119 SERIES TRACKING ADJ located on the MAIN board until the voltage read from the multimeter is the same as it was across the A SUPPLY output terminals Return the multimeter to the A SUPPLY output terminals and verify that the output voltage is identical If not repeat this step INSTRUMENT REPAIR SERVICE Because of the specialized skills and test equipment required for instrument repair and calibration many customers prefer to rely upon B K Precision for this service We maintain a network of B K Precision authorized service agencies for th
28. n positive or one positive and one negative with a common ground In addition each of these configurations can be obtained with identical or differing voltages APPLICATIONS Two Identical Positive Voltages With a Common FEDD Adjust for desired Preset current elec RA Negative Refer To Fig 11 BARA TEL voltage limit Some electronic eguipment reguires two identical positive voltages with a common negative A good example of this would be a digital car clock where there are two 12 volt inputs and a common negative Using both supplies in the parallel tracking mode would provide the simplest hook up and operation This type of split supply operation is obtained as follows 1 Connect a ground strap between the A supply s negative terminal and ground 2 Set the desired voltage and maximum current using the A VOLTAGE and CURRENT controls 3 Turn off the power supply and the eguipment to be powered Eguipment during hook up Peng Cewe 4 Connect the positive polarity inputs of the circuit to be powered to the positive red terminals of the supplies and connect the common negative input of the circuit to be powered to the A supply s negative black or ground green terminal Fig 11 Typical Hook Up Using Two Identical Positive Voltages and a Common Negative 35 Two Differing Positive Voltages With a Common Negative Refer To Fig 12 Many electronic circuits require two different positive v
29. o positive voltages and a common negative two negative voltages and a common positive or one positive one negative and a common All of these configurations can be used with either matching tracking or differing independent voltages The features and versatility of the unit especially the triple output and tracking features make it an ideal general purpose power supply for engineering lab applications It can serve as a single or multi voltage power source including the bias supply for breadboard and prototype circuits and equipment It can provide single or simultaneously varying voltages for circuit evaluation It can provide tracking and voltages for evaluating differential amplifiers It may be used as a battery eliminator or to power individual circuit boards or cards while removed from the system Its output can be evaluated while powering a breadboard or prototype circuit to determine the circuits power supply requirements Its laboratory quality specifications will meet most engineering laboratory requirements The same features that make the Model 1760 a good choice for an engineering lab also make it a good choice for most other solid state electronic applications These applications include service shops industrial production testing of components assemblies and complete equipment for school laboratories and home use by electronic hobbyists FEATURES TRIPLE OUTPUT Operates as three separate power supplie
30. oltages with a common negative A typical example of this would be a device that uses both TTL 5 V and analog typically 15 V circuitry Using both supplies two differing positive voltages with a common negative are obtained as follows l 2 Select the INDEPendent operating mode and set up the LED displays so that both displays monitor voltage Connect the ground straps between each supplies negative terminal and ground Independently set the desired voltage and maximum current for the A and B supplies using the A VOLTAGE and CURRENT controls and the B VOLTAGE and CURRENT controls respectively Turn off the power supply and the equipment to be powered during hook up Connect the positive polarity inputs of the circuit to be powered to the positive red terminal of the supply Connect the common negative input of the circuit to be powered to either the supply s negative black or ground green terminal If desired set the LED displays to monitor current 36 APPLICATIONS Adjust for Preset current Ad i just for desired desired voltage limit Select INDEP voltage Preset 1781 DC POWER Surp current limit Equipment Being Powered Fig 12 Typical Hook Up Using Two Different Positive Voltages and a Common Negative APPLICATIONS Two Identical Negative Voltages With a Common Positive Refer To Fig 13 When the same negative voltage is required at two poin
31. ositive or negative polarity d If the chassis or common of the equipment being powered is separate from both the positive and negative polarity power inputs use the connection shown in Fig 3D Observe proper polarity If the circuit being powered is not equipped with reverse polarity protection damage to the circuit can result from reverse polarity Use color coded hook up leads for convenience in identifying polarity red for and black for Make sure that the hook up leads offer sufficient current capability and low resistance between the power supply and the circuits being powered OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY r 1761 DC POWER SUPPLY sora Oemar com pi Eguipment Eguipment Being Powered Being Powered Fig 3 Independent Operation Grounding Possibilities 16 OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY 1 1761 DC POWER SUPPLY OS yawa omw rn rosero yanak AU oma ga WYN pm vem Tat rnd rea ens TA Equipment Equipment Being Powered Being Powered Fig 3 Independent Operation Grounding Possibilities 17 Typical Constant Voltage Operation 1 Before connecting the device to be powered to the power supply determine the maximum safe load current for the device to be powered and set the current limit value see Setting Current Limit procedure in this section Set Fine VOLTAGE control to center and Coarse VOLTAGE control to minimum fully coun
32. plies with a 0 30V 0 35V model 1761 volt dc output and a third output with a 4 6 5A 2 6 5A model 1761 volt dc output The main V supplies are adjustable with both coarse and fine voltage controls for precise settability and are capable of current output of 0 2 0 3 model 1761 amps The third supply has a current output of 0 5 amps allowing it to handle extensive digital logic circuitry Two large panel mounted LED meter displays can monitor either the output current or output voltage of each supply The two main volt supplies can be operated independently or in one of two tracking modes In the series tracking mode the B Supply tracks from 5 to 100 of the voltage of the A Supply Maximum current setting of the two supplies can still be set independently when in the series tracking operating mode In the series tracking mode the A and B supplies are connected in series allowing a single output of 0 60 0 70 model 1761 V at up to 2 3 model 1761 amps In the parallel tracking mode the two supplies are connected together in parallel allowing a single 0 30 0 35 model 1761 V output at up to 4 6 model 1761 amps Both main volt supplies may be used in constant voltage or constant current applications The crossover from constant voltage to constant current modes is smooth and automatic LED s indicate the CV constant voltage or CC constant current mode of operation In
33. ply the maximum current and voltage are set using the A controls Using the A supply output jacks follow the instructions for Setting Current Limit INDEPENDENT USE OF A OR B SUPPLY paragraph of this section Remember that the actual current output at the A supply output jacks is double the reading on the B LED Display 26 OPERATING INSTRUCTIONS Adjust the output voltage to the desired level using the A VOLTAGE controls Turn off the power supply and the equipment to be powered during hook up Connect the positive polarity of the device being powered to the red terminal of the A power supply Connect the negative polarity of the device being powered to the black terminal of the A power supply Fig 9 illustrates the grounding possibilities when used in the TRACKing PARallel mode a If the negative polarity of the equipment or circuit being powered is also the chassis or common it may be grounded to earth by strapping the black terminal to the green terminal as shown in Fig 9A b Similarly the positive polarity can be grounded by strapping the red terminal to the green terminal as shown in Fig 9B c If an earth ground reference is not required the configuration of Fig 9C may be used The scheme in Fig 9C should also be used where it is not known whether the chassis is common with either the positive or negative pol
34. rallel or series tracking mode is selected Read the value on the A 4 6 5 V LED Display when the voltage V and master 0 30 V metering modes are selected Fine VOLTAGE Control Fine adjustment of output voltage of the A supply Also functions as fine adjustment control for the maximum output voltage of the B supply when either parallel or series tracking mode is selected Read the value on the A 4 6 5 V LED Display when the voltage V and master 0 30 V metering modes are selected 12 CONTROLS AND INDICATORS 14 CURRENT Control Adjusts current limit of A supply in constant voltage mode Adjusts constant current value of A supply in constant current mode Current can be read from the A 4 6 5V LED Display when the current A and master 0 30V metering modes are selected 15 Terminal Red Positive polarity output terminal for the A supply Also serves as the positive polarity terminal for 4 A parallel and 0 to 60 V series tracking es 16 Terminal Green Earth and Chassis Ground 17 Terminal Black Negative polarity output terminal for the A supply Also serves as the negative polarity terminal for 4 A parallel tracking operation In series tracking operation this terminal is internally tied to the positive terminal of the B supply B SUPPLY CONTROLS AND INDICATORS 18 C V Constant Voltage Indicator Green LED lights when the B
35. rity output terminal for 4 6 5V supply 8 Voltage Level Control Adjusts output voltage for 4 6 5V supply Fully counterclockwise rotation adjusts output voltage to 4V Clockwise rotation increases voltage to a maximum of 6 5V full clockwise rotation 9 5 A OVERload Indicator Lights when load on 4 6 5 Volt supply becomes too large CONTROLS AND INDICATORS 1761 DC POWER SUPPLY INDEF MASV TRACK PAR 245 26 21 29 22 6 7 9 12 777 5 Fig 1 Front Panel Controls and Indicators 11 A SUPPLY CONTROLS AND INDICATORS 10 11 12 13 C C Constant Current Indicator Red LED lights when A supply is in the Constant Current mode The Power Supply regulates the output current at the value set by the A CURRENT control In the Parallel Tracking mode when this indicator is lit both the A and B supplies are in the Constant Current mode C V Constant Voltage Indicator Green LED lights when the A supply is in the Constant Voltage mode The Power Supply regulates the output voltage at the value set by the A VOLTAGE controls In either the Series or Parallel Tracking mode when this indicator is lit both the A and B supplies are in the Constant Voltage mode Coarse VOLTAGE Control Coarse adjustment of the output voltage of the A supply Also functions as coarse adjustment control for the maximum output voltage of the B supply when either pa
36. rmine and correct the cause of the blown fuse then replace only with a fuse of the correct rating as listed in Table 1 The fuse is located on the rear panel see Fig 2 Table 1 Fuse Values OPERATION FUSE VALUE TYPE 120 V 3 0A Slow Blow 220 230 240 V 1 5A Slow Blow 41 LINE VOLTAGE CONVERSION INTERNATIONAL UNITS This power supply can be switched from 110VAC to 220 230 240VAC by a switch located on the rear panel To select the desired line voltage simply insert the fuse and fuse holder so that the appropriate voltage is pointed to by the arrow Be sure to use the proper vale fuse see label on rear panel MAINTENANCE ADJUSTMENTS Table 2 Functions of Calibration Adjustments This unit was accurately adjusted at the factory before ADJ FUNCTION OF ADJ OCATION OF ADJ shipment Readjustment is recommended only if repairs have lt A SUPPLY 5 V REF MAIN BOARD been made in a circuit affecting adjustment accuracy or if you B SUPPLY 5 V REF MAIN BOARD have a reason to believe the unit is out of adjustment However nr adjustments should be attempted only if a 4 1 2 digit Re ne oh AN BOARD multimeter with an accuracy of 0 1 dev or better is available B K Precision Model 391 or equivalent RE na IEE On If readjustment is required use the following procedure All R133 6 5V V METER AIN BOARD references to left and right are correct when facing the front of R134
37. s Each has floating output and is completely isolated from the other two ONE 4 TO 6 5 V 2 to 6 5V model 1761 SUPPLY Durable 0 to 5 amp supply is ideal for use with most digital logic circuitry Adequate current capacity for extensive circuitry TWO 0 30 VOLT 0 35V model 1761 SUPPLIES A and B supply are continuously variable over their respective voltage ranges with coarse and fine controls Each supply has a 2 amp 3 amp model 1761 current capacity UNIQUE TRACKING FEATURE The two 0 to 30V 35V model 1761 supplies can be operated so that the B supply tracks the A supply Outputs can be strapped for two positive voltages with a common negative two negative voltages with a common positive or one positive and one negative with a neutral common SINGLE 0 60V 0 70V model 1761 SUPPLY Series tracking feature allows use of A and B supplies as one 0 to 60V 2 amp 0 70V 3 amp model 1761 supply SINGLE 0 30V 4A 0 35V 5A model 1761 SUPPLY Parallel tracking feature allows use of A and B supply as a 0 to 30 0 35V model 1761 V supply with a 4 amp 6 amp model 1761 current capacity through A output terminals CONSTANT VOLTAGE OR CONSTANT CURRENT The A and B supplies provide regulated dc voltage output or regulated dc current output Crossover is smooth and automatic LED DISPLAY Two large easy to read LED 4 digit displays monitor output voltage or output c
38. supplies only when they are used independently from one another When used in the INDEPendent operating mode the operating controls of the two power supplies are completely independent and either supply can be used individually or both can be used simultaneously Basic operation is covered here Several variations are covered in the APPLICATIONS section of this manual 14 Hook up 1 2 Disengage the INDEP TRACK mode switch so that the power supply is in the INDEPendent operating mode Turn off the power supply and the equipment to be powered during hook up Connect the positive polarity of the device being powered to the red terminal of the power supply Connect the negative polarity of the device being powered to the black terminal of the power supply Fig 3 illustrates the grounding possibilities when used in the INDEPendent mode a If the negative polarity of the equipment or circuit being powered is also the chassis or common it may be grounded to earth by strapping the black terminal to the green terminal as shown in Fig 3A 15 OPERATING INSTRUCTIONS b Similarly the positive polarity can be grounded by strapping the red terminal to the green terminal as shown in Fig 3B c If an earth ground reference is not required the configuration of Fig 3C may be used The scheme in Fig 3C should also be used where it is not known whether the chassis is common with either the p
39. supply to either slowly increase or decrease with the change in the power supply s internal temperature As the power supply outputs more power its internal temperature will increase causing the metering primarily the current to slowly increase As the power demand is deceased the power supply will cool causing the metering primarily the current to slowly decrease If the power supply remains with a constant output of power for more than fifteen minutes the power supply metering will remain constant and should not continue to drift CONTROLS AND INDICATORS GENERAL CONTROLS AND INDICATORS 1 POWER Switch Turns power on and off 2 TRACKING Mode Switches Two pushbutton switches that select INDEPendent mode SERies tracking mode or PARallel tracking mode as follows a When INDEP TRACK switch is disengaged out the unit is in the INDEPendent mode and the A and B power supplies are completely independent from one another b When the INDEP TRACK switch is engaged in and the SER PAR switch is disengaged out the unit is in the TRACKing SERies mode In this mode maximum voltage of both supplies is set using the A VOLTAGE controls voltage at output terminals of the B supply tracks the voltage at the output terminals of the A supply Also in this mode of operation the positive terminal red of the B supply is internally connected to the negative terminal black of the A supply This allows t
40. tact name phone number and description of problem 46 Limited Two Year Warranty B amp K Precision Corp warrants to the original purchaser that its products and the component parts thereof will be free from defects in workmanship and materials for a period of two years from date of purchase B amp K Precision Corp will without charge repair or replace at its option defective product or component parts Returned product must be accompanied by proof of the purchase date in the form of a sales receipt To obtain warranty coverage in the U S A this product must be registered by completing a warranty registration form online at www bkprecision com within fifteen 15 days of purchase Exclusions This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs The warranty is void if the serial number is altered defaced or removed B amp K Precision Corp shall not be liable for any consequential damages including without limitation damages resulting from loss of use Some states do not allow limitations of incidental or consequential damages So the above limitation or exclusion may not apply to you This warranty gives you specific rights and you may have other rights which vary from state to state B amp K Precision Corp 22820 Savi Ranch Parkway Yorba Linda CA 92887 www bkprecision com 714 921 9095 Model Number Date Purchased 47 TEST INSTRUMENT SA
41. terclockwise Turn off power supply and connect it to the device to be powered see Hook Up procedure in this section Turn on POWER switch The CV indicator should light Set the meter selection switch to the V position to select the voltage metering mode Increase the VOLTAGE setting until the LED display reads the desired value The Fine control permits easier setting to a specific value Set the meter selection switch to the A position to select the current metering mode and note the load current on the display If the load current exceeds the preset current limit the CV indicator will go off and the CC indicator will light In this case the power supply automatically switches to the constant current mode and further rotation of the VOLTAGE control will not increase the output voltage 18 OPERATING INSTRUCTIONS Read output voltage and current from display CV indicator on 1761 DC POWER SUPPLY Select V out Preset Adjust to current desired voltage limit Fig 4 Typical Constant Voltage Operation OPERATING INSTRUCTIONS Setting Current Limit Adjust to desired i i 1 i Read current limit current 1 Determine the maximum safe current for the device to be Midrange value from display limit powered 2 Temporarily short the and terminals of the power supply together with a test lead 3 Rotate the Coarse VOLTAGE control away from zero sufficiently for the CC indicator to
42. that the hook up leads offer sufficient current capability and low resistance between the power supply and the circuits being powered 10 amp hook up leads are available as an optional accessory 4 Set the Right V A switch to the A position to monitor the load current OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY 1761 DC POWER SUPPLY Eguipment Eguipment Being Powered Being Powered Fig 10 Grounding Possibilities for 4 6 5 V Power Supply 30 OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY 1761 DC POWER SUPPLY Equipment Equipment Being Powered Being Powered Fig 10 Grounding Possibilities for 4 6 5 V Power Supply 31 OPERATING INSTRUCTIONS 10 If the red OVERIoad indicator lights too much load has been placed NOTE on the supply This will cause voltage and current to drop and prevent proper operation of the 4 6 5V supply To correct this If decreasing the load does not cause situation the load on the supply must be decreased so that no more the overload indicator to turn off the than 5 amps of current are required overvoltage protection circuitry has activated In order to return the supply to normal operation the output voltage must be decreased or the external voltage source must be re moved and the power must be momentarily shut off 32 APPLICATIONS GENERAL The Model 1760A 1761 power supply has a very wide variety of applications in electrical and electronics servicing engineering labor
43. the power supply and the equipment to be powered Being Powered during hook up A 5 Connect the positive polarity input of the circuit to be powered to the positive red terminal of the A supply and connect the negative polarity of the circuit to the negative terminal of the B supply Connect the circuit ground to the ground terminal of the A supply the positive terminal of the B supply or the GND green terminal Fig 15 Typical Hook Up Using Identical Positive and Negative Voltages with a Separate Common 39 Differing Positive and Negative Voltages With a Separate Common Refer To Fig 16 Using both supplies and the series tracking mode of operation different positive and negative voltages with a separate common utilizing the variable B tracks A mode of operation are obtained as follows l 2 Select the TRACKing SERies operating mode and set up the LED displays to monitor voltage Connect one ground strap between the ground terminal and the negative terminal of the A supply and the other between the ground terminal and the positive terminal of the B supply Set the desired voltage for each supply using the VOLTAGE controls Set the maximum current using the CURRENT controls Turn off the power supply and the equipment to be powered during hook up Connect the positive polarity input of the circuit to be powered to the positive red terminal of the
44. the power supply output is connected to an exter nal high voltage Some equipment being powered may contain high voltage and present a shock hazard Observe caution If the power supply output is floated referenced to a voltage rather than earth ground turn off the power supply and the equipment under test when making connec tions Never float the power supply to a potential greater than 100 volts peak with respect to earth ground EQUIPMENT PRECAUTIONS Avoid using the power supply in ambient temperatures above 40 C Always allow sufficient air space around the heat sink at the rear of the power supply for effective radiation to prevent internal heat build up Although the power supply is protected against reverse polarity damage the circuit being powered may not include such protection Always carefully observe polarity incorrect polarity may damage the equipment under test Do not exceed the voltage rating of the circuit being powered Many transistors and integrated circuits will not withstand voltage of 30 volts There is no need to worry about voltage spikes or overshoot damaging the equipment under test The voltage between the output terminals of the power supply never exceeds the preset value as the POWER switch is turned on or off INDEPENDENT USE OF A OR B SUPPLY The A and B supplies each provide a 0 to 30 volt output at up to 2 0 amps This procedure covers the use of the A and B
45. to the battery manufacturer s charging specifications for proper voltage and current settings 34 APPLICATIONS Charging information is sometimes printed on the batteries Battery charging at least initially requires the constant current mode of operation Before connecting the power supply to the battery preset the VOLTAGE controls to the fully charged terminal voltage specified by the battery manufacturer Turn off the power supply while connecting the battery Observe proper polarity and connect as for constant current operation Adjust the CURRENT control for the maximum charging current specified by the battery manufacturer If the maximum charging current is greater than the power supply s maximum load current set the CURRENT control to maximum The CC indicator will light and the battery will charge at the preset current limit As the battery approaches full charge its terminal voltage will approach that of the power supply output and the charging current will taper off The power supply may automatically switch to CV constant voltage operation When this occurs the power supply will continue to provide a trickle charge SPLIT SUPPLY Frequently split power supplies are required for amplifier and other electronic circuits The Model 1760 is ideally suited for split power supply operation This supply can be configured to provide two positive voltages with a common negative two negative voltages with a commo
46. tronics Servicing 33 Electronics Manufacturing 33 Electronics Design Lab 34 Electronics Education 34 Battery Charging 34 Split 80 1 34 MAINTENANCE 4 Fuse Replacement 4 Line Voltage Conversion 41 Adjustments 42 A Supply and A Metering Adjustments 42 4 6 5 V Supply and 4 6 5 V Metering Adjustments 44 B Supply and Metering Adjustments 44 B Series Tracking Adjustment 45 Instrument Repair Service 45 WARRANTY SERVICE INSTRUCTIONS 46 LIMITED TWO YEAR WARRANTY 47 SPANISH MANUAL 50 INTRODUCTION These B K Precision Triple Output DC Power Supplies are high quality general purpose dc power sources They provide two main sup
47. ts in the same circuit and a common positive is needed perform the following 1 Connect the ground strap between the positive terminal and the ground of the A supply 2 Set the desired voltage and maximum current using the A VOLTAGE and CURRENT controls 3 Turn off the power supply and the equipment to be powered during hook up 4 Connect the negative polarity inputs of the circuit to be powered to the negative black terminals of the supplies Connect the common positive input of the circuit to be powered to the A supply s positive red or ground green terminal Preset Select TRACKING i PARALLEL Adjust for desired current voltage limit Equipment Being Powered Fig 13 Typical Hook Up Using Two Identical Negative Voltages and a Common Positive 37 Two Differing Negative Voltages With a Positive Common Refer To Fig 14 Using both supplies two differing negative voltages with a common positive are obtained as follows l 2 Select the INDEPendent operating mode and set up the LED displays so that both displays monitor voltage Connect the ground straps between each supplies positive terminal and ground Independently set the desired voltage and maximum current for the A and B supplies using the A VOLTAGE and CURRENT controls and the B VOLTAGE and CURRENT controls respectively Turn off the power supply and the equipment to be powered dur
48. ua pN Equipment Equipment Being Powered Being Powered Fig 8 Series Tracking 0 to 60V Operation Grounding Possibilities 24 OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY wara a 7 YN DIA CO ed e s A werner A 5 L Bok Equipment Being Powered Fig 8 Series Tracking 0 to 60V Operation Grounding Possibilities 25 a Similarly the positive polarity can be grounded by strapping the red terminal of the A supply to the green terminal of the A supply as shown in Fig 8B b If split supply operation is desired a positive and negative voltage with a center ground can be achieved by strapping the black terminal of the A supply to the green of the A supply as shown in Fig 8C See the APPLICATIONS section of this manual for more information on split supply operation NOTE If one of the supplied ground straps is to be used only use it in one of these three ways Connecting two ground straps could ground both the positive and negative terminals and load down the power supply causing improper operation c If an earth ground reference is not required the configuration of Fig 8D may be used The scheme in Fig 8D should also be used where it is not known whether the chassis is common with either the positive or negative polarity d If the chassis or common of the equipment being powered is separate from both the positive and
49. ully clockwise position The maximum current is set using the A CURRENT control Follow the instructions for Setting Current Limit INDEPENDENT USE OF A OR B SUPPLY section of this manual using the A CURRENT control Adjust the output voltage to the desired level using the A VOLTAGE controls remember that the actual output voltage is double the reading on the B LED Display Turn off the power supply and the equipment to be powered during hook up Connect the positive polarity of the device being powered to the red terminal of the A power supply Connect the negative polarity of the device being powered to the black terminal of the B power supply Fig 8 illustrates the grounding possibilities when the unit is used as a 0 to 60 volt supply a If the negative polarity of the equipment or circuit being powered is also the chassis or common it may be grounded to earth by strapping the black terminal of the B supply to the green terminal of the B supply as shown in Fig 8A OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY 1 1761 DC POWER SUPPLY FUNCIIDA wrn cym ree io em A mus ms da ss Equipment Being Powered Fig 8 Series Tracking 0 to 60V Operation Grounding Possibilities 23 OPERATING INSTRUCTIONS 1761 DC POWER SUPPLY 1 1761 DC POWER SUPPLY NWYN mana 7 a Tur KANAN enam ga sore en cu wa ro
50. urrent of all three supplies Use of two meters allows simultaneous current and voltage metering when using A and B supplies in tracking operation Good visibility in bright or low light LABORATORY QUALITY Excellent regulation low ripple PRE REGULATOR Limits internal dissipation for higher reliability and efficiency ISOLATED OUTPUT Either polarity may be floated or grounded OVERLOAD PROTECTION Fully adjustable current limiting from 5 to 100 of maximum output current for A and B supplies protects circuit under test and the power supply REVERSE POLARITY PROTECTION Prevents damage to power supply from external voltage of reverse polarity A AND B SUPPLIES Output Voltage Range OV to 30V OV to 35V model 1761 Output Current Limit Range 0 1A 5 to 2A 3A model 1761 100 Load Regulation Constant Voltage lt 0 01 3 mV Line Regulation 108 132 V Constant Voltage lt 0 01 3 mV Ripple Constant Voltage Sl mV RMS Recovery Time Constant Voltage lt 100 S Temp Coefficient Constant Voltage lt 300 ppm C Load Regulation Constant Current lt 0 2 3mA Line Regulation 108 132 V Constant Current lt 0 2 3mA Ripple Current at 108 V for Constant Current lt 3mA RMS Tracking Series Accuracy 0 2 10mV SPECIFICATIONS Tracking Series B tracks A 5 to 100 Panel Meter Accuracy Volts 0 5
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