Download
Share
Print this page
BK Precision 1790 Operation & Maintenance Manual
  1. Manuals
  2. Brands
  3. BK Precision Manuals
  4. Power Supply
  5. 1790
  6. Operation & maintenance manual
BK Precision 1790 Operation & Maintenance Manual

BK Precision 1790 Operation & Maintenance Manual

High current power supply
Hide thumbs Also See for 1790:

Advertisement

Quick Links

Download this manual
B PRECISION
K
®
OPERATION &
MAINTENANCE MANUAL
Model 1790 High Current Power Supply

Advertisement

loading
Need help?

Need help?

Do you have a question about the 1790 and is the answer not in the manual?

Questions and answers

Related Manuals for BK Precision 1790

Summary of Contents for BK Precision 1790

  • Page 1 B PRECISION ® OPERATION & MAINTENANCE MANUAL Model 1790 High Current Power Supply...
  • Page 2 Limited Two Year Warranty B & K Precision Corp. warrants to the original purchaser that its product and the component parts therof, will be free from defects in workmanship and materials for a period of two years from the data of purchase. B &...
  • Page 3 OPERATORS SAFETY SUMMARY The general safety information in this part of the summary is for both operating & servicing personnel. Specific warnings and cautions will be found throughout the manual where they apply, but may not appear in this summary. TERMS IN THIS MANUAL CAUTION : Statements identify conditions or practices that could result in damage to...
  • Page 4 TABLE OF CONTENTS SECTION PARTICULARS PAGE NO. GENERAL INFORMATION SPECIFICATIONS INSTALLATION OPERATING INSTRUCTIONS TESTING & CALIBRATION PROCEDURE SERVICE INSTRUCTION PART LIST SCHEMATICS CIRCUIT DIAGRAMS...
  • Page 5 GENERAL INFORMATION DESCRIPTION : The 1790 (349) High Current Regulated D.C. Power Supply is completely solid and suitable for bench operation or standard 19" rack operation. It is a well regulated constant voltage / constant current supply which delivers 0-32V at 0-20Amps and can be adjusted continuously throughout the output range.
  • Page 6 SECTION - 2 SPECIFICATIONS OUTPUT VOLTAGE 0-32V DC continuously variable with coarse and fine voltage controls. LOAD CURRENT 0-20 Amp max., continuously variable with coarse and fine controls. CONSTANT VOLTAGE MODE REGULATION LINE Less than ± 0.01% ± 2mV for ±10% change in line voltage.
  • Page 7 SECTION - 3 INSTALLATION INITIAL INSPECTION : As soon as the power supply 1790 (349) unit is unpacked, inspect for any damage that may have occurred during transit. Save all packing material until inspection is completed. If any damage is found, notify the carriers immediately.
  • Page 8 230V Mains Operation at the Input of EMI Filter located at bottom side of the unit. REPACKAGING FOR SHIPMENT : To ensure safe shipment of the power supply 1790 (349) unit, it is recommended that the package designed for the unit be used. The original packaging material is reusable.
  • Page 9 Output On/OFF Switch Voltage Coarse Control CV Mode Indication Output Terminals Voltage Fine Control Current DPM Remote Sense Switch Voltage DPM CC Mode Indication Remote Sense Terminal Current Coarse Control Output Preset Switch Earth Terminal 1790 : FRONT PANEL LAYOUT...
  • Page 10 BACK PANEL LAYOUT INPUT 115/230VAC FUSE TYPE F16A/8A COM PROG 1) INPUT FUSE HOLDER. 3) INT / EXT PROGRAM TERMINAL. 5) VENTILATION.. 2) MAINS CORD. 4) PROTECTIVE GROUND.
  • Page 11 SECTION - 4 OPERATING INSTRUCTIONS TURN ON SETTING PROCEDURE : following procedure describes the use of controls and indicators for Constant Voltage and Constant Current Mode of Operation. CONSTANT VOLTAGE (CV) MODE : a. Set ‘POWER ON’ Switch & keep the OUTPUT ON/OFF switch to OFF position ( b.
  • Page 12 4.3.1 Load Wiring When connecting load wiring to the power supply you consider the following factors. * The current carrying capacity of the wire, and * The noise and impedance effects of the load lines. 4.3.2 Current Carrying Capacity As a minimum load wiring must have a current capacity greater than the output rating of the power supply.
  • Page 13 CONNECTING MULTIPLE LOADS LOAD LINES USE THE LARGEST GAUGE AND SHORTEST LANGHT POSSIBLE POWER SUPPLY LOAD-1 POSITIVE LOAD POSITIVE OUTPUT TERMINAL TERMINAL NEGATIVE LOAD OUTPUT RETURN TERMINAL TERMINAL LOAD-2 POSITIVE LOAD LOAD LINES TERMINAL USE THE LARGEST GAUGE AND SHORTEST NEGATIVE LOAD LANGHT POSSIBLE TERMINAL...
  • Page 14 Positive or negative voltage can be obtained from this supply by grounding either one of the output terminals or one end of the load. Always use two leads to connect load to the supply, regardless of where the setup is grounded. This will eliminate any possibility of the output current return paths through the power source ground which would damage the line cord plug.
  • Page 15 OUTPUT CAPACITANCE : Internal capacitor C3 ( L1791-FP-CNT-1203 PCB ) connected across the output terminals of the power supply, helps to supply high current pulses of short duration during constant voltage operation. Any capacitance added externally will improve the pulse current capability, but will decrease the safety provided by the constant current circuit.
  • Page 16 Ref. Supply Comp arator V Ref Aux. Bias Supply Switch Short Circuit Protection Current Control Power Shunt Rect. Series M ains IN Pre Reg. +O ut & Regulator Filter Current Sam pling Resistor Pre Reg. Driver Comp arator Control V Ref Turn O n Control Voltage...
  • Page 17 WIRING CONNECTOR DETAILS ( PCB : L1791-FP-CNT-1203B ) CONN PIN NO. DETAILS OF CONNECTIONS PINK V/A DPM PCB J3, PIN NO. 4, JUP WITH J2 PIN NO. 10 (PS-AUX-DC PCB). WHITE GOES TO V DPM J3, PIN NO. 2. YELLOW GOES TO PS-AUX-DC-1791-0903A, J2 PIN NO.
  • Page 18 Bridge Tx 1 Tx 2 Blue Blue Module White White Primary R F I CON 102 115V Orange ange As per the 220K Main requirement Green Green Green Board Primary 115V Brown Brown .1µF Auxillary Main 275V Black Transformer Transformer Black Orange Capacitor...
  • Page 19 Adjust the Voltage knobs to 32V. Load Output to rated current 20A in case of 1790. Ensure CV LED Glows to indicate CV Mode. b. Keep the unit in full load condition (32V, 20A). Connect the Output of Power Supply to true RMS AC Voltmeter to check ripple.
  • Page 20 Output of Power Supply to true RMS AC Voltmeter and note down AC Voltage ( in millivolts ). The Output CC Ripple is calculated as ratio of measured AC Voltage ( in mV ) to Load Resistance (32V/20A, 1.6E) in case of 1790. The CC Ripple should be less than 6mA.
  • Page 21 SECTION - 6 SERVICE INSTRUCTION GENERAL : The instrument has been tested throughly and then released for dispatch. Normally, the unit works satisfactorily under all condition. However due to ageing / misuse or malfunctioning, the unit may become defective. In case, the user wants to carryout Servicing, the following instructions will be helpful in rectifying the defects The Servicing shall be done only by Qualified personnel.
  • Page 22 available, use a dynamic tester. Static-type testers are not recommended, since they do not check operation under simulated operating conditions. An approved anti-static suction-type desoldering tool must be used to remove soldered-in transistors. Integrated circuits can be checked with a voltmeter, test oscilloscope, or by direct substitution.
  • Page 23 6.3.6 If Fuse blows, connect the unit through a variable AC Source with a current meter and monitor the current at no load. If the current is very high (more than 2 ampere or so ) load, check for Bridge Rectifier short or shorted Diode, or Secondary Winding short, etc 6.3.7 If output voltage or current DPM's are not reading, check for loose connections...
  • Page 24 6.4.3 VOLTAGES AT VARIOUS PINS OF IC LM324 IS AS FOLLOWS ( IC-101 ) IC PIN NO. VOLTAGES & CHECK CONDITIONS PIN1 0V ( WHEN V POT KEPT AT MIN. POSITION IN CV MODE ) PIN1 +5V ( WHEN V POT KEPT AT MAX. POSITION IN CV MODE ) PIN2 &...
  • Page 25 6.5.2 ORDERING PROCEDURE : When ordering replacement parts from B+K Inc. please include the following minimum information : 1. Power Supply Type ( 1790 B+K ), Model Code : 349. 2. Power Supply Serial Number ( For example, 05080001 ).
  • Page 26 CAUTION Static discharge can damage any semiconductor component in this instrument. This instrument contains electrical components that are susceptible to damage from static discharge. Static voltages of 1KV to 30KV are common in unprotected environments. Observe the following precautions to avoid damage : Minimize handling of static-sensitive components.
  • Page 27 FAULT FINDING PROCEDURE ( A ) FUSE BLOWS FUSE BLOWS Is Line Voltage OK ? Adjust Proper Line Voltage. Is Fuse Rating OK ? Insert proper rating Fuse. Is Mains Transformer Tapping OK ? Adjsut the Tap according to required voltage. Are Power Diodes Connected on Heat Sink Short ? Replace the Damaged Diodes.
  • Page 28 ( B ) UNREGULATED O/P VOLTAGE UNREGULATED O/P VOLTAGE Is IC LM324 OK ? Replace the IC. Is Voltage Pot Open OR Replace the Voltage Pot and Pot Wire is Reaching PCB ? Ensure proper continuity with the PCB Are Mosfets OK ? Replace the Damaged Mosfet.
  • Page 29 ( C ) NO OUTPUT VOLTAGE. NO O/P VOLTAGE Is IC LM324 OK ? Replace It. Is Voltage Pot Short ? Replace It. Is Voltage Selection Preset Open ? Replace It. Are Zener Diodes Z1 & Z2, Preset VR1 on Preg. PCB OK ? Replace It.
  • Page 30 ( D ) NO DPM INDICATION. NO DPM INDICATION Is Display Completely Blank ? Is Continuity between IC7805 & DPM OK ? Does Display shows only Ensure proper Continuity. dot Indication ? Is Continuity between IC7905 & Ensure proper Continuity. DPM's OK ? Is Continuity between ANGD &...
  • Page 31 ( E ) DPM NOT READ ( 000 ). DPM NOT READ ( V & I ) ( 000 ) Is DPM IC 707 OK ? Replace It. Does Hi and Low Wire Ensure proper Continuity. Reach DPM's ? IC TL431 OK ? Replace It.
  • Page 32 ( F ) UNIT NOT TAKE CURRENT. UNIT NOT TAKE CURRENT Is Current Set Preset R21 OK ? Replace It. Is Current Pot Short ? Replace It. Is Wiring Related to Ensure proper Continuity. Current Pot OK ? Are Load Terminals connected properly with Nut inside Unit ? Ensure proper Terminal Contact.
  • Page 33 ( G ) UNIT DIRECTLY GOES TO CC. UNIT DIRECTLY GOES TO CC Is Shunt Resistor open OR Replace Shunt Resistor Dry Soldered ? if necessary. Is IC LM324 OK ? Replace It. Is Current select Preset Replace It. R21 Open ? Is Remote Sense Terminal Pressed ? Ensure Remote Sense Switch is...
  • Page 34 ( H ) NO CURRENT CONTROL. NO CURRENT CONTROL Is Current Pot Open ? Replace it. Are Wires related to Current Pot OK ? Ensure proper Connectivity. 1. Check the Current Potentiometer. It might be Open. 2. Check all Wires related to Current Potentiometer. ( I ) POOR LINE REGULATION.
  • Page 35 ( J ) POOR LOAD REGULATION. POOR LOAD REGULATION Load Terminal Nut inside Unit might be Loose. Is there any Oscillation Reduce Resistor R6 ( 2.2K ) on in CV Mode ? F/Panel PCB until Oscillation dies OUT. If Oscillation still Prevail reduce R9 to 2K on F/Panel PCB.
  • Page 36 ( L ) EXTERNAL PROGRAMMING NOT OK. EXTERNAL PROGRAMMING NOT OK Is Pot connected across INT Ensure 5K Pot connected & COM OK ? between INT and COM Terminal. Is there proper Continuity between PROG Terminal and O/P +Ve ? Ensure proper Connectivity.
  • Page 37 SECTION - 7 PART LIST & SCHEMATICS L1791-FP-CNT-1203 PCB ASSY Reference Part Reference Part Designator Description Designation Description RESISTORS 500E(3206F) Not Used 100E 3.3K 100E(3206F) 2.2K Not Used 100E(3206F) 560E 820E 100E(3206F) Not Used 1K, 10W 100K Short 1.5K 3.3E Short 100E 330K...
  • Page 38 L1791-FP-CNT-1203 PCB ASSY Reference Part Reference Part Designator Description Designation Description CONNECTORS J2.54 - 3MSL, 3 PIN SIL 2.54mm ST LOCK MALE J2.54 - 3FSL, 3 PIN SIL 2.54mm ST LOCK FEMALE CLAMPS SINGLE PUSH SWITCH MTG. CLAMP DOUBLE PUSH SWITCH MTG. CLAMP DOUBLE PUSH SWITCH MTG.
  • Page 39 PS-PREG-1791-0903 PCB ASSLY Reference Part Reference Part Designator Description Designation Description TRANSISTORS BC 109 BC 557 MPSA12 BC 547 BC 557 ZENERS 4.7V, ½W 10V, ½W PRESET 5K ( 3206F ) HOR TRANSFORMER EE25 PULSE TX. Z-DPM/01 REV - 01 X 2 Reference Part Reference...
  • Page 40 PS-AUX-DC-L1791-0903 PCB ASSLY Reference Part Reference Part Designator Description Designation Description CAPACITORS 470µF/35V, ELE 100nF, 50V, DISC 47µF/35V, ELE 470µF, 35V, ELE 10µF/35V, ELE 470µF, 35V, ELE 10µF/35V, ELE 220µF, 35V, ELE 100nF/50V, DISC 100nF, 50V, DISC Not Used 100nF, 50V, DISC Not Used 10µF, 35V, ELE LM 78T12...
  • Page 41 FRONT PANEL ASSLY Reference Part Reference Part Designator Description Designation Description 5K, WWPOT 500E, WWPOT 1K, WWPOT 50E, WWPOT SWITCH 16A/250V ON/OFF SWITCH MAIN CHASSIS ASSLY Reference Part Designator Description RESISTOR 4.7K/2W, MOR 0.025E / 25W SHUNT DIODES U30D40C (30AMP/400V DUAL DIODE) CAPACITORS 6 X 15,000µF, ELE 1µF / 250V AC CAP X 2...
  • Page 44 FRONT PANEL CONTROL PCB OF 1790 / 1791...
  • Page 45 POWER MODULE PCB OF 1790 / 1791...
  • Page 46 PRE REGULATOR / AUX. P/S PCBs 1790 / 1791...
  • Page 47 Service Information Warranty Service : Please return the product in the original packaging with proof of purchase to the below address. Clearly state in writing the perfor- mance problem and return any leads, connectors and accessories that you are using with the device. Non-Warranty Service : Please return the product in the priginal packag- ing to the below address.
  • Page 48 B PRECISION ® B & K PRECISION CORP. SN: 480-808-9-001 22820 Savi Ranch Parkway Printed in India Yorba Linda, CA 92887 (M-00198) www.bkprecision.com...