B&K 1794 manuale d’uso

Instruction Manual Model 1794 High Current Po wer Supply B PRECISION K [...]

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 & K Precision Corp. will, without charge, repair or replace, at its' option, defective product [...]

TABLE OF CONTENTS SECTION PARTICULARS PA GE NO. 1 GENERAL INFORM ATION 1 2 SPECIFIC ATIONS 2 3 INS TALLATION 3 4 OPER ATING INSTRUCTIONS 5 5 SERVICE INSTRUCTIONS 10 6 PART LIST 16 7 SCHEM ATICS 21 8 CIRCUIT DIAGRAMS 28[...]

1 SECTION - 1 GENERAL INFORM ATION 1.1 DESCRIPTION : The 1794 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 ran[...]

SECTION - 2 SPECIFIC ATIONS OUTPUT VO LT AGE : 0-32V DC continuously variable with coarse and fine voltage controls. LOAD CURRENT : 0-30 Amp max., continuously variable with coarse and fine controls. CONS TA NT VO LT AGE MODE REGUL ATION LINE : Less than ± 0.01% ± 2mV for ±10% change in line voltage. LOAD : Less than ± 0.01% ± 2mV for load cha[...]

SECTION - 3 INS TA LL ATION 3.1 INITIAL INSPECTION : As soon as the power supply 1794 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 immediatel y . Our authorised representatives should also be notified. 3.2 PHYSICAL[...]

3.8 INPUT TAP SELECTION FOR 230V OPER ATION : In case of 230V Mains operation please ensure that shorting links on the Tap Selector board is changed to 230 V , marked on the PCB for both Mains Transformer & Auxilary Transforme r. as per the following diagram. TAP SELECTOR BOARD Please make sure the input varistor is replaced by 20D 361K or equi[...]

SECTION - 4 OPER ATING INSTRUCTIONS 4.1 TURN ON SETTING PROCEDURE : The following procedure describes the use of controls and indicators for Constant Voltage and Constant Current Mode of Operation. CONS TA NT VO LT AGE (CV) MODE : a. Set ‘PO WER ON’ Switch & keep the OUTPUT ON/OFF switch to OFF position ( ). b. Press LIMIT switch and adjust[...]

4.4 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 suppl y , 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 [...]

4.6 OUTPUT CA PA CI TA NCE : Internal capacitor C3 ( L1791-FP-CNT-0603 PCB ) connected across the output terminals of the power suppl y , helps to supply high current pulses of short duration during constant voltage operation. Any capacitance added externally will improve the pulse current capabilit y , but will decrease the safety provided by the [...]

OPER AT ORS 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 appl y , but may not appear in this summar y. TERMS IN THIS MANUAL : CAUTION : Statements identify conditions or practices that could res[...]

USE THE PROPER FUSE : To avoid fire hazard, use only fuse of the correct type, voltage rating and current rating as specified in the parts list for your product. For 115V operation 20A, For 230V operation 10 A Slow blo w. Refer fuse replacement to qualified service personnel. DO NOT OPER ATE IN EXPLOSIVE ATMOSPHERES : To avoid explosion, do not ope[...]

SECTION - 5 SERVICE INSTRUCTION 5.1 GENERAL : The instrument has been tested throughly and then released for dispatch.Normall y, 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[...]

checked by substituting a new component for it ( or one which has been checked previously). Howeve r, be sure that circuit conditions are not such that a replacement transistor might also be damaged. If substitute transistors are not available, use a dynamic teste r. Static-type testers are not recommended, since they do not check operation under s[...]

5.3.6 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 W inding short, etc 5.3.7 If output voltage or current DPM's are not reading, check for loose c[...]

5.4.3 VO LT AGES AT VARIOUS PINS OF IC LM324 IS AS FOLLOWS ( IC-101 ) :- IC PIN NO. VO LT AGES & 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 & 3-- +4.9V AT V POT MAX. POSITION. PIN4 -- +12V ALL CONDITION PIN7 -- 0V AT CC POT MIN. POSITION. PIN7 [...]

your area. Before you purchase check the electrical parts list for the proper value rating, tolerance and description. 5.5.2 ORDERING PROCEDURE : When ordering replacement parts from B+K Inc. please include the following minimum information : 1. Power Supply Type ( 1794 ). 2. Power Supply Serial Number ( For example, 03080001 ). 3. A description of[...]

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 : 1. Minimize handling of static-sensitive c[...]

FA ULT FINDING PROCEDURE ( A ) FUSE BLOWS FUSE BLO WS 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. Is Remote Sense Switch Pressed Release the R[...]

( B ) UNREGUL ATED O/P VOLTAGE UNREGUL ATED O/P VO LT AGE Is IC LM324 OK ? Replace the IC. Is Voltage Pot Open OR Replace the Voltage Pot and Pot W ire is Reaching PCB ? Ensure proper continuity with the PCB Are Mosfets OK ? Replace the Damaged Mosfet. Is Gate W ire of Mosfet Ensure proper continuity of Reaching PCB ? Gate W ire and PCB. Are Diodes[...]

( C ) NO OUTPUT VO LT AGE. NO O/P VO LT AGE 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. Are all the Auxillary W inding Ensure their proper Reaching PCB ? Connectivity with PCB. Is there proper contact of Load Ens[...]

( D ) NO DPM INDIC ATION. NO DPM INDIC ATION Is Display Completely Blank ? Is Continuity between IC7805 & DPM OK ? Does Display shows only Ensure proper Continuit y. dot Indication ? Is Continuity between IC7905 & Ensure proper Continuit y. DPM's OK ? Is Continuity between ANGD & DPM's OK ? Ensure proper Continuit y. Is DPM IC[...]

( E ) DPM NOT READ ( 000 ). DPM NOT READ ( V & I ) ( 000 ) Is DPM IC 707 OK ? Replace It. Does Hi and Low W ire Ensure proper Continuit y. Reach DPM's ? IC TL431 OK ? Replace It. Is minimum Resistance of Pot High ? Replace Pot. 1. Check whether Voltage Hi and Voltage Low W ire is reaching DPM. 2. Check DPM IC 7107. It might be Damaged. 3. [...]

( F ) UNIT NOT TA KE CURREN T. UNIT NOT TAKE CURRENT Is Current Set Preset R21 OK ? Replace It. Is Current Pot Short ? Replace It. Is W iring Related to Ensure proper Continuit y. Current Pot OK ? Are Load Terminals connected properly with Nut inside Unit ? Ensure proper Terminal Contact. 1. Check Current set Preset R21. It might be open. 2. No Con[...]

( G ) UNIT DIRECT LY GOES TO CC. UNIT DIRECT LY GOES TO CC Is Shunt Resistor open OR Replace Shunt Resistor Dry Soldered ? if necessar y. Is IC LM324 OK ? Replace It. Is Current select Preset Replace It. R21 Open ? Is Remote Sense Terminal Pressed ? Ensure Remote Sense Switch is Unpressed in Normal Condition. 1. Check the Shunt Resistor ( 0.025E / [...]

( H ) NO CURRENT CONTROL. NO CURRENT CONTROL Is Current Pot Open ? Replace it. Are W ires related to Current Pot OK ? Ensure proper Connectivit y. 1. Check the Current Potentiomete r. It might be Open. 2. Check all W ires related to Current Potentiomete r. Y N Y ( I ) POOR LINE REGUL ATION. POOR LINE REGUL ATION Improper Device Drop Setting. Keep t[...]

( J ) POOR LOAD REGUL ATION. POOR LOAD REGUL ATION 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 OU T . If Oscillation still Prevail reduce R9 to 2K on F/Panel PCB. Is Capacitor C4 and C2 Leaky ? Replace It. 1. Load Terminal might be Loose. Ensur[...]

( 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 Connectivit y. 1. Check whether 5K Pot is connected between INT and COM Terminal. 2. Check whether there is prop[...]

SECTION - 6 PA RT LIST & SCHEM ATICS 1. L1791-FP-CNT-0603 PCB ASSY Reference Part Reference Part Designator Description Designation Description RESISTORS R1 1K R22 500E(3206F) R2 Not Used R23 33K R3 100E R24 10K R4 3.3K R25 10K R5 1K R26 100E(3206F) R6 2.2K R27 Not Used R7 4K7 R28 100E(3206F) R8 6K8 R29 1K R9 6K8 R30 560E R10 15K R31 820E R11 1[...]

1. L1791-FP-CNT-0603 PCB ASSY Reference Part Reference Part Designator Description Designation Description CONNECTORS J1 J2.54 - 3MSL, 3 PIN SIL 2.54mm ST LOCK MALE J1 J2.54 - 3FSL, 3 PIN SIL 2.54mm ST LOCK FEMALE CL AMPS SW1 SINGLE PUSH S W ITCH MTG. CLAMP SW2 DOUBLE PUSH S W ITCH MTG. CLAMP SW3 DOUBLE PUSH S W ITCH MTG. CLAMP SWITCHES SW1 GREY CO[...]

2. PS-PREG-1791-0503 PCB ASS LY Reference Part Reference Part Designator Description Designation Description TRANSISTORS Q1 BC 109 Q4 BC 557 Q2 MPSA12 Q5 BC 547 Q3 BC 557 ZENERS Z1 4.7 V , ½W Z2 10 V , ½W PRESET VR1 5K ( 3206F ) HOR TRANSFORMER T1 EE25 PULSE TX. 3. Z-DPM/01 REV - 01 X 2 Reference Part Reference Part Designator Description Designa[...]

4. PS-AUX-DC-L1791-0503 PCB ASS LY Reference Part Reference Part Designator Description Designation Description CAPACITORS C1 470µF/35 V , ELE C8 100n F , 50 V , DISC C2 47µF/35 V , ELE C9 470µ F , 35 V , ELE C3 10µF/35 V , ELE C10 470µ F , 35 V , ELE C4 10µF/35 V , ELE C11 220µ F , 35 V , ELE C5 100nF/50 V , DISC C12 100n F , 50 V , DISC C6[...]

6. FRONT PA NEL ASS LY Reference Part Reference Part Designator Description Designation Description POT VR1 5K, WW POT VR3 500E, WW POT VR2 1K, WW POT VR4 50E, WW POT SWITCH SW1 16A/250V ON/OFF S W ITCH 7. MAIN CHASSIS ASS LY Reference Part Designator Description RESISTOR R1 4.7K/2W, MOR R2 0.025E / 25 W SHUNT DIODES CR1 U30D40C (30AMP/400V DUAL DI[...]

1. Power ON / OFF Switch. 6. Current Fine Control. 11. Output ON / OFF Switch. 2. Voltage Coarse Control. 7. CV Mode INdication. 12. Output Terminals. 3. Voltage Fine Control. 8. Current DPM. 13. Remote Sense Switch. 4. Voltage DPM. 9. CC Mode Indication. 14. Remote Sense Terminal. 5. Current Coarse Control. 10. Output Preset Switch. 15. Earth Term[...]

1. INPUT FUSE HOLDER 3. INT / EXT PROGRAM TERMINAL 5. COOLING FAN. 2. MAINS CORD. 4. PROTECTIVE GROUND 6. VENTIL ATION. BACK PA NEL L AYOUT 32[...]

TOP VIEW 33[...]

BOTTOM VIEW OF MODEL : 1790 / 1791 34[...]

FRONT PA NEL CONTROL PCB OF 1790 / 1791 35[...]

POWER MODULE PCB OF 1790 / 1791 36[...]

PRE REGUL ATOR / AUX. P/S PCBs 1790 / 1791 37[...]

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 t[...]

SN: 480-808-9-001 Printed in India (M-00198) B & K PRECISION COR P. 22820 Savi Ranch Parkway Yorba Linda, C A 92887 www.bkprecision.com B PRECISION K [...]