Page 2 - Limited Two Year Warranty
Limited Two Year Warranty B & K Precision Corp. warrants to the original purchaser that its product andthe component parts therof, will be free from defects in workmanship andmaterials for a period of two years from the data of purchase. B & K Precision Corp. will, without charge, repair or ...
Page 3 - TABLE OF CONTENTS; SECTION
TABLE OF CONTENTS SECTION PARTICULARS PAGE NO. 1 GENERAL INFORMATION 1 2 SPECIFICATIONS 2 3 INSTALLATION 3 4 OPERATING INSTRUCTIONS 5 5 SERVICE INSTRUCTIONS 10 6 PART LIST 16 7 SCHEMATICS 21 8 CIRCUIT DIAGRAMS 28
Page 4 - GENERAL INFORMATION
1 SECTION - 1 GENERAL INFORMATION 1.1 DESCRIPTION : The 1794 High Current Regulated D.C. Power Supply is completely solid and suitablefor bench operation or standard 19" rack operation. It is a well regulated constantvoltage / constant current supply which delivers 0-32V at 0-20Amps and can bead...
Page 5 - SPECIFICATIONS; Automatic overload and short circuit protection.
SECTION - 2 SPECIFICATIONS OUTPUT VOLTAGE : 0-32V DC continuously variable with coarseand fine voltage controls. LOAD CURRENT : 0-30 Amp max., continuously variable withcoarse and fine controls. CONSTANT VOLTAGE MODEREGULATIONLINE : Less than ± 0.01% ± 2mV for ±10% change inline voltage. LOAD : Less...
Page 6 - INSTALLATION; INITIAL INSPECTION :
SECTION - 3 INSTALLATION 3.1 INITIAL INSPECTION : As soon as the power supply 1794 unit is unpacked, inspect for any damage thatmay have occurred during transit. Save all packing material until inspection iscompleted. If any damage is found, notify the carriers immediately. Our authorisedrepresentat...
Page 7 - INPUT TAP SELECTION FOR 230V OPERATION :; TAP SELECTOR BOARD; REPACKAGING FOR SHIPMENT :
3.8 INPUT TAP SELECTION FOR 230V OPERATION : In case of 230V Mains operation please ensure that shorting links on the Tap Selectorboard is changed to 230V, marked on the PCB for both Mains Transformer &Auxilary Transformer. as per the following diagram. TAP SELECTOR BOARD Please make sure the in...
Page 8 - OPERATING INSTRUCTIONS; TURN ON SETTING PROCEDURE :
SECTION - 4 OPERATING INSTRUCTIONS 4.1 TURN ON SETTING PROCEDURE : The following procedure describes the use of controls and indicators forConstant Voltage and Constant Current Mode of Operation. CONSTANT VOLTAGE (CV) MODE : a. Set ‘POWER ON’ Switch & keep the OUTPUT ON/OFF switch to OFF positio...
Page 12 - SERVICING SAFETY SUMMARY
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 10A Slow blow. Refer fuse replacement to qualified service personnel. DO NOT OPERATE IN EXPLOSIV...
Page 13 - Incorrect control settings can seem like a trouble that
SECTION - 5 SERVICE INSTRUCTION 5.1 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 ormalfunctioning, the unit may become defective. In case, the user wants to carryoutServici...
Page 15 - WARNING
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 ampereor so ) load, check for Bridge Rectifier short or shorted Diode, or SecondaryWinding short, etc 5.3.7 If output voltage or curren...
Page 16 - VOLTAGES & CHECK CONDITIONS; CHECK VOLTAGES AT D3; PIN NO. VOLTAGES; CHECK WITH RESPECT TO OUTPUT -VE AS COMMON.
5.4.3 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 & 3-- +4.9V AT V POT MAX. POSITION. PIN4 -- +12V ALL CONDI...
Page 18 - CAUTION
CAUTION Static discharge can damage any semiconductor component in this instrument. This instrument contains electrical components that are susceptible to damagefrom static discharge. Static voltages of 1KV to 30KV are common in unprotectedenvironments.Observe the following precautions to avoid dama...
Page 19 - FAULT FINDING PROCEDURE; Check Line Voltage for 230V AC or 115V AC, whichever applicable.
FAULT FINDING PROCEDURE ( A ) FUSE BLOWS FUSE BLOW S 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 Dio...
Page 22 - If DPM shows Dot Indication, check DPM IC7107. It might be Damaged.
( 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 & DPM's OK ? ...
Page 26 - POOR LINE REGULATION.; Leaky Summing Capacitor C4 on PREG PCB.
( H ) NO CURRENT CONTROL. NO CURRENT CONTROL Is Current Pot Open ? Replace it. Are W ires 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. Y N Y ( I ) POOR LINE REGULATION. POOR LINE REG...
Page 27 - Check Capcitor C4 and C2 on PREG PCB. It might be Leaky.
( 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. Is Capacitor C4 and C2 Leaky ? Repl...
Page 28 - Check whether 5K Pot is connected between INT and COM Terminal.
( 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. 1. Check whether 5K Pot is connected between INT ...
Page 29 - PART LIST & SCHEMATICS
SECTION - 6 PART LIST & SCHEMATICS 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 6...
Page 35 - BACK
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
Page 36 - TOP VIEW
Page 41 - Service Information; Please return the product in the original packaging with
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 youare using with the device. Non-Warranty Service : Please ...
Page 42 - B PRECISION
SN: 480-808-9-001 Printed in India(M-00198) B & K PRECISION CORP. 22820 Savi Ranch ParkwayYorba Linda, CA 92887www.bkprecision.com B PRECISION K
