B&K Precision 1794 - Manual User Manual
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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 CONDITION
PIN7
--
0V AT CC POT MIN. POSITION.
PIN7
--
0.5V AT CC POT MAX. POSITION.
PIN8
--
+1V TO 3.5V IN CV MODE.
PIN8
--
+10V TO +11V IN CC MODE.
PIN9
--
0V.
PIN10
--
-6mV.
PIN14
--
+10 TO 11V IN CV MODE.
5.4.4
A.
CHECK VOLTAGES AT D3
CATHODE +2V (CV) +10V (CC)
B.
CHECK VOLTAGES AT D4
CATHODE +10V (CV) + 2V (CC)
C. CHECK VOLTAGES AT Z101
CATHODE -4.7V
D. CHECK VOLTAGES AT Z102
CATHODE +10V
5.4.5
CHECK ALL REGULATORS OUTPUT WITH RESPECT TO OUTPUT
+VE COMMON.
REF. PCB NO.
PART NO.
PIN NO. VOLTAGES
U1
IC7812
3
+12V
U2
IC79L05
3
-5.0V
U3
IC7805
3
+5.0V
CHECK WITH RESPECT TO OUTPUT -VE AS COMMON.
U4
IC7812
3
+12.0V
All the above readings are approximate values. The given voltages & waveforms
are refering to a normal working unit. If find any Voltage or Waveform absent at
given points, then trace back to the associated circuits. This complets basic trouble
shooting test points.
5.5
PARTS ORDERING & REPLACING :
5.5.1 OBTAINING REPLACEMENT PARTS : Most electrical parts can be obtained
through your local distributor or representative. However you should be able to
obtain many of the standard components from a local commercial source in
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