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B&K Precision 1794 - Manual User Manual

Page 16

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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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