Service Manual M695

Testset

Doc code 638 718

09/93 3077-HWE

 

 

The test box: three multimeters

Digital voltmeters

Supply for digital voltmeter

Circuit diagram on page 18-5

POWER SUPPLY

Diagram on page 18-6

MICROSCOPE

CONTROL

Diagram on page 18-7

One digital voltmeter is assigned to each of the functions POWER SUPPLY, MICROSCOPE CONTROL and XY-GEAR. The signals reach the measuring instrument through a rotary switch.

Range of measurement: 1.999V - with overflow display (OL)

Measurement precision: 1% +- 1 digit, 2 measurements/second

Auxiliary voltage:

7 . . .

15VDC

The power is derived from the 24V supply of the XY-gear (at control unit MEL61/62 only). Three galvanically-separating DC converters each reduce the voltage to approx. 12V each.

Rotary switch S1:Displaces the decimal point on the display by one digit to the right for the 24V - measuring ranges.

Rotary switch S1:

Level 1 ... Selects current- and voltage ranges.

Voltage distributor:

1/10 for 12V range

 

1/100 for 24V ranges

Current measurement range: Voltage drop across 0.1 ohm resistor.

Measuring ground:

P G N D - 2 4 VM I C R O S C O P E

 

SENS - PGND

 

GND-XY - 12V / 24VXY-GEAR

Rotary switch S3:

Selects those signals which are assignable

 

either to microscope A or to microscope B.

Rotary switch S2:

Selects the control signals to and from the

 

microscope.

Voltage distributor:

1/10

Measuring ground:

SENS