Description microscope M695

Service manual M695

09/93 3077-HWE

Doc code 636 718

 

 

24V supply

Lamp Control

 

Zoom Servos A+B

 

Focus Servos A+B and

 

The final stages for lamp, zoom- and focusing motor, is supplied with 24V

 

on these boards, via switching regulators.

PGND, SENS and

Microscope-Ground (PGND) and SENS are linked within the microscope.

Logics-Ground

The high lamp current causes a voltage drop of about 0.6V to PGND. This

 

 

voltage is passed to the control unit through SENS.

Situation up until July

For the reason indicated above, Logics-Ground is about 0.6V below PGND

1993 ...

in the microscope. The voltage drop at PGND affects the level of the control

 

 

signals, and so longer swingarm cables than the standard ones can result in

 

 

malfunctioning.

 

New situation as from

Logics-Ground in the control unit is connected to SENSE and so is partly

August 1993

dependent on PGND. The effect on the control signals is therefore less and

 

 

longer swingarm cables can be used.