BECKMAN CIRCUITMATE AM12

[lionelkjh]

Hi there! I am looking for the diagram of the BECKMAN CIRCUITMATE AM12 multimeter: could someone help me?? Thanks in advance! (view the photo)

[lionelkjh]

sniff

[Gyro]

I can't see whether this is a passive moving coil multimeter or whether it has active electronics to increase the ohms-per-volt input impedance. The image is low resolution so trying to scale up the image doesn't help.

Analogue meters lilke this are usually fairly simple internally (single or double sided PCB, through hole components) and it is relatively easy to reverse engineer the schematic. If you are trying to debug specific problem, eg, current, voltage or resistance functions then tracing those specific areas should reduce the task.


Edit: A quick web search revealed some information, it is an active meter using a pair of descrete jfets in a bridge configuration... https://worldradiohistory.com/hd2/IDX-UK/Technology/Technology-All-Eras/Archive-Practical-Television-IDX/90s/Television-Servicing-UK-1993-03-OCR-Page-0036.pdf

Non of the usual manual sites seem to have anything and I can't find any internal photos.

[Chris56000]

Hi!

This meter is a clone of the Huang Chang HC–5050E & you can get a booklet with a circuit diagram and component list in the back from Elektrotanya here :–

https://elektrotanya.com/altai_hc-5050e_analog_multimeter_sm.pdf/download.html

Chris Williams

[lionelkjh]

THANKS A LOT!!