EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Oxmstr on July 30, 2020, 12:38:55 pm
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I want to make a analog clock that some people already made, but I want to make it bigger (larger needle) and with back-light (as in car tacho / speed meter). I'm looking at 91C16 or C4 moving coil analog meters because they are cheap and I want to mod them so a mistake won't be expensive.
Has anybody modified a analog panel meter? I tried looking on the interwebs, but there aren't many resources about these meters, seems like people that use them already know everything about them. Locally I can only get 10 V full range and I would need to make them 3 V, but that shouldn't be that hard.
Also how to know when to use a shunt for ammeters? I didn't see any markings on the front plate that stated what kind of shunt to use. There are 50 mA full scale meters do these require shunts?
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Get yourself a book on electrical measurements. Most of your questions will be answered there.
Working on these is a job for a watchmaker. Adding to the problems is the strong magnet in most meters.
A shunt needs to be used when measuring currents higher than the basic movement. The trap is to make it precise enough and to use special alloy that has low temperature coefficient.