Decreasing the range of ammeter?

Thread Starter

onlyvinod56

Joined Oct 14, 2008
363
Hello,

I have an analog ammeter 3A full scale.
I want to convert it to 100mA full scale.
I know how to extend the range but how to decrease it? WP_20160103_003.jpg WP_20160103_002.jpg
 

dannyf

Joined Sep 13, 2015
2,197
That black coil-like wire between the two terminals is of low resistance and extends the (current) range of the meter.

Getting rid of it or replacing it with the right value resistance will get you the desired range.
 

MikeML

Joined Oct 2, 2009
5,444
Get rid of the internal shunt. Determine the sensistivity of the intrinsic meter movement (likely ~50mV or 1mA full-scale). Then calculate new shunt based on the meter sensitivity.
 

wayneh

Joined Sep 9, 2010
16,162
I think I'd use 300mA full scale if you plan to keep the same back plate. You'll remember it now but the next guy won't, and that next guy is probably you in a few years.
 
Top