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Ed_Dinning · 11th Mar 2016, 10:16 am

Hi Gents, on the topic of range extension, how about using a bridge circuit with a low current 250v supply and a 20:1 divider with "statistical" resistor chains as set out above for good accuracy.
This divider could be nulled against the 12v5 ref voltage with a centre zero galvo or electronic meter.
With the meter to be checked connected, the 250v supply could be adjusted to give null and the meter reading noted.

It would reduce the accuracy of the system at this voltage but should still form a useful check on the meter's higher voltage ranges.

Thoughts please gents.

Ed

11th Mar 2016, 10:16 am	#16
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Another DIY voltage reference... Hi Gents, on the topic of range extension, how about using a bridge circuit with a low current 250v supply and a 20:1 divider with "statistical" resistor chains as set out above for good accuracy. This divider could be nulled against the 12v5 ref voltage with a centre zero galvo or electronic meter. With the meter to be checked connected, the 250v supply could be adjusted to give null and the meter reading noted. It would reduce the accuracy of the system at this voltage but should still form a useful check on the meter's higher voltage ranges. Thoughts please gents. Ed