Analogue moving coil meter range extension?
On Sunday, September 24, 2017 at 8:43:06 PM UTC-7, T i m wrote:
On Sun, 24 Sep 2017 17:52:51 -0700, mike wrote:
I'm far too lazy to do the math on how nonlinear it will be.
I do like the idea of printing my own scale and if this basic one
works, I might go for a bigger / better meter that I can open etc.
Yep, that's a good idea.
And, there's NO NONLINEARITY unless you apply bias less than the zener
voltage breakdown, because of Norton's theorem: any bunch of
resistors and voltage sources (the zener is a voltage source) is
identically a current source with a shunt resistance. Offset by
a constant, you can get; nonlinearity, you can't. The meter magnetic field
is the only source of nonlinearity (and meter manufacturers do pretty well
on keeping that uniform).
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