On Tuesday, 26 September 2017 03:21:57 UTC+1, whit3rd wrote:
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).

zener v/i curves vary, some are terrible near zero i, some straighter.


NT