15 Dec
2020
15 Dec
'20
1:49 p.m.
On 2020-Dec-15, at 11:15 AM, Jules Richardson via cctalk wrote:
On 12/14/20 10:06 PM, Brent Hilpert via cctalk wrote:
Thanks! I guess I can try it first on -5V too and see if the encoder outputs do anything,
and if not give -12V a go. If it works, I like the charge pump idea - I'd probably
ultimately give it its own case and use it externally, so saving a wire is handy.
Just double-checked by measurement, yes, it is -12V.
(It's
definitely -12V, not -5V? I'm just thinking that the -12V noted
on your schematic is quite close the the 15V rating on the cap -
although that could explain why my later setup got caps rated to 35V,
too)
I don't remember whether I traced it or measured it, but I'm fairy
confident, Vgg = -12 is pretty common for GI MOS ICs. I'll try to
remember to double-check it when I have the unit opened again.