[Boatanchors] Long-term AC voltage monitor

[Mike A]

On Mon, Jan 05, 2015 at 05:23:43PM +0000, Rick Poole WA1RKT wrote:
> Thanks, Rob. Yup, I know. Measuring filament voltage has the same problem as
> measuring AC voltage coming out of the wall... you only get the value that
> is present right then. So I still need some kind of long-term monitor that
> doesn't break the bank (doesn't take much to break the bank, these days).

I'd give serious thought to something like an Arduino, with one or more built
in A-to-D converter(s), fed by a transformer or voltage divider. The ADCs are
fast enough to watch the actual waveform, see peak voltages and glitches, and
log them to a thumbdrive or another computer, and an Arduino is damn cheap.
If you can figure out a way (NTP or equivalent) to do accurate timing, then
you've got a frequency (or period, anyway) monitor in addition to the voltage
monitor.

There is a neat combination of Arduino+Raspberry-PI, all on one card, that
would be absolutely ideal for this, and under $100. 

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin