On 6/24/2012 1:46 PM, Winston wrote:


I think it would be nifty to come up with a power adapter
for the sound card input to log power as compensated for
power factor. Left channel, volts. Right channel amps.

--Winston

Should be very simple.
Download a dual-channel scope program for the sound card.
Plug an AC wall-wart into one channel, the current probe into the other.
Calibrate out the inherent phase shifts.
for each sample, multiply volts x amps and integrate over a cycle.
It's all ac coupled, so you'd have to figure out what to do with
asymmetrical loads, like any load with a half-wave rectifier.

Most of the design work is in keeping line glitches from
smoking your sound card...or worse.

Wouldn't be surprised if it existed already, but a quick google
search was not fruitful.