[Nut-upsuser] Newbie question: real-time power usage monitoring?

[James Cameron]

On Wed, Oct 19, 2011 at 08:40:40AM -0400, Christian Convey wrote:
> You're right - I *am* looking for total energy expenditure (Joules,
> Watt-hours, etc.)  I have no specific desire to do that integration in
> my own code.

What I used was a kit design from Silicon Chip in 2004, one retailer
provides this as
http://www.altronics.com.au/index.asp?area=item&id=K4600
but there are others.

It is significantly more expensive than the consumer watt hour meters
available today.

It contains a chip that accumulates the counts independently, and
a microcontroller driving the display and panel buttons.

If I was doing what you are doing, I would replace the microcontroller
with one that relays the readings over USB, serial, or ethernet.  Then
I'd worry about high voltage isolation and chuck in an optoisolator.

I imagine there are better designs for the job.  I'm only sharing my
limited knowledge of the subject.  ;-}

Your later point about having the device do the counting and then seeing
timed results reminds me of my very early work on the same subject ... a
rotation sensor that emitted a millisecond counter alongside a rotation
counter, so that it didn't matter when the host computer processed the
data.

http://quozl.linux.org.au/speedo/

-- 
James Cameron
http://quozl.linux.org.au/