Is there a device to measure electrical usage over a span of about a day,
and plot a graph of power use versus time? If it can transfer logged data to
a computer that would be even better.

I want to measure the power consumption of appliances like refrigerator,
dehumidifiers, air con, and get an idea of their duty cycle. These
appliances cycle between high and low power, so something like a
"kill-a-watt", which I already have, can't give me an overall picture of
power consumption.

"david" wrote in message
...
Is there a device to measure electrical usage over a span of about a day,
and plot a graph of power use versus time? If it can transfer logged data
to a computer that would be even better.

I want to measure the power consumption of appliances like refrigerator,
dehumidifiers, air con, and get an idea of their duty cycle. These
appliances cycle between high and low power, so something like a
"kill-a-watt", which I already have, can't give me an overall picture of
power consumption.


Inneresting project, worthwhile.
There was a news report within the past week or so, how these appliance
ratings are way way off.
I think Consumer Report was thumping its chest about this, getting some rare
and much needed PR for itself.

What this newsbyte ditty did *not* address was the issue of, well, if the
absolute measurements were off, were at least the *relative* measurements,
or the *rankings* accurate.
One would hope that at least THAT much was valid in these energy ratings....
but who knows.....

I found power meter software while googling "diy bicycle generator",
without the quotes.
I think this link had something:
http://wattsview.com/DIY-BYO-Power-w...r-software.htm

If not, other results from that search had pc-based stuff. Really
interestig stuff.

You may also want to try googling "pc-based oscilloscopes" or "pc-based
voltmeters" or something similar, which might provide generic pc-based
volt-amp meters, that you could structure for your own purposes.

--

EA