power factor measurement

Archiver

I am looking for a way to measure power factor on an electrical mains
outlet.

I had a circuit that utilized two comparators and an AND gate to accomplish
this. The concept was that each comparator would output a pulse width equal
to the positive cycle of the voltage and current. The output of each
comparator was fed into the AND gate which *should of* produced a pulse of
varying pulse width equivalent to the phase difference of the voltage and
current. I would then measure the pulse width via the stamp.

But it *ahem* blew up. Lots of smoke and sparks to say the least. My
mistake was not isolating the mains from the circuit. I am not well versed
in optocouplers, so I am asking the gurus .... any suggestions? I bet that
there is probably a better way to measure the power factor.


Thanks,
--Craig

Archiver

Hi Craig, Suggest you check out recent back issues of "Analog Dialog" which
is put out by Analog Devices Inc., a top notch IC manufacturer based in the
Norwood, Mass. area. They have devices which will measure power factor.
Analog Devices has sales through the major distributors and a rep
organization. A top notch company with web site at www.analog.com. Hope
this helps. Burt

Archiver

Thanks. In fact, I have been investigating their series of power
metering IC's. I was just hoping for a simple circuit to measure the
power factor instead of going the IC route.

I'll check out Analog Dialog.

--Craig


--- In basicstamps@y..., burtsz@a... wrote:
> Hi Craig, Suggest you check out recent back issues of "Analog
Dialog" which
> is put out by Analog Devices Inc., a top notch IC manufacturer
based in the
> Norwood, Mass. area. They have devices which will measure power
factor.
> Analog Devices has sales through the major distributors and a rep
> organization. A top notch company with web site at
www.analog.com. Hope
> this helps. Burt