At 02:10 PM 18/08/98 EDT, you wrote:
>        I'm playing around with some ideas for RMS to DC conversion and
>thought I'd bounce ideas off the list (and yes, the DC output IS to drive
>a PIC!).
>

OK, so we already have a device to measure the RMS level, just that it is
not isolated. So why not use a simple Voltage to Frequency converter? Or use
one of those isolated opamps from Burr Brown?
Just some ideas if you need something that works. I see many problems with
the incandescent light source, one of them being repeatability over time.
Non linearities can be fixed up by putting the sensor into a bridge
configuration and good old PIC software.

Dennis