Hi there,

My problem is I need to make a circuit that senses the AC RMS voltage and takes certain decisions. Now Interfacing to the power line my way are:

1. Use a 20:1 transformer , make a potential divider, on the dc side to account for the diode loss, and do the adc. Tried - results non-linear ,unsatisfactory for the input range.

2. Use an IL300 or similar circuit to make a linear optoisolator - Increases overall price.

3. I am wondering can I use a PIC12F675 to sense the input AC and PWM an I/O to an opto-coupler or shift- out the values

Can you shed some light on the third option.

By the way my circuit would be used on a three phase line-to-line sensing scheme.

Regards

Sougata