RogerN wrote:



Anyone here mess with signal conditioning for current transformers? Seems
that I need a "precision rectifier" circuit and a capacitor to charge up
to the peak, then scale to RMS amps.
No, you don't need such complexity. Put a small bridge rectifier directly
on the transformer winding, then a burden resistor sized to give you a
few Volts at the desired current. Add a capacitor and you have a
voltage approximately proportional to current. Then, rig a simple
comparator to trip at the desired point.

Now, one problem with this scheme is that under some loads
it could start cycling on and off, cutting the heater on and off
every second or so. So, you might need to add some hysteresis to
the comparator.

Jon