Re: Quest for the simplest zero voltage switching

On Aug 12, 6:11 am, JoeyB <joseph.bur...@xxxxxx> wrote:


I'd like to do proportional control on a 120VAC, 1.5kw heating element

So, why not buy a commercial oven controller module? This is a
common
enough task. Usually there's a thermometer involved, too, so the
end result is a thermostat, but you can fake the thermometer easily.

Basic block diagram is: ramp/triangle wave generator with 10 second
period, potentiometer from ramp-minimum to ramp-maximum voltage,
and a comparator with inputs: potentiometer wiper vs. ramp generator-
gives
a duty cycle controlled by the pot setting. The comparator output
goes
to a solid-state relay which powers the heat element.

The CA3059 includes op amps that can perform these functions,
but the 'simplicity' is joined with other characteristics (no second-
source,
high power consumption) that you may not like.

.