> I need a simple SCR or TRIAC based heater power control. I have
> heater of 2kW(220V~) and I want to deliver only 0 to 500W to it.
>
> anyone have a idea or link or anything that can help me? I think
> about optocupler with zero cross unit but I need help about that?

A couple of circuits here that should help

http://home.clear.net.nz/pages/joecolquitt/txless.html

For a heater you can count zero crossings and switch the element
on/off for whole cycles (not suitable for lights, too flashy). The closer
to the z-c point you turn the element's power on/off the less chance
of creating EMI. For setting the power output, may I suggest

http://home.clear.net.nz/pages/joecolquitt/0pots.html

or perhaps use an IR system built around ideas on the first page or
DIP switches. The light chaser here

http://home.clear.net.nz/pages/joecolquitt/0chaser.html

uses a rotary panel switch diode-ANDed to make a 4-bit BCD
encoder

Take your pick

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