AC Phase Control with UNO using the pwm output capability

Projects General Guidance
1

I want to buy a completed phase controller that I might control with an UNO for several voltage varying requirements. I have been unable to find a hobbyist version that is available for purchase. A pcb would be just fine. The only one I've found is on a group that makes pcbs but it is listed as untested. Please help if you know of some option that I might have available to me. My loads would be 120 volt at 1500 watts or less. I would appreciate any help.
Thanks in advance.
Bob

2

1/ What do you want to drive? a motor? heater? lamps? -this determines the size of the components you need. You say 1500w at 120v, which implies a curent of ~13A, but some loads need a lot more than this to start them.

2/ There isn't a trivial way to do this. A triac with a trigger at a certain point in the ac phase is the standard way, but you need to determine the zero-crossing point of the ac source and trigger the triac after a delay. The above principle generates a 'chopped' sinewave - if you need a perfectly smooth sinewave of varying amplitude, this is much more difficult.

in any case the PWM is of no use to you.

regards

Allan.

a thought - I wonder if you could use a LDR with a controllable light source in the standard triac/variable resistor /capacitor/diac circuit? has anyone tried it?

3

You are limiting your options by specifying that you want to control it with the UNO's pwm output.

There is this on Tindie
https://www.tindie.com/products/thewp122/ac-60hz50hz-dimmerssr-controller-board/

and this on ebay
http://www.ebay.com/itm/PWM-AC-Light-Dimmer-Module-50Hz-60Hz-Arduino-Raspberry-LED-Smart-Home-/111983429552

If you want to take a zero cross signal and use the wave chopping phase control method, there is this as well

With all these devices, you are going to have trouble getting 1500 watt output.

4

A LDR can be used, provided that it stands the peak voltage and has sufficiently wide resistance range between "on" and "off".

5

Thanks for all of these suggestions. I will study them. I found this on youtube today that seems to have promise.

6

I ordered this one from the company associated with the circuit. It was $25+ with postage. It does not use PWM but it does what I want. Thanks much.