AVR based Dimmer

[DynamoBen]

I stumbled across a post on Make.com about an AVR dimmer.

Here is the link:
http://domotica.homeip.net/dimmer.html#dimmer

[ErnieHorning]

This is certainly another way to do it. The isolation for the computer is provided by the two opto’s though the ground on the board is at line voltage. Phil and I talked about this method awhile back and decided that this was too dangerous to provide the details on a board that was frequented by newbie’s. You exchange a lower cost for a potential safety hazard. A micro can drive the gate of a TRIAC directly, but like the text notes, if a TRIAC shorts, it blows up the micro and probably takes out the rest of the board too.

Notice also that the opto’s limit the maximum baud rate to 9600.

[P. Short]

The maximum baud rate through the opto could be increased to 19200 if a 100K resistor is added between the base and emitter of the opto-isolator.

--

Phil

[Wombat]

It would be good when running it off 24V though as we do in Australia then there would not be any high voltages present on the board either.

Wombat