This is a very interresting circuit and I've been looking for something like that for a while. Got all the components, followed the shcematic and built the breadboard for testing.
Unfortunately, it does not work. I can get the LED to blink at various rate using the variable resistance but the AC circuit refuses to work. I use 5vdc as input to the 555 timer (output is 2.9vdc into the optocoupler). since I am in Canada, it's 120VAC instead of 220 but I dont think it makes a difference. Also, I am using a LED house bulb instead of incandescent. Tried both to no avail. The TRIAC is a bt136 and tested OK.
Thanks for the help and insights