PIC to Relay

[RussMartin]

Sometimes too cheap is just that, and we have to remind ourselves of John Ruskin's poem...

In the words of an on-the-air fumble by John Cameron Swayze in the early days of live television advertisements: "Remember, with Timex, you get what you pay for; and you don't pay very much."

[The Master]

Ok, heres that schematic. Im sorry its not the best looking one ever. I did it in M$ paint :P

The lefthand side of the optoisolator works exactly the same as an LED. Check the datasheet for the specific one your using for the voltage. Usually i put a 1K resistor between it and the PIC. I always put a 1K resistor between the opto and the G pin of the triac too although i cant remember why (maybe someone else can clarify this bit).

It may or may not help you but ive included a circuit that i designed to control 4 lights using triacs. I usually find that a PCB layout helps me more than a schematic so you have both just incase. The triac im using is a "BTA08-600B 8A 600V" and the opto is a "MOC3020M". Both resistors either side of the optos are 1Ks. I have a few of these circuits connected up and working perfectly

[aratti]

I think useful to add the attached schematic for all who want to use TRIAC for their ac application.
Remember that the triac side is always connected to the main. Be very careful !!

Al.

[Kalind]

OK cool!! Im taking a look at the triac now. For the solid-state, isn't there a "flyback" diode required?

[RussMartin]

I think useful to add the attached schematic for all who want to use TRIAC for their ac application.

I suggest the upper schematic. You might be happier with a MOC3033 or other MOC303x. You'll also discover that the 180 ohm resistor is not necessary.