I would like to build a temperature sensor that switches on and off a mains supply to keep what I am heating at a set temperature. However, I am wondering where to get power for my micro (a PIC).
I have two main questions:
1) I have seen these fairly cheap: **broken link removed** but can't work them out (I'm assuming that's AC-AC), could this sort of thing work? Or is there a better approach? I'd rather not use batteries or another DC supply if possible, if I already have mains power through the circuit!
2) Would a relay or TRIAC & opto-isolator be best? The book I am reading suggests a TRIAC which doesn't appear to need a separate DC power supply, other posts online seem to suggest that is desirable for a relay. I will be switching a maximum of 60W, the heat mat I have now is 18W.
Thanks.
I have two main questions:
1) I have seen these fairly cheap: **broken link removed** but can't work them out (I'm assuming that's AC-AC), could this sort of thing work? Or is there a better approach? I'd rather not use batteries or another DC supply if possible, if I already have mains power through the circuit!
2) Would a relay or TRIAC & opto-isolator be best? The book I am reading suggests a TRIAC which doesn't appear to need a separate DC power supply, other posts online seem to suggest that is desirable for a relay. I will be switching a maximum of 60W, the heat mat I have now is 18W.
Thanks.