controlling a hotwire

[mackrackit]

needs wire with a PTC

What is PTC?

[mister_e]

Thermistor I guess. ICL

[cncmachineguy]

Hello all, I am back to trying to get this done. Any suggestions on the transformer in the melabs example? I don't need the power supply side, so really I guess I just need the zero crossing sync.

So basiclly, a logic level TRAIC (as linked by Dave) connected to an output and a way to detect the Zero crossing is all I need, Yes?

[kellyseye]

Hello all, I am back to trying to get this done. Any suggestions on the transformer in the melabs example? I don't need the power supply side, so really I guess I just need the zero crossing sync.

So basiclly, a logic level TRAIC (as linked by Dave) connected to an output and a way to detect the Zero crossing is all I need, Yes?

Exactly.

The transformer must be rated for at least the maximum power you would expect to use plus a margin for safety. Since the VA rating defines the power, you could be very adaptable on the choice of transformer in terms of volts and current but, generally speaking, keeping the volts low (<24VAC) and the current high (probably around 3A to 5A) is safer for the user.
There would be a quite large selection available on the likes of eBay if you search.

[cncmachineguy]

half asleep, but here is my beginning. Looking for some help here if anyone wants to help me fix this

[mister_e]

The cool thing of Triac is they often come short when they burn. So ask yourself if it's safe to plug it to the Main first. If the wire break... how dangerous it will be if someone try to change it LIVE.

Kinda stuff like that

[Jerson]

I recommend you look up the MOC3021 opto-triac to interface your triac to the PIC. Your current scheme does not seem workable.

[kellyseye]

What is PTC?

Positive Temperature Co-efficient

when the resistance increases as the temperature does.