Turning a smoke machine on/off with a triac

[mister_e]

Most commercial model I know and see on my workbench each months just use a Relay for the Heater but a Triac for the pump (obviously for flow/burst control). If your control is not fancy, you could just use relays, but if you manage the heater temp, the smoke flow/burst, current limit, etc etc... then TRIACs (BTA serie with built-in snubbers) are the obvious choice.

[The Master]

Ok, Thanks. I will go with the triac then. I'm using BTA already so thats good.

I did think about using a relay but I've used those in the past for the pump motor and they cause all nearby PICs to reset (I had a post on here a few years ago about it). The solution was to use triacs. I've used diodes in the past on the low voltage side of relays to stop current flowing backwards. Maybe something like that on the high voltage side would fix the problem but I would rather use a triac instead.

[ardhuru]

A triac would be fine. Even better, add a few lines to detect the zero crossing, and switch on right after that. That should reduce the inrush current.

Regards,

Anand

[The Master]

Good idea. I have at least 1 pin spare on the PIC. I'll do the same for the pump too

[keithdoxey]

A triac would be fine. Even better, add a few lines to detect the zero crossing, and switch on right after that. That should reduce the inrush current.

Regards,

Anand

Or drive the triac with an opto isolator that includes zero crossing detection.