I have a 16 channel light controller that is made strictly for incadescent lighting. It will be controlled via computer program. The outputs are 120 VAC. I would like to hook up 120 VAC relays to some of the channels instead of lights. My question: Will the triacs trigger a relay without any problems? Will I have voltage spike when the relay coil is de-energized and if so what do I need to prevent this?
My guess is that you should have no problems hooking up 120V AC relay coils. If the output triac's were sized to drive normal light bulbs (Wattage up to 100W??) it should be safe to hook up a relay, that I'm sure will not consume more than 2Watt.
You need only to protect DC applications from induced voltages. I can't recall ever seeing any protection (i.e. a diode over a relay coil) for AC applications. (I might be wrong)