Where can i buy a TRIAC, like at radioshack, sparkfun or a store like this?
i've come across a radioshack that sold triacs once. i was suprised, but most of their components are pretty cheap (read: crappy). i would order one from a place like digikey or mouser, unless you have some other electronic stores locally.
I just noticed last night that sparkfun started carying a TRIAC aslo, but digikey and mouser would have a much better selection.
Or if you have an unused lighting dimmer laying around, you can salvage it out of that.
The older dimmers will be resistive, which won't help you, but the new ones they sell at Home Depot all have triacs, and also the shielding hardware so that you won't be broadcasting in the AM range, if you care.