Dimmer Question

[greeneggs83]

Hello, I need to build a dimmer for a 120v lamp. I cannot buy a dimmer because the area that I have is too small. I found a schematic that will work but I am too unfamiliar with TRIACs to know exactly what to buy. The schematic that I am interested in can be found here:

http://www.aaroncake.net/circuits/dimmer.htm

It says that I need a "40502 TRIAC" I'm not exactly sure what type of TRIAC that is. If this is a product number, please give me specs or guidance on what kind of Triac I should buy. Please help! Thanks.

-Sam Allen

 

[OperaHouse]

I'd say go buy a dimmer for $2.99, take it apart and repackage it. Doubt you can find all these parts for even twice that price. Most later circuits use a diac in place of the neon lamp or have this built into the triac. This triac would be any generic triac rated at 400V and 4A. A Radio shack bubble pack triac with this voltage would likely work. The gate of this triac may need to be a little more sensitive than most because of the neon trigger.