Alarm Clock Light

[bred]

I have an idea to make an alarm that turns my room light on and off in the mornings to wake me up smoother. I was thinking that I take the positive end from the beeper on one of my alarm clocks, and wiring it the base end of a transistor, with the collector/emitter bridging my light switch. Do transistors have a max voltage rating? Can i use any npn transistor? (i think i would need npn) thanks

 

[Brevor]

No dont do that, your transistor will be vaporized as soon as you apply power. Most transistors can't handle line voltages. you need a triac circuit that uses an optoisolator.
A triac can handle AC line voltages and the optoisolator will isolate the line voltage from your alarm clock.

 

[bred]

thanks ill look into that, good thing i asked

 

[bred]

yeah and where would i get one

 

[Dr_Doggy]

doggy_ likes using relays controlled by transistors and watching AC power ratings

 

[Birdman Adam]

I would use the transistor to switch a relay on and off, which will switch your lights.