A simple electrical circuit construction.......i need some help as to how to go about this?

Question

hello everybody,

let us assume we connect a light bulb to the power outlet on the wall. we plug it in switch it on it glows. i need something in between the plug and the bulb such that if i provide a 1.5 volt power supply to it, it turns on the bulb and keeps glowing thereafter, if not keeps the bulb is off even though there is power coming from the wall outlet. iam goin to get the 1.5 volt supply from an alarm clock such that i can turn on power supply as and when i want by setting the time even when iam not home........ i ve searched for ready made such supplies but had little luck.

thanks

Answer 1

Sounds interesting - use the 1.5 volts to activate a 120 V relay - a single pole, normally open (SP/NO) relay with a 1.5 volt primary should do the trick. Be sure to switch the HOT (black) lead and not the neutral - it will work either way, but the lamp will be live 120 volts to ground if you switch the neutral.

Be careful, a good 120 volt jolt will wreck your whole day.

Answer 2

That brings back some memories.  The alarm clock that turned on my lamp.

Don't use a reed relay, unless you want it to be auto latching.

At least the reed relay required I get out of bed to turn off the light.

Answer 3

A 1.5 volt relay will do the job. But those are not a common size. More common are 3v, 6v, 9v, and 12 volt relays.

I don't know how you are getting the 1.5 volts from the alarm clock, but perhaps you can get it up to 6v or 9v, which will make finding a relay easier.

.