Electronic candle LM324
Blowing out a candle is easy - but have you ever tried blowing out an electric light? You can with this project!
This little bit of electronic trickery keeps your friends guessing how you do it.
Turn power ON and carefully adjust the control volume to the point where the LED is about to turn on. Since this trick works best in a dark room, darken the room and tell your friends you must "light" the electronic candle with - what else? - a flashlight.
Shine the flashlight on the CdS cell; the LED turns on. Now you're ready to "blow" your electronic candle out. Cup your hand around the LED and blow on it. Slightly move your hand so that you cover up the CdS cell. Presto! The LED goes out!
To "re-light" it, simply shine the flashlight on it again. Like all good magicians, you'll have to rehearse this trick a few times before performing it for others. It's important that you only try this trick in a dark room. And you'll find that adjusting the control volume to the point to let you do this trick takes some practice.
Have fun with this project - and please don't give away the secret of how you do it!