Arduino Clap-On Lights - Introduction to Relays

Everyone knows about clap-on lights, or “clappers”. I’ve always wanted one and my personal philosophy is that the best way to get what you want is to make it yourself. Making clap-on lights is easy with Arduino. What’s more, it gives you the chance to make a simple project with a relay. Knowing how to incorporate relays into your projects opens up a whole new world of what you can do with your Arduino. Without going into too much detail, relays are electromechanical devices that allow you to use a relatively low amount of power (like the 5V from an Arduino pin) to control the switch of relatively high currents or voltages (lamps, motors, heaters, AC circuits, etc.). There are a number of different types of relays, but at their heart they all perform this function. The relay I used for this project is from Ebay(check here), I didn’t know much about it besides it said that it could be used with Arduino (5V control) and it could handle up to 250VAC. Shop around, I got mine for under a dollar. My favorite thing about this project was how easy it was to use the relay.”