Sometimes you want to control AC devices such as lamps, fans, or other home appliances with Arduino. However, since the Arduino operates at 5V, it cannot directly control these high voltage devices.This is where the relay unit comes in. You can use the relay unit to control the alternating current and the Arduino to control the relay. This project walks you through how to set up a single channel relay unit to power a lamp or other device.

The kit contains the following components