The Raspberry Pi Relay Board gives your Pi the ability to control high voltage/high current devices, easily makes normal home appliances become intelligent devices.
Features
High quality relays, loads up to 250VAC/5A, 30VDC/5A
Photo coupling isolation, prevent interference from high voltage circuit
Onboard LEDs for indicating relays status
Relay control jumper, allows to control the relays by custom pins other than the default pins
Comes with development resources, including examples in wiringPi, WebioPi, shell, python, and bcm2835
The Relay is a digital normally open switch that controls a relay capable of switching much higher voltages and currents than your normal Arduino boards. When set to HIGH, the LED will light up and the relay will close allowing current to flow. The peak v