The Arduino platform is a great way to control lights, buzzers, displays and more - but what if you have a device that doesn't run on the Arduino's native 5 volts? One simple way to do it is to use the RobotGeek Relay. This little board will use a signal from a 5v microcontroller to make a mechanical connection. This connection is physically seprated from the arduino, meaning you can connect devices that have different voltages up to it!
The RobotGeek Relay can be run in 2 ways. Connect your external device through the NO(Normally Open) terminal, and the electro-mechanical connection will be made whenever you send a 5v signal to the relay board. Connect your external device through the NC(Normally Closed) and the external device will be normally on, turning off whenever the relay receives a signal.
The standard 30mm X 20mm mounting pattern make these boards easy to mount in any if your projects.
These relays can handle up to 5 amps at 250 volts