Relay Pin Description June 2, 2019 5V Relay: Pinout, Description, Working & Datasheet. Relays are most commonly used switching device in electronics. Let us learn how to use one in our circuits based on the requirement of our project. components101.com Three Switch Light Switch3 Way Electrical SocketVehicle Wiring SchematicsTwo Way Dimmer SwitchCentral Air Control WiringElectrical Control Circuit DiagramSamsung Dryer DiagramHow To Wire A 240v Plug