A relay is an electrical device that is used to switch on or off an electrical circuit by opening or closing its contacts in response to a signal. It can be thought of like a toggle switch, where the physical switch can be moved using an electronic signal. This allows relatively low voltage / low current circuits to control much higher power circuits in a relatively isolated manner.

This small relay is a SPDT (Single Pole, Dual Throw) contact arrangement with a coil (toggle voltage) of 5VDC and a current requirement of approximately 160mA. The contacts can handle up to 380VAC / 110VDC with the Normally Open (NO) contact rated to 10A and the Normally Closed (NC) contact rated up to 20A. On application of 5V DC to the coil, the common pin will become disconnected from the NC contact, and connected to the NO contact. The relay is non-latching, and removal of power to the coil will revert to the “normal” state.

Typically these will be used in a special footprint on a circuit board, but they can be made to fit into perfboards with a little creativity or use one of our handy SPDT Relay Breakout PCBs.