How Do Relays Work?

There are several types of relays: furnace relays, circuit board relays, time delay relay (sequencer). In most relays, a lower voltage activates a magnet which closes or opens a switch to a higher voltage circuit. For example, if you connect a low voltage to a 24V furnace relay and test it using a voltage meter, you will notice the meter making a beeping sound, which signifies a complete (closed) circuit. If you power up your coil with the meter still connected to your relay, you will notice the beeping sound stops, signifying an open circuit.

Other Popular Articles

Leave a Comment