What Are Relay Switches Used For

Relays are used where it is necessary to control a circuit by an independent low power signal.

What are relay switches used for.

When power flows through the first circuit 1 it activates the electromagnet brown generating a magnetic field blue that attracts a contact red and activates the second circuit 2. In fact some of the first computers ever built used relays to implement boolean gates. A relay is an electromechanical device that uses an electromagnet to open or close a switch. In those cases a relay can be used.

Relays are found hidden in all sorts of devices. The terminal widths used on 4 and 5 pin relays are almost always 6 3mm wide however some more specialist relays can have terminal widths of 2 8mm 4 8mm and 9 5mm. They are used for controlling multiple circuits. The circuit that powers the electromagnet s coil is completely separate from the circuit that is switched on or off by the relay s switch so it s possible to use a relay whose coil requires just a few volts to turn a line voltage circuit on or off.

To turn on an electric motor we need 230v ac supply but in few cases applications there may be a situation to switch on the motor with a dc supply voltage. A 3 way light switch is often found in your house where two light switches can be used to activate a single light. Relays are used for isolating a low voltage circuit from high voltage circuit. A relay is a simple electromechanical switch made up of an electromagnet and a set of contacts.

Here are two simple animations illustrating how relays use one circuit to switch on a second circuit. With solid state relays ssr there are no contacts and switching is totally electronic. Automatic stabilizers are one of its applications where a relay is used. In electromechanical relays emr contacts are opened or closed by a magnetic force.

A relay is an electrically operated switch it consists of a set of input terminals for a single or multiple control signals and a set of operating contact terminals the switch may have any number of contacts in multiple contact forms such as make contacts break contacts or combinations thereof. Overload relays are used for protection of motor from overload electrical failure. This sample is exactly the same as a 3 way light switch the only difference being each physical switch is replaced by a relay. Relays are either electromechanical relays or solid state relays.

If you need to replace a relay make sure you use one with the same terminal layout as it is easy to overlook if you re not aware of the difference. They are also used as automatic change over. The decision to use electromechanical or solid state relays depends on an application s electrical requirements cost constraints and life expectancy. Used to control the electric motor switches.

In this article we will look at how relays work and a few of their applications. This sample demonstrates how a 3 way light switch can be used to activate a light.