What Are Relay Switches Used For

They are also used as automatic change over.

What are relay switches used for. In fact some of the first computers ever built used relays to implement boolean gates. In electromechanical relays emr contacts are opened or closed by a magnetic force. In this article we will look at how relays work and a few of their applications. This sample is exactly the same as a 3 way light switch the only difference being each physical switch is replaced by a relay.

The decision to use electromechanical or solid state relays depends on an application s electrical requirements cost constraints and life expectancy. 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 relay is an electromechanical device that uses an electromagnet to open or close a switch. 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 either electromechanical relays or solid state relays. Relays are normally used in the control panels manufacturing and building automation to control the power along with switching the smaller current values in a control circuit. Relays are found hidden in all sorts of devices. 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.

A relay is a simple electromechanical switch made up of an electromagnet and a set of contacts. 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. Used to control the electric motor switches. Relays are used for isolating a low voltage circuit from high voltage circuit.

This sample demonstrates how a 3 way light switch can be used to activate a light. In those cases a relay can be used. Relays are used where it is necessary to control a circuit by an independent low power signal. Microprocessors use relays to control a heavy electrical load.

They are used for controlling multiple circuits. However the supply of amplifying effect can help control the large amperes and voltages because if low voltage is applied to the relay coil a large voltage can be switched by the contacts. 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. 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.

Overload relays are used for protection of motor from overload electrical failure. 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.