Starter Relay

A Starter Relay is an electromechanical device that is operated by an electrical current. It is an electrical switch that opens and closes under control of another electrical circuit. It was invented by Joseph Henry in 1835.

Characteristics of Starter Relay

• It can be considered as a form of electrical amplifier because it can control an output circuit of higher power than the input circuit.
• Usually, a starter relay has four terminals. Two of them are of low current and the other two are of high current.
• Relays are switches used in many applications. They are simple to use, have long life and are highly reliable.
• The input of relays can be electrical and output directly mechanical, or it can be the other way round.

Types of Automotive Starter Relays
There are two basic types of Relays

• Electromechanical: They have moving parts, cost is low, no heat sink is required and can switch AC or DC with equal ease.
• Solid State Relay: They have no moving parts

Functions of Automotive Starter Relay

• Relay controls a high-current circuit with a low-current signal in the starter solenoid of an automobile.
• It detect and isolate faults on transmission and distribution lines by opening and closing circuit breakers.
• It isolate the controlling circuit from the controlled circuit when the two are at different potentials, for example, when controlling a mains-powered device from a low-voltage switch.

Maintenance of Automotive Starter Relay

• The operations of the relay should checked carefully at the time of installation and periodically at every 6 months or after 1 year.
• A protection circuit is recommended to prolong the life of expectancy of a relay. It will reduce noise and prevent the carbon generation at the contact surface when the relay is opened.