We have already discussed the working of electrical relays. Now we are going through different types of electrical relays.
- Electromechanical Relays
- Solid State Relays
Read more about Different Types of Protective Relays here
General Purpose Relay
General Purpose Relays are cost-effective 5-15 Amp switching devices used in a wide variety of applications. These are found in computers, copy machines, and other consumers electronic equipment and appliances.
Typical Applications: Lighting controls, time delay controls, industrial machine controls, energy management systems, control panels, forklifts, HVAC.
Power relays also contain an armature, a spring and one or several contacts. If the power relay is designed to normally be open, when power is applied, the electromagnet attracts the armature, which is then pulled in the coil’s direction until it reaches a contact, therefore closing the circuit. If the relay is designed to be normally closed, the electromagnetic coil pulls the armature away from the contact, therefore opening the circuit.Power relays are used for many different applications, including:
- Automotive electronics
- Audio amplification
- Telephone systems
- Home appliances
- Vending machines
Power relays are used for switching a wide variety of currents for applications including everything from lighting control to industrial sensors.
These relays are switching devices for control and auxiliary circuits and are used to control, provide signals and interlock switching devices and switchgear panels.
A contactor is a large relay, usually used to switch current to an electric motor or other high-power loads. Large electric motors can be protected from overcurrent damage through the use of overload heaters and overload contacts. If the series-connected heaters get too hot from excessive current, the normally-closed overload contact will open, de-energizing the contactor sending power to the motor.
Solid State Relays
How Solid State Relay Works?
- Advantages of Solid State Relays include low EMI/RFI, long life, no moving parts, no contact bounce, and fast response.
- The drawback to using a solid state relay is that it can only accomplish single pole switching.