Solid State Relay VS Electric Relay - A Comparison

A relay can be explained as a power switching solution that can be used to smoothen power management without manually opening and closing the switch. To switch the power on and off, a relay simply requires the need for a small electrical signal. This signal can be coined as a “gatekeeper” on a metaphorical level, in the case of a larger electrical signal. It’s ability to have low-power control over a high-power signal is what has made relays so popular throughout the history of electronics. 

There are several types of relays, including a regular electric relay and a solid state relays. The difference between the two can be shown below - 


An electric relay functions with the aid of a physical moving part which connects contacts and the output element of the relay. The movement of this contact is driven using electromagnetic forces from the low-power input signal, facilitating the completion of the circuit that has the high-power signal. The physical component part of the electromechanical relay in most cases makes a “click” sound, which can actually be advantageous in some situations, though it can also lead to a situation of internal arcing which takes a relatively large amount of time to move. 

SSRs employ a low power electrical signal to curate an optical semiconductor signal, most commonly with an optocoupler, that transmits and stimulates the output signal. When started, the input optical signal performs the role of a “switch” that allows a high voltage signal to pass through the SSR’s output element. There are several ways of doing this, but the common element between them all is the lack of moving parts, which is what makes it a solid-state.

Electrical Noise 

Electric relays produce noteworthy signal noise as a result of the mechanical system. While on the other hand, a solid-state relay causes close to negligible electrical disturbance.

Shock & Vibration 

An electric relay system can be impacted by external forces that can result in unreliable and dynamic operation. Conversely, solid-state relays are quite resistant to shock and vibration, which means they are not immune to uncertain performance in hostile environments.

Switching Capabilities

Electric relays typically respond to control signals in 5 to 15 milliseconds. Solid-state relays acknowledge signals 100 times faster - in less than 100 nanoseconds.

Positional Sensitivity 

When talking about electric relays, external forces must be perpendicular to relay action. On the other hand, solid-state relays are positional insensitive. This means that they are perfect for a wide array of mounting positions - vertical or horizontal positions, ‘dead bug’ position or even adjacent mounting.

#SchneiderElectric is a well-established manufacturer of all the different types of relays and their components, along with other appliances/devices/machineries in the fields of electrical management, contactors, and contactor relays #LifeIsOn

Views: 50


You need to be a member of Vanguard Online Community to add comments!

Join Vanguard Online Community

Forum Categories

© 2021   Created by Vanguard Media Ltd.   Powered by

Badges  |  Report an Issue  |  Terms of Service