Static Relay

Static Relay

The conventional relay type of electromagnet relays can be replaced by static relays which essentially consist of electronic circuitry to develop all those characteristics which are achieved by moving parts in an electro-magnetic relay.

For example, in an induction type relay, the operating time can be adjusted by adjusting the distance travelled by the disc whereas in a static relay it can be achieved by adjusting the value of the resistance in the R-C time delay circuit. In other words static relays are capable of performing the same functions with the use of electronic circuit control as an electro-magnetic relay performs with the use of moving parts or elements.

Static relays are superior to electro-magnetic relays in the following aspects:

1. The moving parts and the contacts are largely eliminated. The only moving element in a static relay is the final tripping contact.
2. C.T.s and P.T.s employed are of lesser VA rating as static relays require a very little volt-ampere for their operation.
3. More precise and high speed operation.