SSR-Solid state relay,in details

A SSR or solid state relay is used in place of Electromagnetic relay (EMR).

Solid State relay to drive motor

Solid State relay circuit diagram

Here SSR input out terminals are analogous to EMR coil and contact.

Input to SSR is 5,24 VDc or 120 VAc.

Input and output terminals are electrically isolatedcalled galvanic isolation thus saving the delicate motor control circuit from spike,fault current from power circuit.