What does a varistor do when added in parallel with the load of a Solid State Relay?

A varistor, when added in parallel with the load of a Solid State Relay, serves primarily to protect the circuit from voltage spikes or surges. It does this by clamping excess voltage and allowing it to safely dissipate, thus reducing the impact of transient voltages that could damage sensitive components.

This protective mechanism is particularly critical in applications where electrical noise and voltage spikes are prevalent, as it helps maintain the integrity and reliability of the entire circuit. By absorbing these surges and preventing them from affecting the load, the varistor effectively minimizes potential disruptions and extends the lifespan of the connected components.