One advantage of solid-state relay (SSR) over conventional electro-magnetic relay (EMR) is its tear and wear free operation. S201S01 from Sharp is a good example. Here is the circuit diagram of a DIY ...

Even though the function of single phase and three phase relays are quite similar, their applications can vary significantly. This is primarily due to the characteristics of three phase power circuits ...

The universal timing circuit in Figure 1 converts almost any SSR into a solid-state timer. The only requirement is a dc control-signal input (usually 3 to 32V dc) for the SSR. The minimum signal input ...