Solid state relays have high reliability: there are no mechanical parts inside the SSR, and the structure adopts a potted fully enclosed structure. Therefore, SSR has the characteristics of vibration resistance, moisture resistance, corrosion resistance, long life and reliable operation. Solid state relays have low noise: AC SSRs all use zero-crossing trigger technology, so they can effectively reduce dv/dt and di/dt in the line. Solid state relays have fast switching speeds: SSR switching speeds are much faster than mechanical switches. , the turn-on and turn-off times of DC solid-state relays can reach tens of microseconds. SSR has the advantage of being compatible with logic circuits such as TTL and CMOS.