1) Zero crossing AC solid state relay, also known as zero triggering AC solid state relay, zero opening AC solid state relay, zero switching AC solid state relay, zero voltage AC solid state relay or synchronous AC solid state relay. For zero crossing SSR relays, the switch state of their output circuit is synchronized with the output signal, that is, when the "synchronous" input signal is turned on, if the load power supply voltage is in the non zero crossing area, the output terminal of the zero crossing solid-state relay will not open; However, if the load power supply voltage reaches the zero zone, the output terminal of the zero crossing SSR relay will be opened, and the load circuit will be opened. This triggering mode can effectively reduce the surge current generated during the SSR opening period and reduce the interference signal that will be transmitted to both the power grid and the input control circuit. Therefore, zero crossing solid-state relays are the most common type in many fields.

2) Random on type AC solid state relay, also known as random switching AC solid state relay, random switching AC solid state relay, random conduction AC solid state relay, random fire AC solid state relay, instantaneous opening solid state relay, non-zero switching AC solid state relay, instant AC solid state relay, instantaneous AC solid state relay, asynchronous AC solid state relay or phase modulated AC solid state relay. The output circuit switching mode of the random SSR relay is only controlled by the control signal and is independent of the power signal, that is, "asynchronous". Power supply. As long as there is an input signal in the input terminal and it is independent of the state of the load voltage, the random solid-state relay will immediately turn on. Due to whether random solid-state relays are turned on or off at any phase of the AC power supply, significant interference signals may be generated at the moment of connection.

3) Peak connected AC solid state relay is also known as peak switching AC solid state relay or peak ignition AC solid state relay. When an input control signal is applied, the peak type SSR relay is turned on at the first voltage peak point of the AC output voltage to reduce surge current. If the input control signal is cancelled, the peak solid-state relay will be turned off。