The structure and working principle of solid state relay

First of all, the main function of the solid state relay is to realize contactless connection and disconnection, that is, it does not have an arc when the AC contactor is connected.According to the solid state relay I have used now, the single-phase solid state relay uses DC24v to control the connection and disconnection of the single-phase contact. The working principle is the same as that of the intermediate relay. 24v electricity, the contact is closed. The DC is the control coil and the AC output controls the load.

First of all, I see that the solid state relay in the picture can withstand 10A circuit, AC480VAC, which means that L1----T1 is allowed to pass the maximum voltage of 480V, and the following 3V--32V DC, which means A1----A2. Can be connected to 3V - to 32V DC.

In the picture above, we look at three solid state relay wiring methods, AC 24V---480V, pay attention to the incoming line of L1, T1 appears to the load, A1 below is connected to the positive pole of the DC power supply, and A2 is connected to the negative pole of the DC power supply. The solid state relay in the middle of the above picture is 220V, the live wire goes into A1, and the neutral wire goes into A2. The rightmost picture in the above picture is DC power, which needs attention.

Internal circuit of solid state relay, composed of capacitors and diodes

The solid-state relay controls the light, the live wire enters the solid-state relay, goes out through the solid-state relay and enters the light, and the neutral wire directly lights the light. The solid-state relay is equivalent to a switch and a normally open point.

Below, give a DC power supply to the solid state relay. When the solid state relay is powered, the upper normally open contact is closed. At this time the light came on.

How to better understand the working principle of solid-state relays, first of all, we regard the solid-state relay as a switch. When the power is supplied below, the contacts of the solid-state relay are closed, and the solid-state relay returns to its initial state when the power is turned off below. It is equivalent to a light, when the power is on, the light is on, and when the power is off, the light is off.