The output of the 3636R relay is generally a strong current controlled by weak current. This is a statement in circuit control.In many automation equipment, the 3636R circuit ultimately needs to control some execution components (such as motors, electromagnets). The control of these execution components can be achieved through switching devices such as relays, bidirectional thyristors, transistors, etc. Therefore, for the output end of the circuit, there are corresponding types such as "relay output, bidirectional thyristor output, transistor output". The 3636R is actually very simple. An ordinary relay is equivalent to a single pole double throw switch, which controls the external circuit with three pins. When the current is not controlled (the default state), the middle pin is connected to the left pin, and when the control current is applied, the middle pin is connected to the right pin. The relay needs the current to act on the electromagnet, but due to the large current, relying solely on the microcontroller I/O port is not enough to make the relay close, A driver should be added (to amplify the power and provide sufficient current to the relay), and the microcontroller should use the I/O port to control the driver. Then, the driver circuit (such as UM2003) should output enough current to make the relay close, and that's all.