Introduction to Relay Module:

The relay module is the function of the switch. The module supplies power, and the corresponding high/low level control signal is input. The relay pulls in, and the COM terminal and the ON terminal are turned on to control the on-off of other circuits. It is not the output voltage. The function of the switch is generally used for weak current to control strong current.

Module size:

1 channel: 50*26*16.5MM

Module interface:

1. DC+: connect to the positive pole of the power supply (the voltage is as required by the relay)

2. DC-: connect to the negative pole of the power supply

3. IN: high or low level control relay pull-in

Relay output:

1. NO: The relay is normally open, the relay is suspended before it is closed, and it is short-circuited with COM after it is closed.

2. COM: relay common interface

3. NC: The relay is normally closed interface, the relay is short-circuited with COM before it is pulled in, and it is left in the air after it is pulled in.

High and low level trigger selection terminal:

1. When the jumper is short-circuited with LOW, it is a low-level trigger;

2. When the jumper is short-circuited with high, it is triggered by high level.

Difference between with optocoupler and without optocoupler:

For the protection of the circuit, the safety with optocoupler is higher than that without optocoupler.