4. Input control signal voltage: (0-1.5V state low level relay ON) (2.5-5V state high level relay OFF)
5. The blue KF301 terminal is more convenient to connect to the control line.
DC+: Connect the positive pole of the power supply (powered by the relay voltage)
DC-: Connected to the negative pole of the power supply
CH: Relay module signal trigger terminal (low level trigger is valid)
High and low meaning:
High-level triggering means that there is a forward voltage between the signal trigger terminal (IN) and the negative pole of the power supply. Usually, a positive trigger is used to connect the positive pole of the power supply to the trigger terminal. When the trigger terminal has a positive voltage or triggers at voltage, the relay pulls in.
Low-level triggering means that the voltage between the signal trigger terminal and the negative pole of the power supply is OV, or the voltage at the trigger terminal is lower than the voltage of the positive pole of the power supply. When the voltage is low enough to trigger, the relay is pulled in, usually A triggering method in which the negative pole of the power supply is connected to the trigger terminal, so that the relay is attracted.