8 Channel 5V Relay Module DC 5V Eight Channels Isolated Relay Control Module With Screw Terminal For Arduino DC5V With Optocoupler Protection Electronics Circuitry & Parts

• Power supply and relay instructions, lit, the disconnect is off;
• The input signal, signal, common Terminal and start conducting;
• Useful for appliance control;
• DC or AC signal, control, you can control the 220V AC load.
• One normally closed contact and one normally open contact
• Triode drive, increasing relay coil
• High impedance controller pin
• Pull-down circuit for the avoidance of malfunction
• Power supply indicator and Control indicator lamp
• The module is compliant with international safety standards, control and load areas isolation trenches.

Note: On the high level and low level-triggered mode, friends who do not understand, have a look

• High-level trigger refers to the signal voltage between input and trigger, can be understood as a signal input with VCC cathode short-circuit triggered away;
• Low-level trigger refers to the signal voltage between the input terminal and Earth OV trigger, can be understood as the signal input terminal and the GND negative electrode short circuit triggered away  1-channel relay module connection.