12V Light Control Switch Detection Sensor Photoresistor Relay Module With Extension Cord Item Type: Light Control Switch Module Current: Greater than 100mA Module Instructions: 1. The photoresistor module is most sensitive to ambient light and is generally used to detect the brightness of ambient light. 2. When the ambient light is darker than the set threshold, the relay is closed, and the common end is connected to the normally open end. When the ambient light is brighter than the set threshold, the relay is disconnected, and the common end is connected to the normally closed end. 3. The common end, normally open, normally closed three ports is equivalent to a dual control switch, when the relay coil is powered, the common end is open to the normally open end, when there is no electricity, the common end and the normally closed end are turned on.