Get 5V 9V 12V 24V 1 Way Relay DIY Kit Control Board Expansion Board Kit Features: (1) Board size: 51MM * 23MM (2) Supply voltage: 5V, 9V, 12V, 24V(depending on the relay voltage) Interface definition: VCC: positive power of relay module GND: negative power of relay module Signal: Control signal. When the input is high, the relay will be closed and the indicator light will be on. Supports 3.3V single chip or 5V single chip. Use reminder: VCC and GND input the same voltage as the relay. When the signal terminal input is greater than or equal to 3.3V (high level), the relay is pulled in. When 0V is input, the relay is reset. During the test, VCC and the signal terminal can be short-circuited, the relay is closed, and the indicator light is on, indicating that there is no problem. Package included: 1 x 1 Way Relay DIY Kit 5V 9V 12V 24V 1 Way Relay DIY Kit Control Board Expansion Board See detail