The Twin module measures the amount of light that falls on it. In "a" mode, it transmits more power to the next module as the environment gets darker. In "b" mode, it transmits more power to the next module as the amount of light falling on it increases. You can adjust the module's detection sensitivity by turning the potentiometer in the "-,+" directions. Have you ever noticed how streetlights automatically turn on in the evening? Similarly, did you know that solar panels work in the same way?
Twin Module Code: MG16