It is a regulator circuit with LM317 voltage reducer integrated on the LM317 DC-DC Voltage Reducer Regulator Module. The output voltage is adjusted with the dimmer on it. It gives an output voltage below the input voltage. Specifications: Input: 4.2 - 40VDC

Output Voltage: 1.2-37V

Output Current: 1.5 A

Maximum input-output voltage difference: 40 V

Built-in thermal overload protection

Internal short-circuit current limitation