Product introduction: This motherboard can output 220V AC voltage by connecting a dual 12V transformer. Adapt to the power transformer within 300W W. The frequency of the digital oscilloscope has been adjusted before the module is delivered, so it is generally not necessary to adjust the potentiometer. The potentiometer on the board is used for fine-tuning the frequency. The output is 50Hz square wave. Input voltage: 12V. It has the function of reverse connection protection, and it has no output after reverse connection. It has smaller standby current than ordinary relay board., Weight: 0.26675933702 pounds, Manufacturer: Hfgdnchva