The product is mainly composed of column contact regulator, sampling, protection, and control circuit, low-speed synchronous motor mechanism, and compensation transformer. When the mains voltage is unstable or the fluctuation caused by the user's load change occurs, the sampling circuit will process the voltage signal and send it to the synchronous motor to drive the carbon brush of the cylindrical contact voltage regulator to move up and down, ensuring the stability of the output voltage. It has large capacity, low loss, high efficiency The advantages of wide voltage stabilization range, high accuracy, strong protection function, and reliable operation.