When the mains voltage is converted into the designed voltage through the input switch and the transformer is turned on, it enters the pre-stabilizing circuit. The pre-stabilizing circuit is to perform preliminary voltage regulation on the desired output voltage, and its purpose is to reduce the high-power adjustment. The tube voltage drop between the input and output of the tube can reduce the power consumption of the high-power regulating tube and improve the working efficiency of the DC power supply. stabilize the voltage. After the pre-regulated power supply and the filter ①, the voltage obtained is basically stable and the DC current with relatively small ripple will be accurately and quickly tested by the high-power regulating tube controlled by the control circuit, and the voltage regulation accuracy and performance will meet the standard. After the DC voltage is filtered by the filter ②, the output DC power that I need is obtained. In order to obtain the output voltage value or constant current value that I need, we also need to sample and detect the output voltage value and current value. And send it to the control/protection circuit, the control/protection circuit compares and analyzes the detected output voltage value and current value with the value set by the voltage/current setting circuit, and drives the pre-regulator circuit and the high-power adjustment tube. The DC stabilized power supply can output the voltage and current values we set, and at the same time, when the control/protection circuit detects abnormal voltage or current values, the protection circuit will be activated to make the DC power supply enter the protection state.