The working principle of switching power supply is essentially to change the output voltage or current by changing the on-time of the adjustment tube in the circuit, and has achieved the purpose of maintaining the output voltage or current stability.
DC-DC switching power supply is composed of diode, transistor, capacitor, etc. The DC-DC switch converts the DC voltage or current into the high-frequency square wave voltage or current, and then smoothed into the DC voltage output by rectification. The DC-DC converter consists of semiconductor switches, rectifier diodes, smoothing and filtering reactors and capacitors. When the input and output need to be electrically isolated, a transformer can be used to transmit the high-frequency square wave voltage to the output side through the transformer.