DC stabilized power supplies are also called DC voltage stabilizer whose supply voltage mostly is AC voltage. When the voltage or output load resistor of AC supply voltage change, the direct output voltage of the voltage stabilizer can still keep stable. According to the working modes, DC power supplies can be divided into the following categories.

1.Controllable rectification DC stabilized power supply. It adjusts the output voltage by changing the thyristor’s conduction time.

2.Chopping DC stabilized power supply. Its input voltage is unstable DC voltage. It firstly gets one-way pulsating DC by changing the switch on and off of the circuit and then gets the stable DC voltage through smoothing.

3.Convertor DC stabilized power supply. Unstable DC voltage firstly changes into high-frequency AC, then turns into a new DC output voltage through voltage transformation, rectification and smoothing, which is taken as samples to feed back and control inverter’s working frequency, and finally achieves stable DC voltage output.

At present, DC stabilized power supplies are going towards small, efficient and digital development. More and more DC power supplies adopt singlechips to control switching on and off so as to greatly improve the power supplies’ conversion efficiency and equipment’ stability.