The quality switching power supplies uses electronic switching devices, and through the control circuit, the electronic switching devices are constantly "on" and "off", allowing the electronic switching devices to pulse-modulate the input voltage, thereby realizing DC/AC, DC/DC voltage conversion , as well as adjustable output voltage and automatic voltage regulation.

Quality switching power supplies generally has three working modes: frequency, pulse width fixed mode, frequency fixed, pulse width variable mode, frequency, pulse width variable mode. The former working mode is mostly used for DC/AC inverter power supplies, or DC/DC voltage conversion; the latter two working modes are mostly used for switching regulated power supplies. In addition, the output voltage of quality switching power supplies also has three working modes: direct output voltage mode, average output voltage mode, and amplitude output voltage mode. Similarly, the former working mode is mostly used for DC/AC inverter power supplies, or DC/DC voltage conversion; the latter two working modes are mostly used for switching regulated power supplies.
According to the way the switching devices are connected in the circuit, the quality switching power supplies can be roughly divided into three categories: series switching power supplies, parallel switching power supplies, and transformer switching power supplies. Among them, the transformer switching power supplies can be further divided into: push-pull type, half-bridge type, full-bridge type, etc.; according to the excitation of the transformer and the phase of the output voltage, it can be further divided into: forward excitation, flyback, single excitation There are many types, such as type and dual-excitation type; if it is divided into use, it can be divided into more types.