Switching power supply uses electronic switching equipment (such as transistors, field effect tubes, thyristors, etc.). By controlling the circuit, the electronic switching equipment is continuously turned on and off, allowing the electronic switching equipment to pulse the input voltage. Modulation, and then realize DC/AC, DC/DC voltage conversion, and the output voltage can be harmonized and automatically stabilized.
There are three working modes of switching power supply: fixed frequency and pulse width mode, fixed frequency and variable pulse width mode, and variable frequency and pulse width mode. The former working mode is mostly used for DC/AC inverter power supply, or DC/DC voltage conversion; the latter two working modes are mostly used for switching regulated power supply. In addition, the switching power supply output voltage also has three working methods: direct output voltage method, average output voltage method, and amplitude output voltage method. Similarly, the former working method is mostly used for DC/AC inverter power supply, or DC/DC voltage conversion; the latter two working methods are mostly used for switching regulated power supply.
According to the connection method of switching equipment in the circuit, switching power supplies can be roughly divided into three categories: series switching power supply, parallel switching power supply, and transformer switching power supply. Among them, transformer-type switching power supply (hereinafter referred to as transformer switching power supply) 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 also be divided into: forward type. , flyback, single-excited and double-excited, etc.; if divided according to their uses, they can be divided into more varieties.
Post time: Apr-15-2024