12v switching power supply is to use electronic switching devices (such as transistors, field effect transistors, thyristors, etc.) to make the electronic switching devices “on” and “off” continuously through the control circuit, so that the electronic switching devices Pulse modulation is performed on the input voltage to realize DC/AC, DC/DC voltage conversion, as well as adjustable output voltage and automatic voltage regulation.
12v switching power supply 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 supply, or DC/DC voltage conversion; the latter two working modes are mostly used for switching regulated power supply. In addition, the output voltage of the switching power supply 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 supply, or DC/DC voltage conversion; the latter two working modes are mostly used for switching regulated power supply.
According to the way the switching devices are connected in the circuit, the widely used switching power supply can be roughly divided into three categories: series switching power supply, parallel switching power supply, and transformer switching power supply. Among them, transformer 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 be further divided into: forward excitation type , flyback, single-excitation and dual-excitation, etc.; if it is divided into use, it can be divided into more types.
Below we will briefly introduce the working principles of the three most basic switching power supplies, such as series, parallel, and transformer. Other types of switching power supplies will also be analyzed in detail step by step.
Post time: Mar-19-2022