Switching power supplies have three conditions
Working Principle of Switching Power Supplies
The working process of switching power supply is quite easy to understand, in linear power supply, let the power transistor work in linear mode, unlike linear power supply, pWM switching power supply is to let the power transistor work in the on-state and off-state, in these two states, the volt-ampere product added to the power transistor is very small (in the on-state, the voltage is low, and the current is large; in the off-state, the voltage is high, and the current is small) / power devices The volt-ampere product on the power device is the loss incurred on the power semiconductor device. Compared to linear power supplies, pWM switching power supplies work more efficiently by "chopping", i.e. chopping the input DC voltage into pulses of amplitude equal to the input voltage amplitude. The duty cycle of the pulse is adjusted by the controller of the switching power supply. Once the input voltage is chopped into an AC square wave, its amplitude can be raised or lowered by a transformer. The number of output voltage groups can be increased by increasing the number of secondary windings in the transformer. Finally these AC waveforms are rectified and filtered to obtain the DC output voltage. The main purpose of the controller is to keep the output voltage stable and the process is very similar to the linear form of controller. This means that the functional blocks of the controller, the voltage reference and the error amplifier, can be designed in the same way as a linear regulator. The difference is that the output of the error amplifier (the error voltage) passes through a voltage/pulse width conversion unit before driving the power tubes. Switching power supplies have two main modes of operation: forward conversion and boost conversion. Although the differences in the arrangement of their components are small, the operating processes vary considerably, and each has its own advantages for a particular application.
Three conditions for switching power supplies
Switching
Power electronics operating in a switching state rather than in a linear state.
High frequency
Power electronics operate at high frequencies rather than low frequencies close to the industrial frequency.
DC
Switching power supplies output DC instead of AC or they can output high frequency AC such as electronic transformers.
