9 types of switching power supply
(1) According to the technology, the connection mode of the switching tube, and the power supply technology, the switching power supply can be divided into series switching power supply and parallel switching power supply. The switching tube of the series type switching power supply is connected in series between the input voltage and the output load, which belongs to the step-down voltage regulator circuit. The switching tube of the shunt type switching power supply is in parallel between the input voltage and the output load, which belongs to the booster voltage regulator circuit.
(2) According to the excitation mode, the switching power supply can be divided into self-excited and other-excited. In the self-excited switching power supply, a positive feedback loop is formed by the switching tube and the transformer technology ‘> high-frequency transformer to complete the self-excited oscillation, similar to the blocking oscillator; The other excited switching power supply must be attached to an oscillator, and the switching pulse generated by the oscillator is added to the switching tube to control the on-off and cut-off of the switching tube, so that the switching circuit works and has a DC voltage output.
(3) According to the modulation mode, the switching power supply can be divided into pulse width modulation (PWM) mode and pulse frequency modulation (PFM) mode. PWM is a way to control the output voltage stability by changing the switching pulse width, while PFM is a way to control the switching pulse period (that is, frequency) after amplifying the error value when the output voltage changes by sampling comparison.
(4) According to the size of the output DC value, the switching power supply can be divided into boost switching power supply and buck switching power supply, and can also be divided into high voltage switching technology ‘> high voltage switching power supply and low voltage switching power supply.
(5) According to the output waveform, the switching power supply can be divided into rectangular wave and sine wave circuits.
(6) According to the output performance, the switching power supply can be divided into constant voltage constant frequency and variable voltage frequency conversion circuit.
(7) According to the number of switching tubes and the connection mode, the switching power supply can be divided into single-ended, push-pull, half-bridge and full-bridge, etc. The single-ended type uses only one switching tube, the push-pull type and the half-bridge type use two switching tubes, and the full-bridge type uses four switching tubes.
(8) The switching power supply can be divided into forward type and flyback type according to the energy transfer mode.
(9) According to the soft switching mode, the switching power supply has current resonance type, voltage resonance type, class E and quasi-class E resonance type and partial resonance type