There are many classifications of switching power supplies. According to the connection method between the switch tube and the load, it is divided into series type and parallel type; according to the excitation mode of the switching device: self-excited type and other excitation type; according to the control method of voltage regulation: Pulse Width Modulation (PWM), Pulse Frequency Modulation (PFM), and Hybrid Modulation (ie, Pulse Width-Frequency Modulation). According to the connection and working mode of the switch tube, the DC regulated power supply is divided into: single-ended DC regulated power supply, push-pull type, half-bridge type and full-bridge type; according to the type of switch tube: transistor, VMOS tube and thyristor.
