Forward-type converter

A type of non-resonant converter. The switching element configuration is multi-transistor, the oscillation method is externally excited, and the control method is PWM. It is an isolated converter with a transformer between the primary and secondary sides. It is mainly used as an AC-DC converter. The structure isolates the primary and secondary sides of a step-down converter using a transformer. Its basic operation is the same as a step-down converter, functioning as a constant voltage power supply circuit that maintains a stable output voltage by adjusting the pulse width according to input voltage fluctuations. On the secondary side, the average output voltage is rectified using a choke coil. This structure is also similar to a flyback converter with an added choke coil. Though it requires more windings, it is highly efficient and has relatively good high-frequency switching performance. Since it includes a transformer, the output voltage can be boosted above the input voltage by adjusting the turns ratio. When the switch is turned off, a high kickback voltage is applied to the switch, so it is necessary to limit this voltage below the rated threshold using components like a snubber. It is widely used in general circuits of electrical and electronic equipment with higher power than flyback converters, ranging from low to high-capacity power supplies.