Reasonable design of photoelectric switching power supply

Photoelectric switches have their own characteristics. In order to achieve the best cost performance in circuit design, they can be used flexibly. It can be used to select flyback in low-power applications. Larger ones can use a single forward circuit, medium power can use double-switch forward converters and half-bridge circuits, push-pull circuits at low voltages, and half-bridge operation. For high-power output, a bridge circuit is generally used, but a low-voltage push-pull circuit can also be used.

Due to its simple structure, the photoelectric switch saves the flyback power supply and the inductance of the transformer, and is widely used in small and medium power supplies. In the introduction of part of the flyback power supply, only a few tens of watts, more than 100 watts of output power, without any advantages, it is difficult to achieve.

The energy storage of the flyback switching power supply transformer makes the iron core transformer fully utilized. Generally, it is necessary to open the air gap in the magnetic circuit. The purpose is to change the slope of the hysteresis curve. The transformer can withstand larger pulse currents without saturation. In the non-linear state, the air gap in the magnetic circuit is much larger than the completely closed magnetic circuit.