Self-excited series power adapter

　　Switching power supply products are widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instrumentation, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, liquid crystal displays, LEDs Lamps, audio-visual products, security, computer cases, digital products and instruments and other fields.

Among them, VT is the switch tube of the power adapter, which is controlled by the excitation pulse and works in the cut-off and saturation state. C1 is the filter capacitor in the mains voltage rectification filter circuit. VD is a freewheeling diode, and its function is to provide a power supply path for the load when the switch is turned off. L is the energy storage inductance (ie switching transformer). C2 is the filter capacitor at the output end of the power adapter.

In the past, power adapters generally used linear power supplies, which required a very bulky transformer to provide sufficient inductive reactance, so the power adapter was very bulky. Today's power adapters and chargers generally use modern electronic technology. The switching power supply technology directly rectifies the 220V AC power to obtain a signal similar to a square wave. Without the bulky transformer, the volume can naturally be made smaller.

Many people are confused about what is a charger and what is a power adapter, especially after the power adapters are made smaller and smaller, they not only look alike, but also have similar parameters, which makes us foolishly divided. Not sure.