反激式恒流一次侧控制模式的研究

Research of Flyback Converter Constant Current Primary Control Mode

反激式变换器输出恒流特性在许多场合,如恒压恒流充电器、LED恒流驱动器等有着重要的应用。输出恒流采用二次侧电流反馈的方法会增加电路的成本和复杂性。通过采用一次侧调节的方法来控制输出恒流,在变压器的一次侧检测输出电流的信息,避免了二次侧电流采样电路和光电耦合器等元器件,减小了电路的复杂性,提高了电路的效率。通过实验得到采用一次侧调节的实验波形和数据,验证了一次侧调节的先进性。

The flyback converter output constant current characteristic has important applications in many occasions, such as constant pressure constant current charger, the LED constant current drive, etc. The method of secondary side current feedback can increase the cost and complexity of the circuit. The primary side adjustment method is studied to control the output constant current in this paper. Output current information is obtained from the primary side of transformer, avoiding the secondary side current sampling circuit and photoelectric coupler components, reducing the complexity of the circuit, improving the efficiency of the circuit. The experiment is done to acquire the experimental waveforms and data with the primary side regulation, and results verify the advanced nature of the primary side regulation.