中文摘要：

以峰值电流型PWM控制芯片UC3842为核心设计了一种新型多功能反激式开关稳压电源，该电源具有6路直流隔离电压输出。介绍了其工作原理和外围电路设计。为了满足电磁兼容性和安全性要求，设计了EMI抑制电路。详细介绍了一种新型变压器绕组缓冲电路的设计方法，着重介绍了反激式变换器的变压器设计过程，包括齐纳箝位电压的计算、实际占空比的计算、电感值的计算、磁芯的选择、各路输出绕组匝数的确定以及气隙的计算。实现了对输出电压的负反馈调节及各种保护机制。实验结果表明，该开关稳压电源具有稳压性能优良，纹波小，电压调整率、负载调整率高，体积小，质量轻，电磁兼容性好等优点。

英文摘要：

With the peak current PWM control IC UC3842 as its core,a muhifunctional flyback switching power supply is designed,which has 6 channels of isolated DC voltage output. Its operating principle and peripheral circuit are introduced. The EMI suppression circuit is designed to meet the requirements of electromagnetic compatibility and safety. The design of a new-type snubber circuit for transformer windings is introduced in detail and the design of its transformer is emphasized,including the calculation of Zener clamping voltage,actual duty-cycle ratio and inductance,the selection of magnetic core,and the determination of winding turns and air-gap. The negative feedback regulation of output voltage and various protective mechanisms are realized. Experimental results show that the designed switching power supply has stable voltage output,small tipple,high voltage and load regulation rates ,small size ,light weight and excellent elec- tromagnetic compatibility.