一种实验室用开关电源的设计与调试

Design and Debugging of Switching Power Supply for Laboratory

设计了一种基于电子变压器的高效率低成本实验室电源。该电源有四路输出,前三路固定输出,分别为36、15、5 V;另一路输出电源从0~30 V连续可调。电路采用具有双反馈控制环的BUCK型变换器来保证输出电压和电流的连续可调。该变换器的主电路采用L4960作为控制芯片;利用电阻采样法和差动放大器、比较器原理设计了采样电路、反馈控制电路。为了进一步降低负载调整率和输出纹波,设计了恒流放电负载和低压差动态滤波器。实测数据表明,该实验室电源的功率因数达到0.95以上,效率达到80%以上,输出电压纹波仅为10 m V。

A high efficiency and low cost laboratory power supply is designed based on electronic transformer is designed. The power supply can provide four outputs,one is fixed output 36 V,the other fixed output 15 V,the third fixed output voltage 5 V,and the fourth output is adjustable voltage from a 0 ~ 30 V continuous adjustable,. the The circuit uses a BUCK type converter with a dual feedback control loop to ensure continuous adjustable output voltage and current. The main circuit of the converter using uses L4960 peripheral circuit,hence it is simple and the its price is cheap as the control chip. The sampling circuit and feedback control circuit are used resistance sampling method and differential amplifier,a comparator principle design of sampling circuit,a feedback control circuit. In order to further reduce the load adjustment rate and the output ripple,the design of the constant current discharge load and low pressure differential dynamic filter are adopted. Measured data show that the power factor of electronic transformer is more than0. 95,the efficiency reaches more than 80%,output voltage ripple is only 10 m V. It greatly reduces the volume and weight compared with traditional laboratory power supply,and also reduces the cost.