电离层光度计中的高压电源设计

摘要

利用SG1525芯片来实现电离层光度计上的高压稳压电源.高压电源由SG1525芯片搭建的脉宽调制(PWM)电路、功率开关管、高频变压器、RC滤波电路和取样反馈电路组成.重点介绍了所搭建的脉宽调制电路,分析了影响电路最佳工作频率的因素,给出了各部分的设计参数和测试结果,最后总结了利用PWM来实现高压电源的注意事项.经过试验测定,在负载电流小于0.741 mA的条件下,高压电源稳定在-1 700V,满足设计要求,可用于电离层光度计中.%A kind of High Voltage Unit (HVU) was designed by using SG1525,which was used to provide the bias voltage to the photomultiplier in tiny ionospheric photometer.Every parts of the HVU system were described,including the Pulse Width Modulation (PWM) with SG1525,power switches,high-frequency transformer,RC filter circuit,and the sampling and feedback circuit.The PWM circuit set up with SG1525 is also introduced,the factors are analyzed,which influenced the optimum working frequency of the HVU system.The design parameters of each part and the experiment results were presented.Several design principles about the HVU system were discussed at the end.The high voltage remains at the level of-1 700 V when the amplitude of load current is below 0.741 mA,which meets the design requirement and could be used in the tiny ionospheric photometer.