基于FPGA的光弹调制器用高压驱动电路设计

Design of high voltage driving circuit based on FPGA for photoelastic modulator

为满足光弹调制器对高电压、高稳定和精确易控制的驱动电压需求,设计了一种基于FPGA控制、全桥结构LC谐振升压的高压驱动电路。该电路与传统的光弹调制器驱动控制电路相比,大幅降低了直流电源的电压输入要求,通过DDS调节方波频率来控制光弹调制器工作频率,调节方波占空比来控制输出电压。该电路应用于光弹调制器实验,结果表明在光弹调制器的谐振频率下,外部直流电压为5 V时,方波占空比范围为0~50%,对应电压峰-峰值可调节范围为0~840 V。电路具有稳定可靠、操控方便、带负载能力较强等优点,能够实现光弹调制器驱动电压实时精确的控制。

In order to meet the requirement of high voltage,high stability,accuracy and easy control driving voltage for photoelastic modulator,a high voltage driving circuit based on FPGA control and full bridge LC resonant boost is designed. Compared with the traditional photoelastic modulator driving control circuit,it reduces the DC power supply input voltage,controls the photoelastic modulator frequency through DDS square wave frequency,and adjusts square wave duty cycle to control the value of output voltage. The results of photoelastic modulator experiment show that the square wave duty cycle range of 0 ~ 50% corresponding to peak voltage can be adjusted in the range of 0 ~ 840 V at the resonant frequency of the photoelastic modulator when external DC voltage is 5 V. The circuit has the advantages of reliable,easy control,heavy load capacity,and it can realize the real-time and accurate control of the driving voltage of photoelastic modulator.