提出了基于STM32和FPGA的超声波探伤系统,设计了激励脉冲宽度、幅值和重复频率可调的发射电路。该电路使用高压电源模块,可以提供0~400 V可调的直流电压,重点运用基尔霍夫电压定律推导了电容充放电时间,分析了电容电阻对发射电路的影响,确定了阻容参数的选择。根据计数器方法,用FPGA编程实现了触发脉冲对开关元件的控制,满足了触发脉冲重复频率可调的要求。最后对发射电路进行了验证,结果表明电路性能良好、具有很好的实用性。
In this paper, an ultrasonic inspection system based on STM32 and FPGA was proposed and transmitting circuit with tunable pulse width, amplitude and repeated frequency of the stimulant were adjustable in transmitting circuit. The circuit u- ses a high-voltage power supply module providing 0~ 400 V adjustable DC voltage. Based on Kirchhoff's Voltage Law, charging and discharging time was deduced, the influence of capacitors and resistors on the transmitting circuit was analyzed and the choice of resistance and capacitance parameters was confirmed. By adopting the design approach of counter , the trigger pulse, which can control the switching and meet the need of variable repeated frequency ,was designed by using FPGA, which increases the flexibility of the system. Finally, the transmitting circuit was tested ,whose result shows that this circuit has good performance and high utility.