研究了超声波探伤发射电路中各个电阻对超声发射的影响。首先, 对超声波A型脉冲反射式发射电路进行了软件仿真, 针对仿真结果中激励电压峰值偏小的问题, 运用基尔霍夫电压定律详细推导了各个电阻与激励电压的数学关系, 从理论上解释了导致仿真结果偏小的原因。在仿真试验和理论推导计算的基础上, 进一步详细分析了各个电阻与激励和发射脉冲之间的关系。最后得出了开关器件电阻不宜忽略, 充电电阻和阻尼电阻应合理取值的两个结论。

Role of each resistance in ultrasonic inspection transmitting circuit was analyzed in detailedly. A-type-pulse-reflection ultrasonic transmitting circuit was simulated with circuit emulation software firstly. Aiming at solving the peak voltage of activation pulse being a little less than intending peak voltage, algebraic relation between resistance and instantaneous voltage of activation pulse was made correctly based on Kirchhoffs Voltage Law, giving an explanation of the result of emulation above. Furthermore, interrelations between Resistances of transmitting circuit and activation pulse and transmitting pulse are respectively analyzed in detail through the use of emulation experimentation and in theory. Two conclusions about resistance were made at last. One conclusion was that the resistance of switch should not be ignored and the other was that charging resistor and damping resistance should be admeasured suitably.