This paper provides design and development details of the generation of bipolar High Voltage (HV) square wave pulses for the excitation of low frequency ultrasonic transducers. Such a circuit is required for the purpose of ultrasonic inspection of components, particularly where high energy is required to insonify the attenuative medium, such as concrete. A HV (±350 V) square wave pulse has been generated by an ultrafast complementary Metal Oxide Semiconductor Field-Effect Transistor (MOSFET) pair, which is driven by high speed MOSFET drivers. The generated bipolar square wave pulse has been utilized to energize a 108 kHz ultrasonic transducer to operate in the pulse-echo mode for the evaluation of a concrete test block. The receiver amplifier filters the received low-amplitude echo signals, which are reflected back from a discontinuity, and amplifies further for signal to noise ratio enhancement. The pulser board designed has been tested and evaluated for its functionality to measure ultrasonic velocity in the highly attenuative concrete medium up to a depth of 1 m. The measured value of acoustic velocity was compared with the value obtained from the commercially available ultrasonic pulse velocity instrument, and the values obtained are within ±5%.

中文翻译：

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用于混凝土结构无损检测的超声波双极方波脉冲发生器的设计与开发

本文提供了用于激发低频超声换能器的双极高压 (HV) 方波脉冲生成的设计和开发细节。这种电路需要用于部件的超声波检测，特别是在需要高能量以对衰减介质（例如混凝土）进行声波处理的情况下。HV (±350 V) 方波脉冲由超快互补金属氧化物半导体场效应晶体管 (MOSFET) 对生成，由高速 MOSFET 驱动器驱动。产生的双极方波脉冲已被用于激励 108 kHz 超声波换能器，使其在脉冲回波模式下运行，以评估混凝土试块。接收放大器过滤接收到的低振幅回波信号，这些回波信号从不连续点反射回来，并进一步放大以增强信噪比。设计的脉冲发生器板已经过测试和评估，其功能是测量高度衰减混凝土介质中的超声波速度，深度可达 1 m。将声速测量值与市售超声脉冲速度仪测得的值进行比较，测得的值在±5%以内。