Design of a high voltage pulse circuit for exciting ultrasonic transducers

Ultrasonic nondestructive testing with characters of fine resolution and low cost has well been developed and widely applied in modern industrial world. The generation of high voltage pulse to excite the transducer has been a critical challenge in an ultrasonic testing system. In this paper a DC/DC converting circuit with an input of 12V and an output of 300V and -300V independently is introduced, so is a pulse generator with pulse width configured by a FPGA with parameters transmitted through a PCI bus by VC++ program. With different connection of the circuit, a positive unipolar pulse, a negative unipolar pulse, a monocycle bipolar pulse and a 2-cycle bipolar pulse can be generated respectively. Finally some pulse characters which may influence the excitation of the ultrasonic transducer are analyzed, the spectrum signature of each type is presented in the later part of this paper.