Development of bipolar nano/microsecond pulse generator

Abstract

To reduce the muscle contraction in the treatment process effectively, a bipolar pulse generator needs to be made. A high voltage bipolar nano/microsecond pulse generator combining with Marx and full bridge circuits is proposed in this paper. We choose the solid-state switching devices instead of spark gap switches. The Marx circuits are the core structure to realize energy compression, and the output of nano/microsecond pulse wave can be realized by MOSFET switching. Finally, the bipolar compound pulse can be realized by full bridge circuit structure. In this paper, the structure of main circuit, working process, control strategy of the bipolar nano/microsecond pulse circuit are analyzed. Based on solid-state MOSFET, main circuit of pulse generator is developed. Signal transmission and isolation between high voltage and low voltage are realized through optical fiber and isolated power supply module. Compared with the traditional high-voltage pulse source, our design has more concise circuit structure and better load adaptability. It can achieve the advantages of fast falling edge, higher pulse frequency, pulse width and adjustable voltage amplitude. The generator can operate with load in a larger range with the use of tail-cut switch. In addition, the discharge circuit is added, and the residual charge on the capacitor can be released effectively after the machine has finished working, which can prolong the life length of the instrument. The experimental results show that the system can generate high voltage pulse source amplitude range of 0~6 kV, frequency 0 ~ 1 kHz , pulse width 200 ns ~ 1 μs square wave pulse, low voltage can generate the amplitude range of 0~2 kV, frequency 0 ~ 1 kHz , pulse width 1 μs~ 100 μs square wave pulse.