Investigation on 10/350 Crowbar Pulse Current Circuit

Structure of main air discharging switch and a crowbar TVS (triggered vacuum switch) are designed and their triggering characteristics are investigated. The experimental results showed that for TVS the operating voltage range is from 1.3 kV to 120 kV, its maximum delay time is 400 ns and its jitter is ±10 ns. Based on these results the crowbar 10/350 μs (i.e., with a front time of 10 μs and a duration of 350 μs) pulse current circuit and its controlling circuit are designed. With a 10 μF stored capacitor C and a 6 μF waveform forming induction, a pulse current is generated with a maximum of 100 kA, front time of 10 ns and duration of 350 μs. This pulse waveform can be used for testing SPD (surge protective devices).