High-voltage and high-current automatic crowbar

Abstract

In one common type of single-shot high-current crowbar, a short-circuit path is created by the deliberate failure of the solid insulation separating two conductors, by either the explosive fusing of a conductor carrying the circuit current or the controlled firing of a detonator circuit. Unfortunately, in neither technique does the voltage between the conductors directly initiate the explosion, nor is the crowbar necessarily closed within a set range of the circuit voltage. This paper describes a novel switch that overcomes this difficulty. Semiconductor devices are connected such that they explode and break through the insulation shortly after the voltage between the conductors moves outside a set range.

High-voltage and high-current crowbar system based on pseudospark switches: from system design to verification

“…In addition, the added capacitors will result in system redundancy and bulk. A so-called "crowbar" technique [8][9][10][11][12] for preventing the oscillation of circuit and energy re-storage in the capacitors was proposed, that is, the energy storage capacitors are short-circuited at about current maximum. Crowbar system mainly consists of low inductance capacitors, main and crowbar switches for the capacitors, and an inductive load [3,13].…”

Interfacing transformer for a pulsed load current exceeding 1 MA

“…In a series of recent experiments the discharge current was needed to peak at between 1 and 2 MA after about 25 µs, and although sufficient energy for this was available from the bank the rated voltage was much greater than was acceptable by the load. Additionally, to obtain the resonant frequency that gave the required rise time of the load current necessitated the inclusion of a series inductance, limiting the peak current and therefore the supply capability, and reducing the circuit damping to such an extent that a crowbar was needed to protect the bank against excessive voltage reversal [1].…”