Electrical crowbar system with novel triggered spark gap devices

Claim 1

An electrical system including a high voltage power supply having a ground terminal and respective positive and negative high voltage terminals, a load having terminals connected to respective terminals of said power supply, and an electronic crowbar having terminals connected to respective terminals of said power supply and including a trigger responsive to fault conditions of said load, the improvement comprising: a master spark gap device and a slave spark gap device in said crowbar, with each of said devices including a tubular insulator having a longitudinal axis; first and second metal end caps on each insulator, with each of said first end caps having an axial perforation therethrough; each device further including a cylindrical electrode and a tubular electrode, with each of said electrodes being within and coaxial with a respective insulator, said tubular electrodes being mounted on said first end caps, said cylindrical electrodes being mounted on said second end caps; each of said devices further including first and second trigger electrodes, one each mounted within and coaxial with a respective tubular electrode; wherein said first trigger electrode is in said master spark gap device with one end coplanar with the end of said tubular electrode not attached to said respective first end cap, said second trigger electrode is in said slave gap device and extends through said tubular electrode and adjacent to the end of said cylindrical electrode not attached to said second respective end cap; and resistance means connected between said second trigger electrode and said first end cap of said master gap device; wherein said first trigger electrode is connected to said trigger, said second end cap of said master gap and said first end cap of said slave gap are connected to said negative terminal, and said second end cap of said slave gap device is connected to said positive terminal.