Fast, solid-state crowbar switch to protect high power amplifier tubes

Fast crowbar switches are needed to protect high power amplifier tubes from potentially damaging internal arcs. Such a switch needs to have a fast turn-on to a low impedance state while also having the capability to discharge large amounts of stored energy. These switches have historically been thyratron tubes or spark gaps [1]. We will describe a new hybrid solid-state approach that combines a small fast switch with a slower large area slow switch to achieve a low cost crowbar switch for these applications up to 50 kV.