Fuse Opening Switches for Pulse Power Applications

The high power fuse represents a practical opening switch concept that is routinely used in circuits where currents can exceed 25 Megamps1 and in which the time scales range from 100–s of microseconds2 down to 10–s of nanoseconds.3 The fuse is an electrical conductor which experiences a very rapid rise in resistance as a result of ohmic heating. The heating is driven by the current which the fuse is intended to interrupt, and this heating leads to melting and eventually to vaporization of the conductor. The fuse is, thus, fundamentally a very reproducible one-shot device, and may, within limits, be thought of as totally passive.