A Reexamination of Length Requirements for Electroexplosive Opening Switches

The dependence of electroexplosive-opening-switch resistance on the length of exploding wires has been reexamined. Numerical modeling of exploding wire fuse resistance based upon experimentally fit equations shows that, assuming that restrike is prevented, shorter lengths of the conducting medium result in higher final switch resistance. The complex relationships between the circuit current, switch resistance, and energy dissipated in the switch are detailed to analyze the length dependence of the switch resistance. A discussion on the limits of minimization of the switch length is discussed in terms of switch restrike. Errors in assumptions used to formulate the previous standard method of switch length design are examined, and the principles involved in maximizing the switch resistance are applied to propose a new method for switch length design.