An Analysis of the Initiation Process of Electroexplosive Devices

Abstract

Electroexplosive devices, EEDs or squibs (an electric resistance encapsulated by a primary explosive), fundamentally convert electrical energy into heat, solely to start off an explosive chemical reaction. Obviously, the EED activation shall not happen by accident or, even worse, by intentional exogenous influence. From an ordinary differential equation (ODE), which describes this device thermal behaviour for both continuous and pulsed electrical excitation, a remarkable, but certainly not intuitive, dependence of the temperature response on the heat transfer process time-constant is verified: the EED temperature profile dramatically changes as the time-constant spans a wide range of values, from much lesser than the pulse width to much greater than the pulse period. On the basis of this dependence, important recommendations, concerning the EED safety (and efficient) operation, are presented.