Control of discharge time using physical contact in a two-stage coil gun

Abstract

In this study, a coil gun was designed using a trigger that can discharge a capacitor using physical contact. Controlling the discharge time of the capacitor in a multi-stage coil gun is an important factor for the final velocity of the projectile. To control the discharge time, we used the physical contact of the projectile and the trigger and controlled the point in time when discharge occurs by sensing the projectile location using a sensor. Controlling the discharge using sensors allows for more accurate timing control than physical discharge systems, but the circuit is more complex, and the high current results in a higher risk of malfunction and higher costs. In contrast, systems that use physical contact are simple, have low risk of malfunction, and have low cost. The velocity of the projectile was predicted using the electromagnetic analysis simulation program MAXWELL, and the final velocity of the projectile was compared to the results of a prototype.