Power conditioner for a coil-gun

The authors describe a power-conditioning scheme for introducing currents sequentially into a linear array of coils which form the barrel of a coil gun. The projectile, a conducting cylindrical sleeve, is driven by the force exerted on it by a traveling magnetic-wave packet created by the barrel currents. Since the rate of energy transfer is proportional to the projectile velocity, it was convenient to divide the barrel into three separate sections, corresponding to the low-, medium-, and high-velocity parts of the projectile motion. Each section is excited by a different method, chosen to satisfy the need for the most efficient utilization of the energy stored in the power supply capacitors. Experiments with a breadboard model, which test the feasibility of the medium-velocity power-conditioning scheme are described. In the medium-velocity section, each stage utilizes the preceding capacitor and its left-over energy to increase the voltage and the frequency of the next stage. It was demonstrated that for a six-stage configuration the energy utilization efficiency using the power conditioner is higher than that achievable with an arrangement of six individual precharged source capacitors by a factor of two.