Design and Characterization of High Efficiency Single-stage Electromagnetic Coil Guns

TL;DR

This paper introduces innovative modifications to single-stage electromagnetic coil guns, including a bipolar pulse, multilayer coil, and permanent magnet projectile, resulting in notable efficiency and velocity improvements demonstrated through experimental testing.

Contribution

The study presents novel coil gun design enhancements—bipolar pulse, multilayer coil, and permanent magnet projectile—that significantly improve efficiency and performance.

Findings

Enhanced magnetic force with bipolar current pulse

Higher projectile velocities using permanent magnet projectiles

Improved efficiency through multilayer coil design

Abstract

This study presents several novel approaches to improve the efficiency of a single-stage coil gun. Conventional designs typically feature a uniformly wound solenoid and a ferrite projectile. For our research, we constructed a microcontroller-based prototype to test several new enhancements, including the use of a bipolar current pulse, a stepped multilayer coil with non-uniform winding densities, and the replacement of conventional ferrite projectiles with a neodymium permanent magnet. These modifications were designed to reduce energy loss and improve projectile acceleration by changing magnetic field strength and effectively controlling the magnetic flux. The experimental results show that the proposed methods resulted in significant efficiency improvements, with the varying current pulse and stepped coil design providing enhanced magnetic force at key points in the projectile's path, and the permanent magnet projectile contributing to higher velocities and efficiencies by leveraging the current pulses. Our findings suggest that combining these enhancements significantly improves coil gun performance, achieving higher velocities and efficiencies. These findings can be applied to future coil gun developments, such as multi-stage coil gun systems.