   Theory

Section descriptions:

Coilgun Basics 1, 2, 3 -

Brief introduction to coilguns and instructions on how to build a simple table-top coilgun.

Electromagnetic Basics 1, 2, 3, 4 -

Describes the basics of electromagnetic forces and shows how these operate in general.

Coilgun Fundamentals 1, 2 -

This section looks at the principles involved in the operation of a coilgun.

Coil Resistance -

If you don't have a high resolution ohmmeter then this formula will give you a good approximation to the coil resistance.

Optimised Coil Parameters 1, 2, 3 -

Find out how the circuit resistance and coil parameters affect the current density and field strength in the coil.

Coil Power Handling -

Make sure that you don't melt your coils. Find out how to estimate the temperature rise.

Inductance Measuring -

A transient technique is described which can be used to determine the inductance of a coil.

Inductance Calculation -

FEMM can be used to determine the approximate inductance of a coil operating at low frequencies.

Switching Devices -

This describes the most common semiconductor devices which can be used in a coilgun system.

Triggering Circuits -

The main types of triggering are discussed and some example circuits are given.

Measuring Speed -

How fast does your coilgun fire that projectile? This explains two methods which can be used to tell you just that.

Projectile Design -

If you want your projectiles to go ballistic then think about some of these design issues.

Metallic Tubes -

Metal accelerator tubes mean one thing, eddy currents. This section shows how to reduce eddy current paths in a metallic tube.

Coil Construction Issues -

High power coilguns experience large dynamic forces so the coils need to be constructed with inherent strength. Some simple ways to achieve a strong coil are discussed.

Energy Sources -

Suggestions about what can be used to power a coilgun.

Mathematics -

Covers some of the math used in electromagnetics.

Finite Element Software -

A brief look at two free finite element numerical field solution packages, Quickfield and FEMM.  