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Use of transformers/ignition coils in a coil gun. Answered

I've seen a couple of suggestions that an ignition coil, or a decent sizes transformer set up in a similar way, can be discharged into the coil of a coil gun, it the place of the usual capacitor bank.

The main advantages seem to be a much faster recharge time, no need to create 200+V, and the availability of parts.

I only have 540uF worth of capacitors at 200V, which should work for a small gun, but I have several large transformers, and a crate full of ignition coils.

Does anyone know of any reasons why this would not work, or any modifications needed to make this setup work?

Thanks in advance for any replies.


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9 years ago

This doesn't seem right. An ignition coil just outputs a very brief high voltage output (up to about 30kV), I don't think it can drive any type of coil gun.

Your 540uF worth of caps charged to 200V would store about 11 Joules.

An ignition coil stores energy in the inductance of the primary as current flows through it, and then realeases that energy when the primary current is interrupted by the points or the electronic ignition module.

The inductance of the primary of an ignition coil is typically around a few millihenries or so. If it was say 5 millihenries, and you put 6 amps through it, it would store only 90 millijoules. Passing more current through the primary would heat it up and burn in out eventually.

The whole point of the capacitor bank is to store a significant amount of energy that can be quickly delivered to the coil of the gun. I don't think an ignition coil will be of much use.

The Skinnerz
The Skinnerz

Reply 9 years ago

I was wondering why no-one else had done it, so that makes sense. Hopefully I'll get a chance to build it at some point this week, so I'll find out how it goes.

Thanks for clearing that up.