Coil gun : capacitance Vs. Cost question

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Thread Starter


Joined Jul 25, 2008
Hi.. I'm trying to design and build a coil gun. Basically, it's a device to accelerate a ferromagnetic projectile using a magnetic field. To produce the magnetic field, I've decided to use capacitors discharging through a solenoid.
I want to store as much energy as possible in these capacitors. Since large (i.e high capacitance) capacitors are expensive, I'm going with moderately sized capacitors at high voltage (400V).

This is where the question arises:
I could either use one large cap and charge it to 400V or I could use 2 or 3 smaller capacitors in parallel to provide the same capacitance. In terms of cost, it is much cheaper to buy several smaller capacitors (and wire them together in parallel) than to buy a larger capacitor of equivalent capacitance. However, I need to know if there will be any difference in performance between a single capacitor system and a multiple capacitor system..
(For clarification, the circuit just involves a solenoid connected in series with the capacitor(s) )


Joined Sep 20, 2005
Actually, more smaller in parallel are better because it lowers ESR.
Just by the way, coilgun topics are restricted here.


Joined Jul 17, 2007
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