Re: [MV] About active armor

From: J. Forster (jfor@quik.com)
Date: Thu Aug 07 2003 - 18:33:13 PDT


Employee@MilVeh.com wrote:

You might recall this thread from a few months back, but this idea for armor I
is the best I have heard. It is the two thin sheets of steel with an inner
honeycomb of insulation. The A and B panels are hooked to what amounts to be a
large capacitor, A is neg and B is pos, simple. When the bullet or RPG
penetrates from A to B an electrical discharge occurs and the round is vaporized
into nothing but a copper colored blemish and possible a small hole. British
invented it...pretty slick.

> Cost, extremely low, you are looking at nothing more than a large coil,
> powered by a conventional battery and generator system. 100% effective too
> against small arms.
>
> Jack

You are looking at a VERY BIG capacitor.

The latent heat of vaporization (amount of energy to turn liquid metal to
vapor) for metals is as follows:

Lead 8.7 x 10 E 5 = 0.87 million Joules / Kg
Copper 5 x 10 E 6 = 5 million joules/Kg

Assume a bullet weighs about 25 g (<1 oz):

Lead 0.87 x 10 E 5 x 0.025 = 21,750 joules
Copper 5 x 10 E 6 = 125,000 joules

A joule = 1 watt-second (1 watt for 1 second) so for:

Lead a 22 KW generator would provide enough power to defeat 1 bullet/ second
Copper a 125 KW generator would provide enough power to defeat 1 bullet/second.

In reality, the efficiency would be less than 50% requiring a generator many
times larger. Batteries are out of the question.

That's the physics, folks.

-John



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