Re: DC power on Tesla secondary (was 20 joules at 100 bps vs 4 joules at 500 bps)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Steve,

At 06:05 AM 8/14/2005, you wrote:


> > A Gerret +P 44 caliber magnum round (about the max any normal human 
> > would fire from a hand gun) is about 2000 joules.
>
> I hope this is not too off-topic, but is that kinetic energy of the 
> bullet? chemical energy in the propellant? or what?

Kinetic energy of the bullet.  I assume it takes a lot more to get it 
out the barrel.  I think you can find out how much powder they use 
(330 grain), but I don't know the conversion:

http://www.garrettcartridges.com/products.asp

These bullets can only be used in super heavy duty handguns since 
they will blow many handguns to pieces...  One fellow stopped an 
attacking Grizzly bear at 15 feet...  it is as close as you can get 
to a hand held "cannon" at close to 65,000 PSI...  There is a big 
fire ball about 10 to 20 feet beyond the barrel...   That's "2000" joules...


> The biggest bang I ever got (apart from that time I snipped through 
> a live 240v extension cord with wire cutters) was when my old DRSSTC 
> blew up. When an IGBT shorts out, it causes a huge shoot-through 
> that makes the other device in that arm fail short too. Then the DC 
> link capacitor bank discharges through both devices, vaporising them 
> and scattering pieces all around the shop.
>
> My setup had a "Rupture energy" of only about 200J but it still 
> scared the heck out of me and the spectators. It was sparking away 
> great style and the next second its innards were strewn around the 
> floor with a huge flash and bang! I found pieces of transistor about 20ft away.
>
> Larger coils, like industrial motor drives and traction inverters, 
> can have rupture energies comparable to the rounds of ammunition 
> Terry was talking about. But I've never seen an electronic engineer 
> working on one live with a flak jacket! I guess they are designed 
> _not_ to launch sharp pieces of metal at supersonic velocities.

We have blown some pretty big stuff.  But it is all pretty "safe" and 
designed to explode nicely.  The loudest was big UPS inverter fuses 
into a dead short...  They guy working on it could not do much else 
the rest of the day but sit there and tell use how loud it all 
was...  I don't know the energy...

A lot depends on how fast and what air pressures are developed.  But 
sparks are good at both those.

It is safe to say that a cap charged to 20,000 joules is one serious BANG!!!

Cheers,

        Terry



> Steve Conner