Energy levels was: DC power on Tesla secondary

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Peter, Terry, all,


I never really thought about it that way but you are absolutely correct.
Onlineconversions.com states that 1 nutritional calorie = 4186.8 joules.
Wow, 20 kJ would be a VERY small bite of a candy bar, like just under
5 calories! One of those single Life Savers candies is about 15 calories
or >60 kJ of energy! That's just about the same energy release of  one
of those July 4th "boom" mortars that Terry was talking about.
Also note that a nutritional calorie =  1000 laboratory calories and IIRC
this calorie is the amount of heat required to raise the temp of 1 gram of
water 1 degree celcius. Therefore a nutritional calorie will raise the
temperature of 1 kilogram (2.2 lbs) of water 1 degree celcius (1.8 degrees
Farenheit). So the bottom line is that even multiple kJ of capacitive discharge
does not really represent an impressive total amount of energy albeit the
manifestation of this realtively small amount of energy is quite impressive
when all released within a few micrseconds. The energy released from the food
we consume or the gasoline that we burn in our vehicles for that 
matter is released
at a much slower rate and therefore dosen't produce the "explosive" results
although it represents much more net total usable energy. I think someone
stated that although 1 joule released in one second and 1 billion joules
released in 1 nanosecond both represent the same total amount of
energy,  there would be a tremendous difference in the way that these
equal amounts of energy were released!

David Rieben


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Friday, August 12, 2005 9:59 PM
Subject: Re: DC power on Tesla secondary


> Original poster: "Peter Terren" <pterren@xxxxxxxxxxxx>
>
> 20kJ is also 20 AA batteries or a very small bite of a candy bar!
> http://www.phy.syr.edu/courses/modules/ENERGY/ENERGY_POLICY/tables.html
> But your points are well taken. However some of what you describe is 
> the product of a virtual short circuit spark.  Very nasty on the 
> caps and I hope I never mistreat them like that, particularly after 
> the transport cost of 130kg from the US to Australia.  (That cost 
> more than my car is worth but then again it is almost as old as the 
> Space shuttle and has done nearly as many miles).
> They are rated at 150 - 200kA.  At present my 1.5kJ can crusher runs 
> to 40kA in first 20us measured with my Rogowski coil.
> http://tesladownunder.com/misc1.htm#Measurement%20of%20high%20current%20pulses
> At the moment I use a tungsten contact in preference to a triggered 
> spark gap to try to minimise losses and noise for my can crusher. 
> With my current voltage reversal issues with can crushing I need to 
> be conservative with high energy discharges.
> I wasn't planning to enter the Darwin awards by putting a 
> screwdriver across the terminals of a 20kJ cap!
> I was sort of expecting to make a bunker for anything high energy 
> such as coinshrinking.  EMP and mains spike issues are certainly a 
> worry but I can pop these in a trailer and take them 'out bush' 
> (along with 20AA batteries to charge them).  There is also the local 
> rifle range. Neighbors are about 50 - 100m away and not in direct 
> line of sight so relatively distant compared to suburbia.
>
> Peter
>
> > Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>
> > A Gerret +P 44 caliber magnum round (about the max any normal human 
> > would fire from a hand gun) is about 2000 joules.
> > The original AK-47 round is 1400 joules.
> > The 30-06 round is about 3600 joules...
> > At say 10 feet, the "bang" from 20kJ would knock your right off 
> > your feet and probably unconscious!!!
> > Be careful, 20kJ is definitely in the "not at all funny" 
> > category!!  It is important to note the a 20kJ spark happens in 
> > microseconds so the energy effect is a giant shock wave.  The 
> > dropping car is spread out into a nice "soft" hit over tens of milliseconds...
> > For 20kJ sparks, you would have to be uncomfortably near so sand 
> > bags, very good ear protection, eye protection (very bright flash)....
> > .. Be careful there friend :-)  If you do set that thing off, try 
> > to get a tape video for us >:o))  But don't become a Darwin Award 
> > =:O  Bill's 7.5kJ thing blew up the electronics in three of his 
> > neighbor's houses too and much just from the "electrical" shock wave!!!...
> > Cheers,  Terry
>
> > > Take a compact car (1000 kg), rise it 2 meters, and drop it to the
> > > ground. This is 20 kJ.
> > > Antonio Carlos M. de Queiroz