Re: Joules per bang...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Mddeming-at-aol-dot-com 

Oops Scott,
     I appreciate your trying to clear up the explanation, BUT I'm afraid 
your imprecise use of terminology may have confused things worse than they 
were to start with. (see Below)

In a message dated 1/18/04 9:36:27 PM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:
Original poster: BunnyKiller <bunikllr-at-bellsouth-dot-net>

dont give up on the joules thing quite yet    it took me a few moments to
figure it out too...

A joule is an amount of energy, a Watt is a unit of power. Power is the 
RATE at which energy is released.

anyway...   joules are best used in capacitor discharge systems and the
amount of time the capacitor is discharged

Joules are best used anywhere you want to talk about energy.

to find joules,  the (C X Vsquared)/2 gives you joules

(.002 X 1,000,000)/2 = 1000

example    2000uF -at- 1000VDC  =  1000J     now if the cap is discharged
during a time duration of 1 second it will produce 1000 watts of
energy

1000 watts of POWER, same 1000 Joules of ENERGY!
now here is the awesome thing...  say you dump that charge into
a load in under ...  lets say...  .0001 seconds....   the pulse power in
watts is 10 megawatts...   yuppers  10 million watts of energy

10 million watts of POWER, same 1000 Joules ENERGY!
at a
pulse... but it only lasted 1/1000 of a second...  no wonder why the wires
evaporated  ;) ...  no wonder why coin shrinkers work...  :)

soooo...   in effect, ( more to real life for coiling)  you have 15KV in a
.05 uF cap with a gap firing at 120Hz....

this gives    5.625 J per bang     (considering that the cap is fully
charged at  firing of the gap)   you should have 675W of energy

5.625 Joules of energy, at a RATE of 675 Watts (power). Watts are Joules 
per second.
pulsing
into the primary...  and at 675W per bang at 120 times a second...
thats  81KW per second....   sooooo   either we arent getting full charge
on the caps or my math is terrible....  this raises a new
question....  anyone have an answer???

     "Watts per bang" is a meaningless quantity. The dimensions of this 
"quantity" would be joules/sec/bang, so, joules/sec/bang X bangs/sec = 
joules/sec^2. Your "81 kW per sec." would be a rate of change of the rate 
of energy transfer. (or maybe joules per square second???)
  You still have:5.625 Joules/bang X 120 bangs/sec = 675 Joules/sec. = 675 
Watts. Arbitrarily multiplying numbers together is good arithmetic, but 
meaningless math and bad science.

Scot D

Matt D.