Re: Joules per bang...

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hi Scot,

Tesla list wrote:

>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...
>
>anyway...   joules are best used in capacitor discharge systems and the 
>amount of time the capacitor is discharged
>
>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    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 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 pulsing 
>into the primary...    and at 675W per bang at 120 times a second...

Your pulsing 5.625 joules every 8.33ms, 675 joules over 1 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???

Math,
120 bps has already been accounted for in the 675 joule seconds energy 
term. You multiplied another 120 into the equation as though you were 
breaking at 14400 bps.

Take care,
Bart

>Tesla list wrote:
>
>>Original poster: "Luke" <Bluu-at-cox-dot-net>
>>I will happily bow out.
>>I will stop the complaining.
>>thanx
>>
>>Luke Galyan
>>Bluu-at-cox-dot-net
>>
>>-----Original Message-----
>>From: Tesla list [mailto:tesla-at-pupman-dot-com]
>>Sent: Saturday, January 17, 2004 6:01 PM
>>To: tesla-at-pupman-dot-com
>>Subject: Joules per bang...
>>
>>Original poster: Brett Miller <brmtesla2-at-yahoo-dot-com>
>>
>>Luke,
>>
>>Tesla list <tesla-at-pupman-dot-com> wrote:
>>
>>  >Original poster: "Luke"
>>
>>  >Thanx for the anaology since I don't have a grasp of the joules thing
>>I
>>  >will have to go figure it out. Guess im off on the next quest. :)
>>  >Can I ask why you say there is 7.5 joules per bang?
>>
>>E (Energy in Joules) = .5 * C (in Farads) * V^2 (Voltage Squared)
>>
>>Here's a piece of C source code you can compile in UNIX or Linux (using
>>gcc), dos (using bcc), or on Windows with Visual C++:
>>
>>/*
>>   * joules.c -- find joules (W-s)
>>   *
>>   *  Copyright (c) 2000, Eddie Kovelan and Sam Goldwasser
>>   */
>>
>>#include <stdio.h>
>>#include <stdlib.h>
>>#include <math.h>
>>
>>main()
>>{
>>    float E, C, V;
>>
>>    printf("\n \
>>     ******************************************************************\n
>>\
>>     *  This program finds the energy (J) stored in a capacitor (uF)  *\n
>>\
>>     *  at a specified voltage (V).                                   *\n
>>\
>>
>>******************************************************************\n");
>>
>>    printf("\nEnter voltage (V): ");
>>    scanf("%f", &V);
>>    printf("Enter capacitance (uF): ");
>>    scanf("%f", &C);
>>
>>    E = (.5 * C * (V * V));
>>
>>    printf("\nTotal energy in Joules (W-s) = %4.3f\n\n", E * 1e-6);
>>
>>}
>>
>>If you need help with understanding why the equation governs energy
>>discharge from a capacitor, consult a general physics textbook.  Hope
>>this
>>helps...I have to say though, it's somewhat funny to me when you ask for
>>
>>anecdotal information, then turn 180 degrees and complain about the
>>anecdotal nature of what you have been given.
>>
>>-Brett
>>
>>PS:  By the way.  I have used computer modeling to predict quantities
>>pertaining to both coil construction and coil behavior and found it to
>>be
>>strikingly accurate.  I have also done some calculations by hand on
>>paper
>>which tend to agree with the machine assisted calculations.  I don't
>>know
>>about the 1000 some odd lurkers on the TCML, but most of the active
>>members
>>are doing real science here.  I don't really see how your lemmings
>>analogy
>>fits in.
>>
>>Maybe I can get lucky and be successful in explaining what others on the
>>
>>list have tried an failed, attempting to get through to you.  The
>>"consensus" on the list that seems to bother you has come (especially
>>over
>>the last 5 years) in large part from painstakingly tedious emperical
>>research from experienced coilers....many of whom have significant
>>knowledge of engineering and physics.  No one is expecting you to take
>>anything on "faith".  All the emperical data you could ask for is here
>>in
>>the archives and all the experience in the world is waiting for anyone
>>who
>>is willing to stop yakking and actually do some coiling.  It's not that
>>I'm
>>trying to sound abrasive here, but it seems like a few times you've
>>complained about the list for some reason.  I'm going to call you on it
>>since I've been reading this list for over 5 years and have had the
>>priveledge of witnessing some of the greatest minds amateur science has
>>ever hosted.
>>
>>-Brett
>>
>>hot-streamer-dot-com/brett
>>
>>
>>  >Luke Galyan
>>  >Bluu-at-cox-dot-net
>><SNIP>
>>
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