Re: Tesla Coil toroid Size

To: tesla-at-pupman-dot-com
Subject: Re: Tesla Coil toroid Size
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Tue, 15 Sep 1998 07:06:14 -0600
Approved: terryf-at-verinet-dot-com

  Terry, Bart, All -

  I agree that measuring the TC input energy (power x time) would be
difficult. However, this test can be greatly simplified if a constant load
is used (controlled sparks). The advantage of a constant load in testing
any electrical apparatus is that the input conditions can be easily
correlated with the output conditions. The reason is because instantaneous
time does not have to be considered. Both the input and the output
waveforms are automatically averaged out. The overall losses are also
averaged out.

  If the test conditions are properly set up the power factor will be close
to 100 percent. The constant load (sparks) will be mostly resistive.

  For example if the input is 960 watts and the bks are 120 and the sparks
are 2 feet long then the TC is producing 8 watts per break (including
losses) and four watts per foot of spark. The effect of an existing
conductive path in the air and some other considerations like Vp and Ls,
etc, come into play, but this would at least be a start. This could then be
compared with the JHCTES computer program which is a watts to controlled
spark program.  
  JHC
--------------------------------

At 06:16 PM 9/14/98 -0600, you wrote:
>Original Poster: Terry Fritz <terryf-at-verinet-dot-com>
>
>Hi Bart, All,
>
>	I have never measured the input power of my neon power system (lazy) but I
>certainly do have the equipment to see what's there.  I suspect that there
>are high current pulses and all kinds of power factor variations going on.
>I notice that the variac vibrates with varying currents during sparking so
>I suspect the input power is very dynamic.  Probably far beyond any simple
>power meter and perhaps even beyond the abilities of my equipment.  What is
>needed is to record the current and voltage waveforms over time and them
>multiply them piece by piece to come up with a third power waveform over
>time.  Then one would have to average that waveform to come up with the
>average power.  However, that number may not mean much.  The real
>information is probably in the dynamic power vs. time waveform.
>Unfortunately, few off us will be able to measure this.  And if it is
>really messy, it won't be too meaningful.  
>	The problem with just a voltmeter and an ammeter is that you don't know
>the phase relationship between the two.  In the case of TCs, I bet that
>phase is wildly jumping all over the place as the output arcs twirl around.
> I also suspect that ouput arcs start to occur before the first notch
>quench so the output arcs are dirctly jerking the charging system around.
>	Perhaps I can get some time and give this all a try and post the waveform
>data.  Sort of high risk equipment wise (laptop + digital scope + TC = ??)
>but it should be interesting.
>
>	Terry Fritz