RE: NST power test

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

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi John,

I have been doing tests too :-))  Although still very rough draft like, it 
is at:

http://hot-streamer-dot-com/temp/NSTva.html

It is not done yet, but I thought I would mention it now for 
suggestions.  I could only get 260VA out of a 360VA NST using just 
caps.  Any ideas are welcome ;-))  It is all set up and just waiting.

Cheers,

         Terry

At 11:43 AM 1/15/2003 -0500, you wrote:

>To All -
>
>In the Richard Hull report mentioned below the author proved his point by
>doing the tests and producing a graph. However, how many coilers mistakenly
>assumed the graph shown was for a Tesla coil load? The graph was actually
>only for a resistive load connected to a neon sign transformer (NST). It
>should be noted that a Tesla coil load on a NST is primarily a capacitive
>load, the TC primary capacitor. The spark gap is a controllable resistance
>load.
>
>Several years ago I made tests and graphs for combinations of resistors and
>capacitors connected to NSTs. The results were very infomative and showed
>why the length of the streamers could vary so greatly from TC to TC using
>the same wattage input. It was basically a matter of power factor in the NST
>secondary (not NST primary) circuit. Very few coilers are aware of this
>condition. The power factor in the NST secondary circuit can be easily
>changed by changing the resistance and capacitance in the tests.  In other
>words the combination of resistor and capacitance load on the NST secondary
>are the main variables that determines the streamer length for the Tesla
>coil. Higher power factors in the NST secondary circuit (Tesla primary
>circuit) mean longer streamers. This has nothing to do with resonant
>charging.
>
>In fact every coiler should make these tests and learn why tesla coil
>operation is so difficult, probably impossible, to predict with calculators
>and simulators. For example the tests show how the VA output of the Tesla
>coil can be greater than the VA input. Conditions like this have a direct
>effect on the streamer length. These tests are easy to do in the workshop
>with a NST, resistors, capacitors and the proper instrumentation. To apply
>this knowledge with a TC operating at high voltage is very difficult. The
>coiler usually only sees a difference in the streamer length when tweaking
>the coil not knowing exactly what is happening in the TC system.
>
>Some day I hope to make a report with graphs of these tests. However,
>coilers can do their own tests now and write their own report.
>
>John Couture
>
>-------------------------------
>
>
>-----Original Message-----
>From: Tesla list [mailto:tesla-at-pupman-dot-com]
>Sent: Tuesday, January 14, 2003 3:01 PM
>To: Jon Rosenstiel
>Cc: tesla-at-pupman-dot-com
>Subject: Re: NST power test
>
>
>Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
>
>Hi Jon,
>
>Very nice report!!  I noted on the fusor list that Richard wanted it passed
>on, so I will copy the Tesla list too.  Please give Richard our best!!  You
>may also mention that the posting record here is only like 130 posts per
>day, so far :o)))
>
>Of course, if one were to depot the NST and remove the shunts, then maybe
>it would have a much more stable output suitable for a power supply.
>
>I am also going to do a resonant test in the next few days that may have
>limited applications as a power supply too if the load is stable.  I am
>hopping to study SLTR effects more to get far more power out than the NSTs
>VA rating ;-))  Definitely bleeding edge stuff there, but I have some weak
>transformers I can use for this nasty testing ;o))
>
>Cheers,
>
>          Terry
>
>
>At 11:18 AM 1/11/2003 -0800, you wrote:
> >Hi Terry, thought I'd pass this along.
> >
> >Richard Hull performed an output voltage vs. output current test on a
>couple
> >of NST's, and wrote it up in a nice report. He posted his report in the
> >"files" section of the fusor forum.
> >
> >You can find it here: http://www.fusor-dot-net/board/index.php?bn=fusor_files
> >
> >Regards,
> >Jon