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RE: FW: Re: Tesla Coil Efficiency Test
Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
Malcolm -
I remember those TC waveforms of yours. They were very important information
because there was so little TC data avilable in those days. However, as I
recall you said you had made tests but you did not show any calculations.
That is, calcs that included the overall energy in and energy out.
Your reply to Paul was about "transfer efficiency" and "spark loading" and
these are the subjects on which coilers do not agree. This is understanable
because of the difficulty of obtaining the proper test data. These are
conditions within the Tesla coil system (black box) and making tests require
considerable skill and instrumentation. The black box (lamp) test I show is
a very simple test that any coiler can do to determine the efficiency of his
coil. Details of what goes on within the black box are not required. As I
pointed out in another post the accuracy is better than that obtainable by
other tests.
The black box test is a standard type of test in engineering to determine
the overall efficiency of an electrical device or system. However, I see
that there may be one problem when it comes to Tesla coils. In my example of
how I tested and found the efficiency of one of my coils I included the
coupling factor. Should the coupling factor be included to find the TC
efficiency with the black box test?
John Couture
--------------------------------------
-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, June 19, 2002 9:36 PM
To: tesla-at-pupman-dot-com
Subject: RE: FW: Re: Tesla Coil Efficiency Test
Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<m.j.watts-at-massey.ac.nz>
Hi John,
On 19 Jun 2002, at 9:03, Tesla list wrote:
> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
>
>
> Malcolm -
>
> The efficiency determined by the incandescent lamp method is a continuous
> output not a single transfer. The efficiency for the single transfer or
> spark type of test is where there is no consensus by coilers. One of the
> many problems with the single transfer is relating the output energy to
the
> input energy when operating at multiple breaks per second.
>
> How did you measure "both conditions?" to arrive at
> energy out/energy in = .80?
I outlined the method of measuring transfer efficiency in a reply to
Paul Nicholson. The other condition (attached spark loading) was easy
to see on the oscilloscope. I actually photographed a trace of a coil
doing this, sent it to Richard Hull and I believe you may have
obtained a copy from him. This is all old ground.
Multiple BPS is no problem - the high efficiency figure applies
when the coil connects to a grounded object and stays connected over
a number of breaks (for a second or more for example).
Regards,
malcolm
> John Couture
>
> ------------------------------------
>
>
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Tuesday, June 18, 2002 3:43 PM
> To: tesla-at-pupman-dot-com
> Subject: RE: FW: Re: Tesla Coil Efficiency Test
>
>
> Original poster: "Malcolm Watts by way of Terry Fritz
<twftesla-at-qwest-dot-net>"
> <m.j.watts-at-massey.ac.nz>
>
> Hi John,
> I have to take issue with your last statement:
>
> On 18 Jun 2002, at 7:37, Tesla list wrote:
>
> > Original poster: "John H. Couture by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> >
> >
> > Malcolm,
> >
> > You are right that this thread will go nowhere if we are talking about
TC
> > spark outputs because this has been discussed in the past with zero
> results.
> > The reason I brought this matter up again was because I felt a resonable
> way
> > to look at the Tesla coil would be as an electrical device that could
> > produce a useful energy output in the form of light. The efficiency
could
> > then be determined by what I called the "black box" method. I show how I
> > made this test for one of my coils in one of my books. The efficiency
> would
> > be
> > efficiency = useful energy out/input energy
> >
> > The coil details did not have to be known, only the input and output
data
> > was necessary. Any size classical coil could be used for this test. If
> the
> > coil was properly designed and tuned the efficiency would likely be
about
> > 85% for coils under 15 watts input and for coils over 15 watts
> > efficiency = 1/(log(input watts))
> > The equation may have to be changed if indicated by tests.
> >
> > A 1000 watt input coil would be about
> > efficiency = 1/(log(1000) = 33%
> >
> > It is very obvious that if spark outputs are used finding the TC
> efficiency
> > would require much more work and agreement on details by coilers.
However,
> > we can probably assume that the maximum efficiency for the lamp load
type
> of
> > test is the maximum efficiency for the spark load until proven
otherwise.
>
> I cannot agree and here's why: We *know* that efficiency for a single
> transfer can easily be made to exceed 80%. At ringup time there is
> virtually no loading of any kind on the coil. If that energy then
> gets dumped into an attached spark and drains the secondary before a
> further trade back to the primary can occur, the 80% figure stands. I
> *have measured* both conditions occurring in more than one coil.
> Imposing a steady load on the secondary prevents it from absorbing
> all primary energy before the energy is passed to the load. If the
> secondary is loaded to criticality, transfer time is prolonged and
> the gap loses more power. QED.
>
> Regards,
> Malcolm
>
>
>
>
>
>
>