RE: FW: Re: Tesla Coil Efficiency Test

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

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
> 
> 
> 
> 
> 
> 
>