More Mini Coils
From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: Thursday, June 19, 1997 2:45 PM
Subject: Re: More Mini Coils
Hello John, all,
> From: John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
> Sent: Wednesday, June 18, 1997 9:53 PM
> To: Tesla List
> Subject: Re: More Mini Coils
> At 07:48 AM 6/18/97 +0000, you wrote:
> >From: Greg Leyh[SMTP:lod-at-pacbell-dot-net]
> >Sent: Tuesday, June 17, 1997 11:55 PM
> >To: Tesla List
> >Subject: Re: More Mini Coils
> >Robert W. Stephens wrote:
> >> Not to rain on your parade or anything but I just have to correct
> >> you. What Malcolm achieved was most definitely *NOT* 60 watts per ft
> >> of discharge. He reported producing some 4 inches of discharge for
> >> 20 watts input.
> >20W / 4in = 60W/ft by my calculation. Remember, the unit W/ft is not
> >a length, but is rather a ratio used to determine coil effectiveness.
> >> As we (that have actually gotten our hands dirty and
> >> built coils that is, and I'm not saying you haven't) know well, the
> >> ratio between input power and output spark length is far from linear.
> >> Streamers issuing from a topload terminal seem to crave increasing
> >> power at an exponential rate to their length.
> >All too true :^< Perhaps a more direct measure of coil effectiveness
> >would be to normalize the W/ft ratio to operating power level.
> >None the less, Malcolm's 'little wonder coil' does provide an
> >interesting data point, in a sparsely populated area of tesla coil
> >parameter space. Way to go, Malcolm!
> All -
> Was that a controlled spark length? Watts per spark length for the same
> coil can vary greatly depending on who does the measuring. Maybe someday
> coilers will agree on how this important TC parameter should be determined.
Dear me. I obviously haven't been entirely clear on this. You know
what a high-powered attached discharge looks like, right? Well that
is exactly what I have consistently got with the system in question.
There is no leeway for error. I am talking point-point! If you don't
believe me, reproduce the experiment. You have all the data necessary.
I am not into giving all my hard work away, but on this occasion, I am
observing the rules applying to verification because I didn't
photograph the result. I doubt whether anybody is going to measure 4"+
any differently from myself.
> Keep in mind that the secondary terminal can be charged by more than one
> break/charge before it will discharge. In that case the wattage per spark
> length is doubled or tripled etc. per spark!
Personally I say that is completely wrong. I would like to see a
substantive proof of that statement. I scoped this system running. The
secondary duty cycle was no more than 5%. It was completely quiet for
the bulk of the time between gap fires. This is no different to any
other system I've scoped either.
> Note, also, that the primary capacitor can never be charged to more than
> the source voltage by increasing the input wattage. Why does increasing the
> input wattage hopefully increase the secondary voltage if turns are not
> involved? Vs = Ls di/dt is not resonance.
You increase the BPS if your quench allows it. This is exactly what I
achieved by closing the gap up. Power input was constant. It was the
extra ionization at a lower output voltage which allowed the
streamers to coalesce into a single channel.
> How should the input wattage and the power factor be measured for the
> surges of input current?
> After many years of research I am still pondering these TC questions.
Best of luck.