Self accelerating reed switch magnet spinner.

[MileHigh]

Synchro1:

I still hold my view that the series bifilar coil is much ado about nothing.

Take the example of TK's clip.  If he had a second linear-wound coil made with the same wire and the same number of turns then the inductance meter would show the same reading.  So that means you are left with the minuscule capacitance in he series bifilar coil to show a "difference."

So imagine you have the two coils as per TK's clip, one regular and one series bifilar with the same build and materials, etc.  Run those two coils through a series of tests, LC resonance, self resonance, series choke, pulse response and related L/R time constant and you will be very hard pressed to see any significant differences at all.  At least that is what I believe when I crunch the two coil configurations in my head.  For the series bifilar I crunch a measurable inductance interacting with a minuscule and nearly insignificant capacitance and that's what I get.  The minuscule capacitance is simply blown away by the effects due to the inductance.  Sort of makes sense, don't you think?

Unfortunately I am not set up to do any testing.  Until I see someone do those tests it's all just talk and speculation on both sides.  However, I have explained my rationale for my statements in detail in the past.

Suppose you do the A-B comparison test and see nothing remarkable at all, the coils look and act almost the same.  So then what are your thoughts?

Then you could extend the tests to a pancake series bifilar coil, the "true Tesla coil."  Will you see significant differences from what you see above?  My guess is you will see some frequency response differences, but in the overall scheme of things they won't really and truly mean much.

I am just giving you a simple, rational analysis as I see it.  Others may have differing opinions.  Someone can run some good tests if they want to and that would answer a lot of questions.

Your far out claims about the series bifilar coil are still far out.  To put it in context, the "wondrous properties" of the series bifilar coil as it is interpreted around here are never discussed in the real world of electronics and engineering.  The concept doesn't even exist.

MileHigh

[synchro1]

@Tinselkoala,

"Tesla explains that a standard coil of 1000 turns with a potential of 100 volts across it will have a difference of .1 volt between turns. A similar bifilar coil will have a potential of 50 volts between turns. In that the stored energy is a function of the square of the voltages, the energy in the bifilar will be 502/.12 = 2500/.01 = 250,000 times greater than the standard coil!"


How can anyone generate the same kind of potential between the windings of a single wire coil with the addition of a capacitor? You can't duplicate the performance of the Tesla pancake that way. A single wire coil doctored by you can never work as well without the potential of the Tesla pancake on JLN's hotplate. I still challenge you to a bet. 


Coil type D below, a series bifilar, produces more magnetisem:  

[conradelektro]

Looking at the drawing synchro1 posted (the Tesla coils type A to D) I wonder if one can measure the values given there with a good LCR meter?

Santa Clause will bring me this LCR meter http://www.bkprecision.com/downloads/datasheets/87xB_datasheet.pdf

So, my question: Once I wound the "synchro coil" I will be able to hook it up to form any of the four types A to D from the drawing synchro1 posted.

Is it possible to measure directly L (Henry) R (Ohm) and C (Farad) of this coil with my new BK-879B (with no additional electronics and without destroying it)?

And if I wind a similar coil (same size, about the same number of windings) with just one wire, I think I can lay to rest the whole theoretical discussion in what way bifilar coils are better than ordinary coils.

Please give me advice. I only believe in measurements, words are just words.

Greetings, Conrad

[gyulasun]

Hi Conrad,

Very nice and useful-looking LCR meter indeed, its switchable test frequencies are an advantage.
Trying to answer the questions,

1) yes, your meter is supposed to measure the 'coil' types A to D, mainly for their DC resistance and inductance.
2) yes, your meter should measure directly the L and R  values of a coil, no need for additional electronics and you cannot distroy it .

Notice:  the C capacitance of  'coil' types A and B and D cannot be measured with this meter, and not with many other LCR meter, it needs a different measuring method than these meters use.  I think, you can measure the capacitance between the two bifilar coils in coil type C but of course in this case there is no L meter possibility because the meter will sense 'coil' type C as a capacitor.

There is a 35 minute demo video on your meter: http://www.youtube.com/watch?v=H4TP0i917Ro 

Merry Xmas to you all!

Gyula

[conradelektro]

@Gyula: thank you for the explanation, that helps.

I searched a bit for "parasitic capacitance of a coil" and found this measurement method:

http://forum.allaboutcircuits.com/showpost.php?p=50941&postcount=6

http://en.wikipedia.org/wiki/Parasitic_capacitance

I have a signal generator, so in principle I can do it. But the bifilar coil next to the spinning magnet will only receive rather low frequencies (20 Hz = 1200 rpm to 100 Hz = 6000 rpm) and the parasitic capacitance could be ignored.

All these people talking and writing about Tesla coils (pancake, bifilar, ..), have they ever done some real measurements?

Greetings, Conrad