Confirming the Delayed Lenz Effect

[MileHigh]

Magluvin:

Note the resistance test for the coils is a DC test.  It can't be "fooled" by any arrangement of coil connections.  So he is clearly working with coils of two different lengths and number of turns.

Im not sure where you are getting that 1 coil has more turns than the other as those are the first talking points as to each coil having the same amount of copper and the same amount of 'total' turns, just wired differently. But by visual inspection should look identical except for the connections at the ends. The increase in capacitance, as Tesla has stated in his patent is that the capacitance 'neutralizes' the self inductance of any given current that may be employed. So thats why the inductance measured lower.

In theory it's possible but highly unlikely, perhaps if the inductance meter is poorly designed.  The thing to keep in mind is that in a coil, the inductance is millions of times higher than the capacitance in relative terms.  The capacitance is like a fly siting on an elephant which is the inductance, even with a pseudo-bifilar configration.

What happens in the time domain when you go to energize a coil that also possesses some capacitance?  The capacitance charges up nearly instantly, because that's what capacitors do.  Then the inductance takes over for a long time.  It's the old flywheel effect.  The current climbs in slow motion relative to the zippy capacitance current.  The inductance meter reads that, the slow current climb due to the inductance, it's doesn't read the minuscule capacitance and it's associated minuscule current which has almost no affect on the real operation of the inductor.

I haven't read too much about Tesla so I can only guess what he was up to with these kinds of coils.  It's possible that capacitor technology at the end of the 19th century was barely starting so he was improvising.  Perhaps Tesla had these very large coils 10 feet high and he experimented with the interleaved coil winding to use these giant coils as a energy storage device - a giant LC resonator.  If you can imagine putting 100 amps through a giant coil and then disconnecting the DC feed, then the coil would self-resonate for x seconds.  With the inductance being so large and the capacitance so small, the voltages generated across the self-resonating coil would have been very high.  You can go to a coil calculator site and calculate the inductance for a giant coil.  Then make up a very small capacitance value.  Assume the resistance of the coil is quite low.  Then go to an LC resonator sim site and punch in the numbers and see what happens.  As the capacitance value gets lower the peak voltage will go towards millions of volts.

MileHigh

[MileHigh]

Farmhand:

I didn't even know that there were sim sites that would give you an associated capacitance for a given inductor geometry.  You learn something new every day as they say.

MileHigh

[Magluvin]

Magluvin:

Note the resistance test for the coils is a DC test.  It can't be "fooled" by any arrangement of coil connections.  So he is clearly working with coils of two different lengths and number of turns.

In theory it's possible but highly unlikely, perhaps if the inductance meter is poorly designed.  The thing to keep in mind is that in a coil, the inductance is millions of times higher than the capacitance in relative terms.  The capacitance is like a fly siting on an elephant which is the inductance, even with a pseudo-bifilar configration.

What happens in the time domain when you go to energize a coil that also possesses some capacitance?  The capacitance charges up nearly instantly, because that's what capacitors do.  Then the inductance takes over for a long time.  It's the old flywheel effect.  The current climbs in slow motion relative to the zippy capacitance current.  The inductance meter reads that, the slow current climb due to the inductance, it's doesn't read the minuscule capacitance and it's associated minuscule current which has almost no affect on the real operation of the inductor.

I haven't read too much about Tesla so I can only guess what he was up to with these kinds of coils.  It's possible that capacitor technology at the end of the 19th century was barely starting so he was improvising.  Perhaps Tesla had these very large coils 10 feet high and he experimented with the interleaved coil winding to use these giant coils as a energy storage device - a giant LC resonator.  If you can imagine putting 100 amps through a giant coil and then disconnecting the DC feed, then the coil would self-resonate for x seconds.  With the inductance being so large and the capacitance so small, the voltages generated across the self-resonating coil would have been very high.  You can go to a coil calculator site and calculate the inductance for a giant coil.  Then make up a very small capacitance value.  Assume the resistance of the coil is quite low.  Then go to an LC resonator sim site and punch in the numbers and see what happens.  As the capacitance value gets lower the peak voltage will go towards millions of volts.

MileHigh

"In theory it's possible but highly unlikely, perhaps if the inductance meter is poorly designed.  The thing to keep in mind is that in a coil, the inductance is millions of times higher than the capacitance in relative terms.  The capacitance is like a fly siting on an elephant which is the inductance, even with a pseudo-bifilar configration."

When you say 'pseudo', what does that imply exactly?  Yes the capacitance of a coil is very tiny indeed. But the series bifi increases it dramatically in comparison to a normal coil. And the more turns in the series bifi, the more capacitance, where as a normal coil, the capacitance becomes less with more turns.

"What happens in the time domain when you go to energize a coil that also possesses some capacitance?  The capacitance charges up nearly instantly, because that's what capacitors do.  Then the inductance takes over for a long time."

Yes!  Being that the series bifi has much more capacitance, the series bifi charges up more and quicker, being that the larger internal capacitance neutralizes the self inductance.

"Assume the resistance of the coil is quite low.  Then go to an LC resonator sim site and punch in the numbers and see what happens.  As the capacitance value gets lower the peak voltage will go towards millions of volts."

Is there a calculator for series bifilar coils?  As they have a different nature. Trying to read them with meters give erratic results as compared to a normal coil.

Mags

[Magluvin]

I haven't read too much about Tesla so I can only guess what he was up to with these kinds of coils.  It's possible that capacitor technology at the end of the 19th century was barely starting so he was improvising.

http://www.free-energy-info.com/TeslaPatents/US0512340.pdf

Its only 2 pages of description. 

Mags

[MileHigh]

Final comment about an inductor with an associated capacitance.  How does it respond in the frequency domain?

We know that as you sweep the frequency higher, the inductor will show an increasing impedance.  As the frequency tends towards infinity, the impedance of the inductor tends towards infinity.

What happens is that above a certain high frequency, the very small capacitance starts to take over.  So above a certain frequency the impedance of the inductor starts to drop, and it will tend to go towards zero as the frequency tends towards infinity.

The converse applies to capacitors, as the frequency tends towards infinity, the small inductance associated with the capacitor starts to take over, and the impedance tends towards infinity.

(I am simplifying in the examples above to keep it relatively simple.)

Those are basic nuts and bolts to keep in mind.  The example that most will relate to is the gate capacitance for a MOSFET.  At very high frequencies, power can pass through the MOSFET via the gate capacitance because the impedance is very low.  That can screw up very precise measurements at high frequency.

MileHigh