Tesla's "COIL FOR ELECTRO-MAGNETS".

[synchro1]

The self capacitance of the "Tesla Series Bifilar Coil" helps stabilize the LC tank. The ability of this kind of coil to completely free itself of reactance at high frequency resonance is another topic under discussion in this thread, I feel the subject is in the right area. 


I think this is much easier to succeed at then most people think, and that any dipole magnet, series bifilar power coil pulse motor, can be rigged to self run just by synchronizing the R.P.M to your pre calculated tank frequency. I also think the "Sine Wave Tank" motor will run with the battery removed if the circuit is Earth grounded.

[jbignes5]

From what I know , the magnets blew out the spark like using compressed air, etc. Probably like in a glass television picture tube, the deflection coils can bend the electron beam. So when the cap voltage gets to be enough to jump the gap, as the spark discharges the cap, the stream of electrons is pulled and pushed from its straight path from electrode to electrode due to the srong magnets. Maybe the magnets bend the path enough that it stops due to too great a distance as the bend grows . Also probably cutting off the spark well before completely discharging the cap.

Tito once told me in pm that, yes, he uses a zener as a spark gap.  So possibly putting it all together here, we would need a rectifier diode in series with a reverse biased zener(probably high voltage), in which the rectifier diode forces the one way street and the zener stops conduction from the cap at a particular voltage level. One more item would be needed. A timed/voltage controlled  switch in series with the diode and zener. The trigger level to turn on the transistor would be what ever voltage that is higher than the zener voltage that you desire. This would effectively produce a disrupted discharge. Say the trigger turns on the transistor at say 300v, and the zener cuts it off at 250v. Just an example. The transistor should stay on after trigger voltage is met, possibly also  triggered off when the zener cuts out. Would have to be worked out.

I dont believe that the magnets at the spark gap act as a rectifier.  I believe a spark could happen in either direction, just the bending would be opposite. So the idea of the abrupt cutoff is to stop current in one direction abruptly without any possibility of continued current flow from the cap to the load/coil, like a reed switch allowing current to continue to flow across the spark between the open contacts. And once the cap has lost some charge from an abrupt discharge, the voltage is not high enough to breach the gap, so no chance of refire till the caps voltage reaches breaking point.  In the zener gap model, the switch would be triggered by a preset breach voltage level sensor from the discharge cap. Probably better than trying to use a timer and tune to operating freq.     And the switch,transistor needs to be turned off just 'after' the zener makes the break in current flow. This way the switch/transistor is protected from possible spikes, that tend to burn transistors.


Mags

I haven't started messin with the spark gap thing yet. I need to move myself to a more remote area and start working in my new lab. What I can report is that Tesla knew this was a better way to get an abruptive spark and that it's effects were much smoother, like in the displays he designed to look at these discharges. He also found that the spark gaps robustness was far superior to other methods. In the lecture he describes the effects going from a larger wire circle to a ball electrode. He found that going into a smaller inner surface tended to intensify the discharges going to the center electrode. He talks about the discharges as being unusually smooth and had a better uniformity that he had never seen.


As for syncro's statements I have to agree. The bifilar seems to be worthy of our study. Think about the increased capacitance alone makes this something special. Built in capacitance inside the coil itself. We know about lcr circuits but this changes things a bit, especially when it is series bifilar.

[Bob Smith]

As for syncro's statements I have to agree. The bifilar seems to be worthy of our study. Think about the increased capacitance alone makes this something special. Built in capacitance inside the coil itself. We know about lcr circuits but this changes things a bit, especially when it is series bifilar.

Is the uniqueness of the swbf coil perhaps due more to its interaction with the dielectric medium than has been acknowledged?
The dielectric is essentially an all pervasive reservoir of stored charge.  That is, a kind of all pervasive capacitance that is constantly discharging and replenishing everywhere.
In the swbf coil we have mutual cancellation of magnetic fields between windings and accompanying minimization of current; we also have accompanying rise in voltage output and raised capacitance between windings.  But at the same time, we also have the interaction of bemf in oppositely-wound coils.

So, while we have concentrated magnetic attraction between windings, we also have interaction of bemf forces between windings.  This means the forces between windings are also coextensive with the dielectric medium - a kind of entry point for the dielectric to rush in to a circuit. 

So yes, the swbf coil acts like a capacitor, a step-up voltage transformer of sorts, but also an entry point for greater interaction between the dielectric medium and circuit.
Might this interaction with the dielectric be part of this coil's magic that made it so important to Tesla?
Bob

[sparks]

  It appears to me that the capacitance developed between the adjacent conductors supplies the capacitance needed to match the inductance of the coil without introducing external capacitors.  Old radio transmitters and receivers had a huge problem with capacitors aging.  If the sets sat around for a long time inactive the dielectric coatings on the foils used would change and the capacitors would go far off range.   Circuits had to be utilized to strip and redeposit the dielectric.   Tesla developed the coil because of the problems with lumped components.  There are no buss losses either between inductor and capacitor.   I believe he used the coil as an oscillator.  The spark gap acts to introduce power into the oscillator.  The magnetically quenched spark gap is used just like the blowout coil on a dc circuit breaker.  As soon as current flows through the quenching coil it magnetically blows out the plasma in the gap before the supply capacitor dumps all it's charge.  The coil rings down until the electric field between electrodes in the gap causes the air to ionize into a plasma.   The electrolytic capacitors mentioned above used boron and water.  The electrolyte extends one of the plates electrically to the solid dielectric film of one plate.  There ions are attracted to the cathode and remain there after the voltage is removed from the capacitor.  This keeps the electrons in the cathode plate allowing for the storage of the potential applied.  So in a way the coil for electromagnets acts as a dynamic capacitor.   It stores the energy of each supply capacitor discharge in the oscillations of energy between magnetic field and electric field within the geometry of the coil.

[Farmhand]

Is the uniqueness of the swbf coil perhaps due more to its interaction with the dielectric medium than has been acknowledged?
The dielectric is essentially an all pervasive reservoir of stored charge.  That is, a kind of all pervasive capacitance that is constantly discharging and replenishing everywhere.
In the swbf coil we have mutual cancellation of magnetic fields between windings and accompanying minimization of current; we also have accompanying rise in voltage output and raised capacitance between windings.  But at the same time, we also have the interaction of bemf in oppositely-wound coils.

So, while we have concentrated magnetic attraction between windings, we also have interaction of bemf forces between windings.  This means the forces between windings are also coextensive with the dielectric medium - a kind of entry point for the dielectric to rush in to a circuit.

So yes, the swbf coil acts like a capacitor, a step-up voltage transformer of sorts, but also an entry point for greater interaction between the dielectric medium and circuit.
Might this interaction with the dielectric be part of this coil's magic that made it so important to Tesla?
Bob

Bob, The coil for electromagnets or ( a bifilar wound then series connected coil) does not have "mutual cancellation of
magnetic fields between windings and accompanying minimization of current".

The windings are in addition configuration not cancelling, if the winding are connected to cancel each others magnetic fields then
the coil is connected oppositely to how it is connected in the patent, and if connected in cancelling mode the coils when
connected will read very close to zero inductance.

Coils connected in cancelling mode have no place in this thread.

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