My first WFC/VIC

[fritz]

I have an automotive car coil. I have tested a car ignition coil and it won't even put forth a spark across a 1/16" air gap when pulsing it with DC 12 volts. I'm guessing it is around 10 times weaker without using a capacitor to discharge it. The rapid discharge on the negative side of the coil obviously creates the huge spark. When I hook the same coil to a spark module, I get a 1" long spark in open air that is loud and blue. Anyway my point is, I might be able to use this car coil as a transformer, so long as I don't use a capacitor to discharge the coil. It should lower the output dramatically and I can still produce enough power by reducing the voltage to 10 volts input. It may or may not work at all, but it will be good to experiment with.

An ignition coil uses back-emf for firing.
As already laid out - the coil is charged (some energy in)
and wants to keep its current (current induces magnetic field - magnetic field induces current) - like an inertia.

If you think about mechanics - braking soft means less forces - braking (against wall) - high energy.

Same with back emf. The faster you turn off the current in the coil from Imax to 0 - the higher voltage you get.

Electronic ignition can turn off way faster than ignition with breaker points (little spark, plasma).

I have seen some day an ignition with breaker points which "formally" functioned - but the way on how the current was switched off was so "soft" - that there was pretty less hv comming out.....

conclusion/fact: Top back-emf voltage depends on coil _AND_ time (speed) of switching off.
This is the reason why you should use _FAST_ diodes and _FAST_ mosfets and _FAST_ switches if you want to maximize back-emf.

[fritz]

The only real diagram of a choke besides vague circuit descriptions along with light illustrations other than this diagram below. What it looks like to me is the coil is wound in a resistive non-inductive type winding where the flow of current is in opposite directions canceling out the magnetic field. If this is the case, why use a core? I have seen this style wind in other devices like Tesla coils but not multi-layered like Stan's as shown in the "Independent Study". I wouldn't even think you could get a step charging effect with such a coil. Does a non-inductive coil cause a voltage drop like a resistor does?

I would say the compensation of the magnetic field (non-inductive) will only work if both bifilar coils "see" the same voltage (at the same time) - means carry the same current (at the same time).
This would only work if the coils are connected with 0 ohms at both sides.

In this case you have the WFC in series - even if there is the same current at the same time - there is a different voltage on both coils (at the same time).

->The (overall) inductance of the coil depends on the impedance of the WFC. If you short-circuit the WFC - no inductance (canceling) (...)

So there is an effective (very high - depends on length) inductivity - and as long as the energy you pulse in is higher than the energy which drains out - there will be a stepchargin effect.

[fritz]

@HeairBear (Hi !)
Do you have the picture you posted from the cluster array in a better resolution - or can post a link ?

rgds.

[fritz]

I would say the compensation of the magnetic field (non-inductive) will only work if both bifilar coils "see" the same voltage (at the same time) - means carry the same current (at the same time).
This would only work if the coils are connected with 0 ohms at both sides.

In this case you have the WFC in series - even if there is the same current at the same time - there is a different voltage on both coils (at the same time).

->The (overall) inductance of the coil depends on the impedance of the WFC. If you short-circuit the WFC - no inductance (canceling) (...)

So there is an effective (very high - depends on length) inductivity - and as long as the energy you pulse in is higher than the energy which drains out - there will be a stepchargin effect.

-> that was bullshit from my side....
Thats a weired setup -
If you assume that the coupling between the 2 coils
isn´t perfect - that´s still a method of having
high resistance and less inductivity.
In this setup - there is no back-emf used. The choke is just limiting the current on turning on - if you would have such 10.000 turn coil - the current would be too low.
By having the coil partly compensated -you have less inductivity (current may rise faster) and lots of resistance.

The problem with that circuits is - that such bifilar coils should be seen as "transmission lines" - the models and understanding of transformers and ideal coils - is only a showstopper on understanding these things.

[HeairBear]

Here is the link for the "Independent Study"...  http://aquapulser.com/docs/independent.pdf

All the pics I  posted are from this document. I hope you find it useful.