TinselKoala's Magnetics Workbench

[TinselKoala]

In the video I described, and showed, 2 spark strengths. By "intermediate" I mean a spark strength that was, well, intermediate between the other two strengths shown.
I have so far only pulsed the coils with the damped oscillatory AC high-voltage ringdown capacitive discharge produced by my little 6 kV power supply, 110 nF doorknob cap stack, and high-speed rotary spark gap.
So far, as far as magnetic field strength goes, I have noticed no differences in behaviour of the two types of coil. But it does seem as though the TBC stores and returns more energy overall, probably due to the electric field rather than the magnetic.
But I still haven't had a chance to complete the gimballed magnet for direction mapping.

[0c]

So the TBC makes a better transmitter and the spiral pancake coil is a better receiver?

I'm anxious to see the results of the DC magnetic field intensity and field shape experiments. To see if there is any truth to the rumor that the TBC has a stronger field. This should be tested with steady low-voltage DC and with short (0.1 to 0.05 second) DC pulses to check for differences between the two coil types.

I've also heard rumors the Lenz effects are minimal or nonexistent in a TBC, thus my earlier comment about possibly setting up a pendulum to swing over the coil. Of course, being the wacko I am, the pendulum arm and bob may not be quite as straightforward as one might think. I do have some deviant thoughts. 

0c

[TinselKoala]

Hmmm--I think there are many confusions around the terminology and the construction. Who knows just exactly what is being reported, and with what kind of how-wound coil? I would think that the fact that inductive pickup can be demonstrated in the TBC, would also imply that LL holds true as well. But perhaps not.
I now have a suitable driver/amplifier for the coil magnetic field testing, thanks to groundloop and gotoluc.
Why don't you see if you can come up with some specific parameters for your pendulum experiment, that will be able to compare the TBC with the pancake. The driver circuit is configured to produce a 50 percent duty cycle square pulse, at whatever frequency is reasonable, when clocked from a signal generator. But I can probably figure out a way modify the duty cycle and how to trigger it from a Hall sensor or optical commutation or deconvolved modified pings...whatever those are.

[0c]

I agree, there are many wild and unfounded claims out on the internet. The purpose of some of these tests is to verify or disprove those claims. I'm only focusing on magnetics here. I have seen claims that a TBC:

1) creates a more intense magnetic field than a spiral pancake coil for a given input power. I don't recall whether this applies to DC, pulsed DC, or only AC.

- The first tests with DC or pulsed DC are designed to check the validity of this statement and to see if there are any interesting differences in the magnetic intensity or the shape of the magnetic field.

2) shows very little or no Lenz Law effects.

- A simple pendulum with a magnet at the end in a fixed orientation (N facing down) can be placed so it passes across the coil. The magnet should be smaller than the core diameter. The coil should be shorted or connected through a very small resistance.  If LL holds, the pendulum should hesitate or slow or tend to swing around the core as it approches the center and should meet further resistance after passing the center.

- Flip the coil over so the spiral goes the other direction (CW instead of CCW). Does a coil wound the opposite direction demonstrate any difference in behavior? Magnetic polarity?

- Replace the fixed magnet with a diametrically magnetized cylinder that can spin and change its orientation WRT the coil as it passes over. This is the nonstandard pendulum I mentioned.

- Another variation would be to use a double arm at varying angles between the arms, so they pass over different areas of the coil, in differing magnetic relationships WRT the coil and each other. Both fixed and spinning diametric magnets can be tried.

Note: If a small resistor is used across the coil terminals, the induced voltage can be measured. A Hall sensor can be placed near the core to monitor changes in the magnetic field. A dual trace scope can show the relationships between the two at any moment in time.

0c

[TinselKoala]

Much to do, I see. I think I understand what you are getting at. I would expect one of the other "bifilar" types to behave in a non-LL way, but I think the TBC will respect LL. I'll try to set up the experiment exactly as you describe, only different, as usual.

Meanwhile you may (or may not) be interested in this new video, where I used the TBC as a primary in a Tesla power magnifying system in a replication (partial) of gotoluc's and groundloop's work.
http://www.youtube.com/watch?v=5tW2g4KinuA