The circuit produces an impulse, on one end of the bifilar coil. The impulse is from a back emf (L1), and is injected into the series resonant L2 coil.
So the impulse enters on end of the coil presenting a sudden negative voltage, while the other end of the coil is maximum positive voltage from resonance, giving a huge sudden change in voltage over the coil, creating longitudinal pressure.
This series resonance produces very high currents and voltages, from the positive power supply AND from the impulse. (the resonant coil is powered from BOTH ends)
I feel this powering from both ends, needs to be tuned, so the impulse is balanced with the positive power supply, giving a maximum longitudinal impulse. Just resonance, and just a impulse isn't enough. It needs to be at the right frequency. Probably related to the copper mass of the coil.
When this is tuned properly, the dielectric longitudinal impulse pressure wave is maximal, and is able to elevate a aluminum foil above the coil.
If not properly tuned, the foil will not float, but will be heated up by the eddy currents of the changing high currents/magnetic field.
So the Idea is, to keep tuning the coil, until the effect is observed.
input current and voltage can be measured, to give input power,
The impulse voltage needs to be at the same voltage for each test. If the frequency goes up, more voltage is needed to produce the same back emf voltage and vice versa, lower frequencies need lower voltages.
The coil will need to be the same each time. once we find the right frequency, where the aluminium foil floats,
We can do the test all over again, with a different coil, that has the same mass, but has a bigger center hole, that changes the capacitance/inductance of the coil, so we can see if it plays a role in tuning. (or not).
then if the mass really is the key, we test again, with a different mass of copper coil. If the realtion ship is found, this would make life easier in the future. But thats to soon...
First make a test setup, with enough load on L2, to keep the voltages down, and choose an impulse voltage.