HC1
ok first I checked if the phase is right and it is.
just 0.76A and 0.9V on the HV psu.
13.2V 0.01A on the HC coil
all probes the same.
note how the current already is boosted by the voltage/displacement current (only 590vpp)

hc2
No voltage on the HV psu, just the same voltage on the HC psu
13.2V 0.01A
note how different the current curve looks (choke is no longer on the right, it is now in the center tap)

hc3
0.01A 13.2V hc
3.49A 4.7V hv
Note how now the current is amplified by the voltage, without increasing the HC psu.
green current is larger, but somehow,
 it looks like the change in voltage is reducing the magnetic  current at the switching point (green).

I am going to remove the load. (never lit up, currents are to low)
I will keep the load coil grounded



also I will soon remove the load. to let it run free. now the 20W bulb is still on

noload1
2.77A 3.5V hv psu
0 0 hc psu
no load, output coil is opened up, but still grounded
more current 2.6A pp hc coil
with 2kv pp on the hv coil

noload2
0.13A 20.7V hc psu
2.74A 3.5V HV psu
current is slightly shifted to the left, while diminishing if I increase the hc voltage psu
Then it is amplified 3.14App
yellow still 2.1kv pp

ornage dip in voltage (drain) is also shifting, if I increase the hc psu voltage.
weird.

I need to retune for max current. so it wont phase shift

aha
I tuned the HC coil to 15.67kc/s resonant. So The HV coil somehow has a lower resonant freqeuncy.
I could add more capacity to the HC coil to get it to the right freqeuncy

this was with 0.01A and 13.7V on the HC psu,
HV psu 0 0

YES!!!
now the current is hugely amplified when I increase voltage on the HV psu.

Resonant frequency of the HC coil is 15.6kc/s (5.4uF in parallel)

0.03A 13.8V hc psu (same)
1.8A 5.9V hv psu

Notice I now need less power for the hv coil. partly this is because the hv coil is now detuned above the resonant freqeuncy
but also, the high currents should reduce the current. If I remove that 13.8V it should be clear.

9.74 A pp that is what I wanted to see! current is hugely amplified.
if I would load this down it should show some light as the 12V 20W lamp only needs 1.67A (dc)

Also note, the phase is again off. I switch to early before voltage comes to zero (due to detuning)
but the amps almost become in phase.

SO it is really all about TUNING correctly.

also notice how the voltage rises in orange at the drain. when the mosfet is turned off (blue gate low)

While tuning the HV coil I noticed I can get both voltage and current in phase.
very cool to see,
this was with only the hv psu on 1.71A 4.8V
hc psu 0 0

a lot of amps. with just one psu, the hv...

I just need to give it some juice, and see what happens if I connect the lamp
I dont expect anything

nope if I increase voltage of the HC coil, the phase shifts again

HV coil is resonant at 14.6994 kc/s
So I definetly need to add capacity to the HC coil.

BUT my HV coil sits on my desk, so the high voltage is coupled to the wood which is a good dielectric.
If I lift it above the desk, the capacity could decrease enough to raise the freqeuncy just a little but.
Also a chance of less ozone at higher voltages. (I even think I might need to increase a layer around the coil to get even less ozone

3.69A 5.0V hv psu only,
gives 4.44 kV pp
and 3.7632 A (detuned)

I removed the grounded output coil wire away from the HV coil,

And rewound the HV end wire on the probe, more away from the metal under the tape.
now I can easily reach high voltages. the 4.44kV is actually much higher might be 15kV pp but that is a guess

current will be much higher, when properly tuned

Inductance (L) = 19.268342487 µH calculated from
Resonant Frequency,  15.584 KHz
and capacity 5.413 uF

I need 14.699 kc/s
so for the same inductance that is 6.085 uF
So I need to add 672nF

I added 6x 100nf and now it measures
6.037uF
that is very close to where it should be,

this is with only the HV psu turned on.
Voltage is maximum when current is in phase?
Voltage coil is now tuned to 14.8986kc/s

this is with only the HC PSU turned on 13.9V 0.01A 139mA power
resonant at 14.9161 kc/s
in other words, YES they are now perfectly in tune.
1.6A pp

now lets turn them both on

the currents shifts slightly to the left, is is diminished during this, while I turn up the voltage of the hc coil.
then when I crank up the voltage higher, the phase shift settles, and the current is amplified.
but then also the spikes return to the system, and I need to keep them low enough for the mosfets

so it is tuned, but the -90 degrees phase shift has vanished.
so should I adjust the delay of the mosfet gate signal?

set the signal more to the right, and see if the current stays in phase

hmm, but it is actually good, that the phase is shifting, as the current should be -90 to to voltage.
hej/ but what do I know?

hc psu
19.6V  0.13A
2.1V 1.64V hv psu

I increased power gradually to the HC coil up to
0.4A 23.3V 9.36W
while having the hv coil constant at
3.81A 5.1V 19.4W
producing 4.87kV pp (loose probed, so more like 15kV pp)

again it starts out in phase with current and voltage
then the current drops in magnitude,
and starts shifting left to the -90 degrees position (where it should be)
once it is past the minimum value, and closing in to the -90 degrees position
the current start rising again.

the spikes were not there, since I tuned better to the zero volt point

current now is not so clearly amplified due to the phase shifts.
But If I would push high in voltage on hte current coil psu the shift would probably make it to full -90 degrees, resulting in a massive amplification of current, due to being in phase with the large displacement currents of the 15kV

so...
should I then tune again, so that both the voltage and current are maximum and at -90 degrees?
just reduce the capacity a little bit again, and see if that is posible?

Why are they dancing this phase shift dance?
why is there again a dip on the orange drain voltage?
amps are high, but should be much much higher by now.
hmm

so, one resonant system by itself, tunes to the right same resonant freqeuncy.

but once both are powered, they start detuning (good)

if only the voltage coil is powered, then magnetic current and voltage are in phase. (not good)

why is this?
is somehow the capacity inductance, reactance or impedance changed?

clearly they want to be tuned to the same frequency, when separate powered.

why is that voltage and current in phase? when only the HV coil is powered? it that due to the choke connection in hte middle of the bifi coil? that should not matter, as there is no current flow.

detuning....
ok then I should tune while both are powered, look for the maximums, and if they deviate, then again adjust capacity.

let me sit on this...

15.5V 0.01A hcpsu no hv psu
Why is the current phase shifted like that VS the gate of the mosfet
this is weird.
Must be due to the choke connected to the middel and not the other end of the coil lets do that again.\

nope, I checked just. it is not the choke at one end.
somehow the maximum is reached and phase shifting. Maybe because the coil is capacitive coupled???

Ill put the choke back to the middle

detuning then I can fix it, but no proper current amplification as before.
so lets return
remove the capacity and get it amplified again

weird.
current is amplified, didnt remove caps
I only first tuned to the current maximum with onlt the hc psu.
then I added hv psu and it is then amplified
no phase shifting.
So the current coil sets the frequency, and the voltage coil is shifted. ok

but when I played with the phase shift of the mosfet, nothing really changed!

I think key really is that both coil are tuned to their maximum current and voltages (so both resonant at the same frequency)
while having a -90 phase shift.
So the tuning cant be done independently. both must be powered. and maximum at -90 degrees.

this is where intuition will help. tune, remove capacity, tune again, etc...
until both are maximum at the same frequency while -90 degrees phase shifted.

it starts making sense
now it is perfectly tuned, voltage and current in phase. not good.
I need to detune, because that is when the phase shift happens.

I can simply put the voltage coil in tune, and look at the phase angle of the current coil.
which I already almost had at -90degrees.
So now I will again decrees the parallel capacity, until the  the current is at -90 degrees relative to the voltage, when tuned to the maximum voltage.

then, when perfectly tuned, I can tune into the maximum current resonance, and then the voltage will automaticly phase shift into the right position.

lets see if this works.

so this is how it is now, with all the added capacity (6x100nf plus 5,4uF)
the voltage maximum is very wide in band width. but it is perfectly centered around 14.8581 kc/s
current is in phase.
only HV psu used 1.47A 1.9V

300nF removed. slight phase shift visible.  green current is shifted to the left as expected.
F res shifted to 14.7783
current is decrease but that is ok
I will again remove 300nF

another 300nF removed, total -600nF now. still need less capacity.
I can now also increase psu voltage as current draw is less

-900nF removed, I have now 5x 1uF left in the bank, so I will need to remove 1uf and put in 300 or 600nf
but first I will dial in the current maximum, and look ant the voltage phase

almost -90 degrees, this is 4uF plus 3x100nF
going to remove those 300 also, keep the 4uF

4uF seems spot on. Voltage is resonant at 14.861 kc/s
now lets see what happens with the phase, when I dial into the current maximum, which now must be higher due to the lower capacity