0.34A 1.7V psu dc
I gave the primary 4 more windings
resonant frequency now around 53 kc/s Q is not very high so wide band, no big changes from the primary windings
395.43Vpp hc coil
429.73Vpp hv coil

I could tune to the LMD mode, lets see how that behaves, voltage should become in phase.
edit: There is no LMD mode, went up to 400kc/s no phase shifting.
Might be due to the low magnetic field coupling, as these are high voltage coils that behave like capacitors

ok...
So... whats next?
well... discharge that current coil. but... I only have 100V for that... better first remove som of those secondary windings of the push pull. see if I can get the freqeuncy up to 60.5 kc/s again, and meanwhile lower that voltage, while also giving the primary even more turns.

0.35A 1.8V dc PSU
F=55.3kc/s
I removed 25 windings from the secondary and added 2 more on the new primary which has now a bit thicker wire (1.5mm diameter)
primary now counts 12 windings (didn't measure inductance yet)
I should remove a lot more windings from the secondary.

0.34A 1.9V
f=59.5kc/s (near the aimed 60.5)
I again removed around 25 windings from the secondary

voltages still high, but frequency starts to get in the right spot

1.48A 9.9V dc PSU
measured on the high voltage coil with the hv probe, other probes removed
2.1kV pp if I go higher, the ozone starts hissing on the secondary.
I wanted to push to 15V but didnt want to risk burning the coating of the windings.

power is still a bit high but reasonable.
Since freqeuncy is nearly there,
I will have to add more windings on the primary, to get the voltage WAY down.
pfff

I still dont really get it.
If the voltage is going so much for the current coil, how can the high voltage coil go?

Anyway,
I should just connect the mosfet, add more primary windings and be carefull with the voltage, and see what happens with that parallel resonance

I removed 5 more wings of the secondary and added 6 to the primary
now the resonant freqeuncy is 63kc/s a bit higher but close enough as the Q isnt very high (although that might be needed with the series parallel resonance )

PSU is now 1.00 A at 13.7V dc very nice.
still this gives 2kV pp on the high voltage coil. its a lot...
this was slightly detuned to the 60.6kc/s

So to be clear the total field voltage of the coil capacitor now is 4kv/s since the coils are 180 degrees out of phase.
The problem is I really need a low voltage where I can switch the mosfet without blowing it up.
Maybe that can be solved with the parallel resonance, which will eat up all that voltage, and produce high currents.

enough for today.
It was a good day for testing

the current coil switched to ground.
this bothers me.

first the voltages are to high, this can be resolved by switching to ground before reaching the highest voltage point.

what will that do to the high voltage coil?
well the push pul transformer  is then grounded
on one side like before, so the voltage should rise on the HV coil. that would be good.
is that true?

but, then I introduce a cold current / radiant event on a strange phase of the sine wave.

I still do not fully understand how to get the parallel resonance going, but I assume it is kicked into resonance by this fast discharge cold current, which charges the coil which inturn charges the capacitor.
and resonance is activated

the quick cold current and charge of the parallel capacitor should be very rapid.

But it needs a high voltage present in the coil capacitor.

once the parallel capacitor is charged, it starts resonating in a series parallel mode.
the voltage transforms into a magnetic current.

this current should be in phase with the high voltage coil.

So when the push pull produces voltage
the parallel resonance produces current (90 degrees phase shifted)

Then there is another problem, the body diode passing the current coil and push pull tranformer to ground.

on one side, it is good, as it keeps the voltage low on the negative voltage swing, and thus protects the mosfet from over voltage.
If I would use a series diode, it should be high enough in voltage to protect the mosfet.
so that would lead to 2 series diodes.
which also pass the fast voltage discharge.
not my favorite solution.
hmm

I can always bypass the body diode with a snubber circuit, to protect it. that would be good.


if the discharge to ground is done on the early rise of the positive voltage, and the parallel resonance is kicked into action, then it should consume the push pull voltage? keeping the voltage low?

and the HV coil is then in its negative cycle.
thus, the field will be discharged,
and this charge is placed elsewhere (the parallel capacitor?)

so again I should look at the field dynamics of discharge, displacement current, and charge movement.

what happens to the HV coil , when the current  coil is grounded.

first ungrounded both ends of the push pull secondary are resonant
psu 5.0V 0,41 A
hv coil is above 800V pp
then grounded.
psu 5.0V 0.06A  way less amps due to detuning
voltage is is dropped down to 536.25 Vpp


so the coil detunes, lets retune

I tuned down to the grounded resonant freqeuncy which dropped to 52.8kc/s
And here the psu delivered 0.47A 5.0V Which is to be expected.
voltage rise is towards 1632Vpp Which is also to be expected.

So grounding disrupts the resonant voltage, but there is still enough voltage present in the field.
Actually, the negative voltage is dropped to more positive , which works together with the positive voltage drop to more negative on the other plate, so we have a decrease of charge in the coil capacitor. good.  lets proceed

The mosfet must discharge at the start of the negative voltage rise of the high voltage coil.
lets dial that in with the phase shift, before the mosfet is destroyed

ok I tuned back to the 60.6kc
and delayed the low duty pulse to the start of the negative cycle.
the HV coil is -50V so the HC coil should even be lower.
A safe value.
Lets connect the mosfet and see what happens.

almost went above the 100V limit of the mosfet but it still works.
I probed both sides of the current coil, which are green and yellow, which (still) have the same resonant voltages.

The HV coil starts to become wobbly after the discharge. but, remarkably the positive voltage maximum
is equal to the negative maximum.

What can also be seen, is the rectified negative cycle of the current coil, which is grounded through the body diode.
this is all as expected.

but, the positive voltage half of the current coil shows me, that my delay is timed, at the wrong and of the HV coil cycle.

I should retune the delay, to the point where the negative voltage starts becoming more negative.

BUT HEY WAIT
I already tuned it like that!
Why has the polarity flipped again?
I suspect I will really need to fix those transistors, to get a stable pulse signal, which doesnt phase reverse

I had big trouble to get it working, ass the pulse seemed to disappear on me.
but I managed to get the shot
and what a shot it is!
The delay is now fine tuned to the right place.
The positive voltage is ringing on the current coil,
while the high voltage coil is rising to become more negative.
Then the discharge occurs. The duty is low, but the resonance is completely gone.
(is the mosfet still turned on?)

But very weird is what happens with the HV coil!.
The amplitude is less, as if the mosfet is on and grounding the push pull (detuning it)

But most odd, is the sudden negative DC offset on the High voltage coil. it is AC coupled, and centered around the negative line.
but suddenly, it has a negative dc offset.

That is weird.
ok. This is a lot of data.

The output coil had a 4ohm load. and was grounded on the hv coil drive side.

The low voltage probes where connected to the negative side, so earth ground was present on the circuit.
lets remove that.

ok now everything floats, except the output coil which has one side grounded. this is how it should be.

yellow is the signal probed at the transistor, so only the pulse with the noise is the mosfet discharge (other pulse/mosfet not used)

now the HV coil shows no dc offset. good. (orange)
The current coil is much lower in voltage  good (green)

hey WAIT AGAIN the phase of the discharge has shifted.
I need to retune, and now it is on the negative side of the current coil. that is wrong. it should be positive .

one more try...
see If I can retune it

I cant seem to tune it to the right point in the phase.
The mosfet does sporadically turn on, so I pushed single shot until I got the right signal.

It might be due to the absense of earth ground. the circuit might need better shielding. as the pulse swings wild after it triggers.

ok...
So than this concludes it for now.

The green current probe, is discharged to neutral, but neutrol is not zero but -20 where it stays, until the HV coil voltage start dropping again.
parallel resonance is not yet observed, but these voltages are so low it would not be visible with the 5uF. Maybe the current probe coild see, but with all the noise going on...

HV coil (orange) is again also noisy, but! the positive side is again much higher in voltage. which is when the mosfet body diode grounds the push pull transformer secondary

it is interesting that the choke coil became resonant.

I wonder if I could do the same for the HV coil to step up the voltage much higher.
and then maybe even not directly im series,

but again using a primary secondary.

so that the push pull gives that 600V but not as a resonant sine. this square wave than would drive the high voltage coil.

just a thought.

another one:
what if I not used the low duty cycle, but instead use the mosfet to pump the voltage levels of the coil capacitor to produce the displacement currents?

Still I need another mosfet for this.
irfp260n is a candidate

yes using the choke as resonant step up for the high voltage coil plate is good.

but I also need a separate transformer for the high current coil.
I can relativly easy take the signal and add another ir2110 to make a second push pull.

the secondary should not be resonant, it should give a high(er) voltage square wave.
which drives the parallel cap coil into resonance.

the secondary square wave would act as the high dv dt source, in combination with the high voltage coil plate. enough to create an external energy movement.

so, only a few turns for the step up push pull of the current coil, so its resonant frequency is much higher, and we can drive it way below, so we get a decent square wave.

while the high voltage coil. push pull transformer is resonant, thus having more turns on the secondary. feeding the choke that steps up the voltage further.
that resonant choke is then a half wave resonant?

resistance is often seen as a current limiter.
but When enough voltage is applied, it radiates energy away. as heat.
heat radiation.

so negative resistance does that absorb radiation?

and with impedance, there is no radiation as the energy is contained in the dielectric or magnetic fields, which by themselves resist change in voltage or current

but... current what current? magnetic current.
but dielectric current DOES relate to radiation.
when the dielectric field changes rapidly a radiant energy is created in of out of the conductor, perpendicular to the conductor.

so is that heat, the same as a displacement current flowing out?

and why is heat radiation Infra red, if so is that a wave? with plus and minus alternating?
or is if a continuous flow. hmmm

I have been bothered by light theory every now. and then. the photon which replaces the longitudinal component.

but not really interested in that right now.

high voltage
or high current
both will give the max power at the same moment in time. at the same phase angle.

but... if I have 2 resonant systems
one high voltage
oyher high current
and I phase shift the current, to get the high voltage and high current in phase,
then it is a 90 degrees phase shift. so what does that do to the power cycles?

the will become opposite, one generates while one consumes, and then they alternate.
and that is for the individual resonant systems

when the push pull starts and mosfet M is turned off, there is not yet parallel resonance in the HC coil.

so voltage is available on the HC coil, but opposite in polarity of the HV coil.

can I change the HV coil voltage polarity by reverse connecting it?

if so, can both HC AND HV coils be positive?
No.

because they are the plates of a capacitor
and HV is series resonant with this coil capacitor.

so by switching M mosfet the HC coil becomes parallel resonant. which has high impedance.
the push pull secondary S then has a high impedance on one side and a low impedance on the other side (parallel and series resonant).

I do not fully understand how this is able to start but once it swings, voltage from the HV coil and current from the HC coil should become in phase.

so the timing (phase) of the M mosfet is crucial.

M should have enough positive voltage. partly from the push pull resonant secondary, and partly from the parallel resonance.

this isn't easy at all

since the voltage of the HV coil won't be 30kV but rather be more im the range of 5kV
I need mosfet M to be fast.

now the voltage range, how high do I need it to be?

how fast and how high.
at least the current rating will be low, simce im general higher current mosfets are slower.

I can start with the irf510. but its voltage will be low. 100V

this mosfet is crucial.
I could place it in between S and HC  that would probably have a bit safer voltage levels

after making an analysis, I've come to the conclusion, I can only discharge the HC coil with the M mosfet when the HV coil is negative.

this also means the high voltage of the coil capacitor is discharged through the HC coil, inducing high currents in the coil, which then in turn induce the parallel resonance with the parallel capacitor that is charged by these currents.

So the high dV/dt from the positive voltage HC dicharge through M to neutral, discharges the high voltage field of the coil capacitor HC HV.

HV cannot supply this current, as the push pull transformer is acting as a choke for this high frequency event.

So this is a pure dielectric displacement current into HC from the charged HV HC coil capacitor.

this dielectric displacement current is longitudinal and super fast with extrema high currents.

while the parallel resonant  HC plus parallel cap currents are slow and transverse.

The mosfet diode opens when the PP transformer becomes negative on the HC side, which gives the HV coil a very high positive voltage, during the parallel resonant high current. (if M is timed correctly)

the HC parallel resonance should I theory only swing at the other side where the M is not connected.

this all needs to be tested.

the pp ttansformer secondary S is series resonant with the HV coil plate. so should be low current high voltage, meaning high inductance low capacity.

giving it high inductive reactance. which is good to block the cold current supply from the tramformer during M HC discharge.

Before testing all of this, I should first get the pulse signal right by fixing the transistor glitches 2sc945...
 gain 185,
0.3Vce sat
1.0Vbe sat
100mA
I can use some help with this.

I want to use the 4 volt as collector voltage,
and make it an emittor follower.

4-0.3= 3.7V through emittor- neutral resistor.
current 100mA + 0.54(base)=100.54mA
gives a resistor of 3.7/0.10054=38 Ohm
hmm seems very low. power is 384 mW
which is way above the 250mW limit.
not good.
Ah this should be so simple.
back to school.
oh wait I am autodidact...

I could use a diode to drop the voltage 0.7V plus 0.3V is 1 V, so from 4 to 3V that is perfect.
or... maybe my phase shift IC can even work at a lower voltage, need to check that.
hc123 is 2 to 6 V Vcc
HCT is 4.5 to 5.5V Vcc
I run on 4.0 V so... hey no transistor needed,
I just drop the voltage to 3.5V  give it a 1k to ground on the output, and maybe a 300 ohm current limiter in series to the tl494 and... done. ha that is a easy solution. no transistors needed

I could protect my M mosfet with a parallel zener diode. but is that fast enough?
the TVS could also do the trick but their voltage threshold is vague.
I also found a fast C3M
https://www.digikey.nl/nl/products/detail/wolfspeed-inc/C3M0280090D/5764683

c3m0280090D  which can handle 900 V
and 22A peak,
with
Turn-On Delay Time 5.3 ns
Rise Time 25 ns
Turn-Off Delay Time 8.5 ns
Fall Time 6.4 ns

I could even set them in series usimg my isolated gate driver, buy that would be overkill.

I just need to get the parallel resonance going, then the high impedance should keep the voltage low enough.
so timing of the M mosfet pulse is essential.

and keeping the start voltage low of the pp transformer.

I rewatched my last video (ground currents)
and came to the conclusion that the discharge happened on the maximum voltage point of the parallel resonant coil.

this might even be wromg since it is a different setup but if correct,
then the current coil will have max voltage at the discharge.

this means the current is 90 degrees away, and I should NOT discharge at the max voltage point of the HV coil but 90 degrees further which is where the voltage is zero.

this makes not much sense.
but still it needs to be considered.
anyway, once the transistors are out, and I can properly tune again, I should be able to get the discharge any where. even on the max power point of the resonant HV sine wave.

One thing is clear
when the HV is max negative, the current coil PP ttanformer side is positive and remains positive for half a period.
so after being positive for 90 degrees, a quarter period, the M. mosfet can switch.

the HV coil then at its zero volt point.
and the HC coil after the discharge should then be at its max voltage point. IF ALL ASSUMPTIONS ARE CORRECT
and most of the time they are not...

what if...
the high displacement current induced by the M mosfet discharge,
needs to be 180 degrees out of phase with the magnetic current of the parallel resonant coil?

I keep struggling with these concepts.
the water vortrx short was very clear.
for power you need the 2 currents present with 180 phase shifted,
meaning one is max positive when the other current is max negative.

so... is that displacement current present on the high voltage coil, that acts as the coil capacitor plate?

hmmm

magnet current (conventional conduction current) flows towards the lowest impedance.
if resistance is low, magnetic current is high.

if the dielectric displacement current is opposite, than does that mean it flows towards the highest impedance?
as the dielectric material in a capacitor is considered an isolator, high resistance?

so if the output coil, needs both currents

then one should be high impedance, so parallel resonant,
while the other is low impedance series resonant.

makes sense
so the HV coil series resonant low impedance, provides the dielectric displacement current.

and the HC parallel resonant high impedance coil provides the magnetic conduction current
(induced by fast discharge by M mosfet)