Kapanadze Cousin - DALLY FREE ENERGY

[Void]

Ok, just conducted a new set of tests with the ferrite yoke core-half removed,
so, with just an air core coil to see if the reults I am seeing have anything to do with
the ferrite core or not.

In the first screen shot it is an air core coil with just a strip of aluminum foil run through
the center of the coil for the scope probe to connect to.

In the second screen shot it is an air core coil with just a strip of copper foil run through
the center of the coil for the scope probe to connect to.

These spectrum analyzer traces are made with the PWM set at about 5 kHz and driving the coil with about 2 V
are about the same with the air core coil, with no ferrite yoke core at all. It appears whatever I
am seeing on my spectrum analyzer is not due to the ferrite core at all. Still not sure what is causing it
at this point however. That ~1 MHz peak only appears at certain frequency settings of my PWM driver cct, such as
5, 10, 15, and 20 kHz, and there has to be a certain minimum current flowing through the coil. It would seem
that what I am seeing here may well just be some artifact of my test setup however. Maybe the current limiting
on my bench power supply starts oscillating at around 1 MHz when the PWM is running at those frequencies I mentioned.
At this point, I am suspecting my bench power supply as a possible cause. I will have to try testing with a 1.5 V
battery as the coil pulse voltage and see if the peak around 1 MHz disappears. I have a feeling this peak I was
seeing might be some weirdness with my bench power supply's current limiting circuitry however...

Itsu, it was just about 10 turns or so of insulated copper wire wrapped around the yoke core half, with a strip of aluminum
foil between the yoke core half and the winding, used to connect the scope probe tip to, for picking up the resulting
frequency spectrum.

[Void]

Ok, tested by using a 1.5 V battery as the voltage source for pulsing the coil, and I still
get that peak around 1 MHz, but only when the PWM driver is set to frequencies on
multiples of about 5 kHz.   That big peak is completely gone when running the PWM driver at
frequencies in between those frequencies. The most likely thing remaining I can think of as being
a cause of this is that it is switching noise coming from the PWM driver circuitry, but for some strange
reason this only occurs when the PWM driver is set to the specific frequencies I mentioned.

I have a couple of UF4007 diodes in reverse from the coil V+ to the drain to limit the switching spike
from the coil, and when I disconnected them the frequency of the peak shifted down a bit in frequency, 
but the peak is still there. I guess what I have been seeing is some sort of weird switching noise from
the PWM circuitry or driver FET, but it is very odd that this peak only appears at certain driving frequencies
of the PWM. The fact that it shifted down in frequency a bit when I disconnected the UF4007 diodes seems
to indicate that it is some kind of switching noise related to the PWM circuitry.  I'll just put it down to some
weird PWM switching noise for now...

[verpies]

I did some tests with 2x 12V/21W bulbs in series on the 24V PS as a load and i think that D1 an T1000 are correct, i get the same cycling, so its the difference between the 24V battery voltage and the 24V PS voltage which battle it out.

Minus the forward voltage drops of the PS diodes.

The 14Mhz signal was traced to the both MOSFETs, so probably, as was mentioned by Verpies, its the MOSFETs ringing

Yes, but I doubt the MOSFETs are ringing with the inductance of the primary winding, because this inductance is simply too large to yield such high frequency. 
Pls use the formula C = 1/(39.478 * f² * L) to calculate how low of a capacitance you'd need to have, in order to get a 14MHz LC resonance frequency (f) with your primary inductance (L).

Also, a time-domain scopeshot of the drain waveform would be useful to identify the ringing stage.

or a LC parasitic.

Pls try to connect a parallel 47pF cap to the gate and/or drain of the MOSFET in order to locate where that LC parasitic is exactly.  Look for downward frequency shift.

I notice that both MOSFETs show a different frequency peak (14.08MHz versus 13.75MHz), so i guess it could be the ringing from the primaries LC frequency, which could slightly differ from each other.

It could be related to the placement of the air gap under the windings or the capacitance of the winding but doubtfully related to the inductance of the primary winding which is simply too large to resonate at this frequency with realistic capacitances.

Waving with a stack of 4 ceramic magnets has no influence on these peaks (or not noticeable) but i do see and hear a sudden change when approaching the yoke, it starts to squeal and we see several peaks coming up all over the spectrum,

First of all, these additional peaks cannot be related to the yoke just changing its inductance, because such change would only cause a frequency shift of the existing peak.

New peaks cannot appear due to a change of inductance, but they can appear due to any nonlinearities introduced, such as ferrimagnetic saturation^* ...and other effects.

which is probably what I call the chaotic mode...

It is not so chaotic:

First of all, the peaks at 18.833MHz, 28.250MHz, 37.6666MHz, 47.08333MHz are all consecutive harmonics of the 9.416MHz peak.
That leaves only the small peak at 35.25MHz as the odd one.

The 14MHz is also unrelated to any other peaks, but notice, that this 14MHz peak does not belong to the group of peaks that was caused by the permanent magnets.


^{* It is unlikely, that these relatively small and weak ceramic magnets could saturate such a large yoke core.}

[Jeg]

For a brief moment when the internal caps in the power supply are charged and all the internal voltage thresholds are met, the power supply likely does provide the driving power to your system. 

When the power supply activates, it has the full regulated 24 volts and since this 24 volts exceeds the 22.5 volts of the battery, it takes over. 

Exactly! Just to add on your explanation that the diode acts as a switch. If for example a diode is connected at the output of the battery, it conducts when its cathode is at lower potential level than its anode. If for some reason cathode is at higher potential like when the psu outputting higher voltage for a brief moment, then diode stops conducting, and for that moment psu is the main and only dc supply provider.

"Itsu said:..makes no sense to me as the battery is always connected to the system, so why would it "stop powering the system" in the first place?"

Does it have any sense now?

[verpies]

Ok, tested by using a 1.5 V battery as the voltage source for pulsing the coil, and I still
get that peak around 1 MHz, but only when the PWM driver is set to frequencies on
multiples of about 5 kHz.   That big peak is completely gone when running the PWM driver at
frequencies in between those frequencies. The most likely thing remaining I can think of as being
a cause of this is that it is switching noise coming from the PWM driver circuitry, but for some strange
reason this only occurs when the PWM driver is set to the specific frequencies I mentioned.

That is strange considering the 200x ratio between 5kHz and 1MHz.
I'd look into the scope's sampling frequency relationship.

I have a couple of UF4007 diodes in reverse from the coil V+ to the drain to limit the switching spike
from the coil, and when I disconnected them the frequency of the peak shifted down a bit in frequency, 
but the peak is still there.

That is strange, too.

The fact that it shifted down in frequency a bit when I disconnected the UF4007 diodes seems
to indicate that it is some kind of switching noise related to the PWM circuitry. 

These diodes have a reverse capacitance. Eliminating parallel capacitance would shift up the frequency...unless it was series capacitance.  But where?
What happens when you put a 100pF cap in place of these diodes?