Lenzless resonant transformer

[Jack Noskills]

Ok,  back to the thread from Jack, i have removed the input bulb, and connected the FG to the L3 making it the primary coil as requested above.

We see no resonance peak in the Primary (L3) other then the V and I phases get lined up at the 65KHz mark which had a 185V peak yesterday.
We see a minor resonance peak of the left bulbless secondary around 85KHz and an even more smaller resonance peak at that same frequency for the
right secondary with bulb.

Severall voltage and current measurements where taken.

Video here: https://www.youtube.com/watch?v=QkdTL7vk_nU&feature=youtu.be

When removing capacitance on the L3 primary coil (till 3.5nF) causing it to resonate around 85KHz (secondary resonance frequency) starts the circus
again of peaking and dipping at resonance as we have seen before on the other coils when trying to match the resonance frequencies (not on video).


All very well explainable behaviour IMHO.


Regards Itsu

How L3 was wound ? It seems as it were wound over empty spot between secondaries. I placed it in the middle of both coils, also at the start of both coils worked. Both seem to give same results. But it should not be placed over both coils in the same half of the toroid, or in the empty spot.


You have M-088 as I do, that's good. You can do exactly same test I did. I think you could start at much lower number of turns and thicker wire as you can go above audio frequencies. Wire does not need to be enamelled. If you put the L3 in the middle of secondaries, then setup matches mine. 30 volt input should be better than 20 volt input.

[itsu]

Thanks MileHigh,  once again, a good explaination, very usefull.

How L3 was wound ? It seems as it were wound over empty spot between secondaries. I placed it in the middle of both coils, also at the start of both coils worked. Both seem to give same results. But it should not be placed over both coils in the same half of the toroid, or in the empty spot.


You have M-088 as I do, that's good. You can do exactly same test I did. I think you could start at much lower number of turns and thicker wire as you can go above audio frequencies. Wire does not need to be enamelled. If you put the L3 in the middle of secondaries, then setup matches mine. 30 volt input should be better than 20 volt input.

Jack, ok,  yes i have the present L3 inbetween the empty spot between secondaries.

Having the nanoperm cores i tried to setup like you mentioned here which states:

I used 1000 nf caps, about 80 turns of 0.31 mm wire and permeability of M88 is 80000.

Will the red L3 as shown in the picture below represent what you mean?
If so, how many turns?  Also 80 like the others?

According to this website: http://www.1728.org/resfreq.htm  the both coils on the nanoperm core should resonate at 184Hz with the given data.
When measuring mines the current in the both coils flatlines (and change phase position) around 140Hz, no real peak though.


Regards itsu

[Jack Noskills]

Thanks MileHigh,  once again, a good explaination, very usefull.


Jack, ok,  yes i have the present L3 inbetween the empty spot between secondaries.

Having the nanoperm cores i tried to setup like you mentioned here which states:

Will the red L3 as shown in the picture below represent what you mean?
If so, how many turns?  Also 80 like the others?

According to this website: http://www.1728.org/resfreq.htm  the both coils on the nanoperm core should resonate at 184Hz with the given data.
When measuring mines the current in the both coils flatlines (and change phase position) around 140Hz, no real peak though.


Regards itsu

I used 90 turns, but I think 1:1 ratio is ok so use 80. Here is a picture of mine, where I used caduceous type winding as a secondary. It gave little bit different results, no need for you to change to caduceous windings though.


Secondary resonance should be around 10-11 kHz in your system.

[verpies]

Here is a picture of mine, where I used caduceous type winding as a secondary.

Oh, so the 3^rd winding is placed as depicted in this diagram of "flux leakage detector".  That makes a big difference.

If you want to minimize capacitive coupling put some spacers between the green winding and red windings (cardboard and several layers of plastic tape is fine).

[itsu]

Ok, just to be complete and to finish the normal ferrite setup, i have removed the L3 coil and set it up as done by Jack and as shown by verpies (90° off from where it was).
Inductance still measures around 1mH.

Then i sweeped this L3 from 800Hz til 100MHz monitoring the input (FG) voltage and current and the voltage from both secondaries.

No real resonance points are seen anymore.
I see a input voltage/current sync (in phase) around 5.6MHz!! at which point also the current swaps from leading to trailing the voltage.
Guess this is the series resonance point of L3 (minimum impedance/ minimum voltage).

After that i see a slight resonance point (2v pp) on mainly the left secondary (without the bulb) around 37MHz!!

Guess that MileHigh is "dead on" with his statement here where it says:

In this case L3 sees "clockwise" flux through the bottom part of the toroid and "counter-clockwise" flux through the top part of the toroid. 
The net flux that L3 sees is zero. 
In the real world we know that there will not be perfect flux cancellation and as a result a very tiny net flux will be picked up by L3.

So in essence L3 is a "nonsense" coil that is illogically placed and does not really contribute to the operation of the magnetic circuit. 
Similarly, when you connect the signal generator to L3 then the toroid sort of acts like a cylindrical core for L3. 
In this case L1 and L2 will barely pick up a signal either, they are stuck in magnetic limbo. 
It's only when you hit a resonance frequency can the feeble signals going into L1 and L2 start to show any amplitude. 
But of course it is a "phantom resonance amplitude" because there is no usable AC power to speak of.

Video here:  https://www.youtube.com/watch?v=usjsc7SZCx4&feature=youtu.be

Regards Itsu