Lenzless resonant transformer

[MileHigh]

I think it is important to reiterate one thing about a typical resonance setup, something that is going on in this thread.

Take a look at a secondary that is connected to capacitor as a load.  That can be driven into resonance by a signal applied to the primary.  Naturally you can put a light bulb in series to eyeball the AC current if you want to.

So the secondary circuit looks like a series resonant LC tank with an AC EMF source:   [AC EMF source] -> [Coil + wire resistance] -> [Capacitor]

So when driven at resonance the (Coil + Capacitor) becomes a short circuit and you are left with [AC EMF source] -> [Wire resistance]

That is an AC energy DESTROYER.  At resonance, it will burn off the maximum possible power in the resistance of the winding of the coil.

It seems to me that often people are "chasing after resonance" without realizing that sometimes resonance is a bad thing if you are trying to achieve over unity.

MileHigh

[itsu]

  To estimate their values I'd need to know if CH3 of the Tek scope can be set to 50Ω impedance.

Programming of the SG and Scope later...

verpies, it does have the posibility to set each channel in 50 Ohm impedance.

Thanks,  Itsu

[Jack Noskills]

Ok i followed Jack's directions and paralleled the both secondaries with only one (double) cap (1100nF).
Without bulb it resonates at 10.5KHz (signal injected through L3)

After hooking up the bulb in the secondaries LC, its resonance frequency raised to 18KHz.

Then searching the L3 for resonance (injecting a signal through the both paralleled secondaries without cap/bulb) which was 1MHz.
Bringing down this frequency to 18KHz by using 70nF capacitance (where have i seen that value before).

Now both L3 and the paralleled secondaries with cap (1100nF) and bulb resonate at 18KHz.

In this situation,

Input voltage and current (from FG) are in phase
Minimum input current (is this what you mean by blocking the current?)
maximum input voltage
Maximum input power  (144mW) from FG
maximum output power (122mW bulb max. lit   see picture*)

* as i forgot to measure in the video the voltage/current (power) across/through the output bulb, the picture shows the
blue trace the voltage across the bulb and the green trace the current through the bulb with the red math function blue * green = avg power
(times 2 for the currentprobe terminator)

Video here:  https://www.youtube.com/watch?v=BE7tAbYRg7w&feature=youtu.be

Regards Itsu

Yes, by blocking I meant minimum input current.


Can you verify that input is not affected if you disconnect the output ?
Now can you test the same setup using the other signal gen that gives 30 volt signal ? The one on the vid used 5 volts, right ? At least this is seen on the scope.


If there would have been bulb in the L3 coil to 'measure' input then that bulb would have been more lit than the output bulb ? If so, then there is still some difference compared to my setup.


From this test I now I remember what happened when I first tested this. I had 1000 nf cap in the output and I was about to quit testing, 'just one more sweep and then I dump these cores in the ocean' and as sweep was about to end at 19 kHz my output bulb started to light up. Not very bright though, so I added second 1000 nF cap and then I got better result as frequency dropped to 11 kHz. I could not add more because then my L3 started to leak as the frequency went down and not very easy to find resonance in L3 using caps for me.


So now I am thinking that one way to increase output power is to add more caps in the output side and at the same time keep L3 in the resonance as you already did. The second way could be to increase input voltage, I am not sure but now you can test this easily with your current 18 kHz setup.


If these two options give positive results then next step is to see how increasing the resonant F by spreading turns, using less turns, using thicker wire etc. affects this. Then bring it down by adding more caps in the output. But lets not think about this at the moment, better to keep variables as few as possible for now.

[Jack Noskills]

Itsu:

Jack:

I don't know what you mean by "local inductance field."  More importantly, there is essentially no "influence of a wire to a neighboring wire."  That sounds like an old wives' tale.  In the context of winding wires around a toroid to make an inductor, it's the permeability of the core, and the number of turns that really count.  Also, the core can only store so much magnetic energy before it saturates.  There is a culture of experimenters neglecting or being afraid to correct each other on the forums.  That leads to stagnation, people don't learn because nobody corrects them and it becomes a vicious circle.

MileHigh

I need to correct myself here. What I call local inductance field is actually the magnetic loop of a solenoid through air from end of solenoid to beginning, verpies made me realize that. Anyway, end result is the same: not much influence compared to looped core.


There is magnetic field around a wire so it will affect neighboring wire, but effect is barely noticeable below 20 kHz.

[itsu]

Itsu:

In your latest clip where you have L1 and L2 in parallel and a single capacitor, you still have a very high resonant frequency, implying that L1 and L2 are in a "flux fight" and canceling each other out.  So if you cross one set of wires then L1 and L2 should add together and you should go back to a low resonant frequency.

MileHigh, 

i did cross one set of wires when i started, and found almost no resonance point, untill i cranked up the sensitivity of the scope.
Its like you said, the resonance then is around 175Hz (low again), but very small in amplitude (50mV while inputting 20V pp from the FG).
My thoughts where that they where wrongly connected and now had a "flux fight".

I then changed them to where they are now and found a nice big resonance point around 10.5KHz of about 13V pp which lateron changed to 18KHz when connecting the bulb in series.

So what is the correct connection of the both parelleled coils? Like it is now High Amplitude / high frequency resonance point or low amplitude / low frequency resoance point?


Regards Itsu