Partnered Output Coils - Free Energy

[MileHigh]

TK:

Thanks, I suppose "anything is possible."   I thought that it was supposed to be "sine wave in - sine wave out."

I mentioned a while back that the "sine wave in - sine wave out" is like testing a conventional transformer, but instead the conventional transformer is replaced with a "newfangled bucking transfomer."

With the low-side or high-side MOSFET switching you are back in Joule Thief territory, which is a completely different ball game.

MileHigh

[conradelektro]

 @TinselKoala, @MileHigh: thank you for the advice.

I got the AUIRFZ34N

V(BR)DSS  55V
RDS(on) max.  0.040Ω
ID  29A

seems also to be better suited than the IRF840.

But I think I go directly to my mono audio amplifier, as MileHigh suggests. I do not think that it will show something special, but one should try it any way.

http://www.conrad.at/ce/de/product/117560/Kemo-Verstaerker-Modul-M032N-Baustein-6-16-VDC-Ausgangsleistung-12-W

The question is how to connect the function generator to the input of the audio amplifier. The description suggests a 10 K potentiometer.


Attached please see a circuit diagram for the connection of the audio amplifier (function generator, primary).

I will check my function generator, the oscilloscope and the laboratory power supply for ground connections.

Greetings, Conrad[/font]

[MileHigh]

Conrad:

Thank you for doing a replication To discuss your posting #472.

I don't get your usage of the 100-ohm resistor on the function generator side. Shouldn't it just be one ohm or even 1/2 ohm?  In other words just a current sensing/viewing resistor?  The power input to the circuit is the RMS voltage across the 60-turn coil times the RMS current as measured with the voltage across the current sensing resistor.

I am making an assumption that at low frequencies the current and voltage will be in phase.  Also, to be a bit more precise, with your existing probe placement, the AC voltage across the 60-turn coil will be the AC voltage measured with channel 2 minus the AC voltage measured with channel 1.  Again, I am assuming a one-ohm or 1/2 ohm current sensing resistor, not a 100-ohm resistor.

You should put component designations on your schematic (R1, R2, L1, L2, etc) to make life easier when discussing your circuit.

Your transformer itself looks great.  Note as a (hopefully) interesting exercise, you can take your analysis one step further because you measured all of the coil resistances.  So you can measure your power dissipation in the coils themselves.  I am "keeping it simple" here and assuming a sine wave excitation waveform from your function generator.   In theory there is nothing to be gained by using a nasty square wave excitation waveform.

MileHigh

[MileHigh]

TK:

This is true, but with careful Gate drive voltage settings you can keep the mosfet in its linear response region so it will do a sine wave output when driven with a sine wave input. This will heat the mosfet more than a square wave will, but it does work.

Yes thank you for reminding me about that.  Of course that would be kind of tricky to do and it is "dumb" with no negative feedback.  I believe a big fat MOSFET car audio amplifier is essentially the same thing but it includes the magic of the negative feedback.  So all of the "MOSFET linear region balancing" is hidden inside a black box and you don't have to worry about it.  The differential pair output from the audio amplifier can be a current sourcing and sinking beast that will hold the voltage to whatever the input says the voltage should be.  At least that's my understanding of it.

Also, to be "truer to the spirit of working on the bench" I seem to recall that you posted some nice schematics where a standard op-amp drives a complimentary pair of power transistors to give you a high-current op-amp.  But heck if a $100 car audio amplifier gives you a MOSFET-based 150-watt power servo amplifier (wild guess) that's pretty tempting.

And I will have no stupid snarky comments from Synchro1 please.

MileHigh

[TinselKoala]

The difference between "bucking" and "aiding" series connections of the partnered coils is just the reversal of the hookup of one of the coils, right?

So you can use the "Secret of DPDT", installing a simple double pole, double throw switch on one of the coils to "flip" its connection to the load and the other coil. The "aiding" configuration will have a higher inductance than the "bucking" configuration.