Akula0083 30 Watt Self Running Generator.

[avalon]

The reason you are seeing dying oscillations is discontinuous conduction mode which happens when ripples in inductor current cause polarity switch of applied switch current to reverse.
This could be a result of a poor quality inductor with high parasitic (stray) capacitance (C). When the switch is off the secondary coil still has energy equal to C * U(out)^2/2. Hence - dying oscillations.
There is no free energy here.

~A

... it does not show very clearly the 2 to 3 second dying oscillations that I am seeing after power off ...

[MileHigh]

Farmhand:

This is a statement that might suggest some interesting experiments to you:

In simplified terms:  Let's say, you connect your signal generator to an LC resonator.  The wire resistance is 2 ohms and the peak-to-peak voltage is 10 volts.  There is some measurable power A going into the resonator.

Now say you have the same LC resonator, same inductance and capacitance, but the wire resistance is 1 ohm.  You connect the signal generator and this time the peak-to-peak voltage is 14 volts and there is some measurable power B going into the resonator.

So, the AC voltage increased, but that means more current going through the wire.

Is power A > B or is power B > A or are they roughly the same?

Let's say for the sake of argument that they are the same.  So that means that there are nil returns in terms of power drain reduction when you lower the resistance of the wire in the LC resonator.

Lower resistance equals higher Q factor, and higher voltages and a narrower - 3 dB bandwidth, but not necessarily reduced power burn-off in the resonator.

There are issues of how you couple to the LC resonator and source impedance and source voltage that I did not touch on, but I assume that you get the main point.  The by far far easiest way to do these tests is with pSpice or even that Java simulator.

MileHigh

[Farmhand]

Yes but MileHigh try an LC circuit with 150 Ohms resistance and then to get the same activity in the tank you'll need more input. It all depends on why you are doing it and what you want to achieve. It's all relative I agree.

It also depends on if there is a limiting load or not as well.  If there is no load why do it ?

Cheers

P.S. I'm no expert but I think I see in my setups I can alter the output impedance by tuning.

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[Farmhand]

I want to state at this point something Tesla said in the Colorado Springs Notes, Tesla clearly stated, July 7 1899 page 65 see attachment that a high rate of transformation is better for power transmission, but for signals (small power levels) a great resonant rise can be beneficial.

Now when transmitting power I think the idea is to tune the machine to the load so as to be most efficient, perfect resonance is not the goal, but the device should be capable of being tuned to resonance.

Tesla coiler's know that to get the best performance when making streamers the primary L/C should be tuned to a bit lower frequency than the secondary because when the secondary breaks out in streamers it's resonant frequency drops due to the load. The Spark makers transformer has a load, which is the streamers. They limit the voltage for the input applied but the transformer is still "resonant".

As for resonance in these Akula devices, I don't know, there could be a use for it in some part of some circuit. But to me the circuit seems odd and I see no replications I can believe.

Cheers

[Farmhand]

MileHigh, you are correct though. I know this because I see in my older video's with my small Tesla coil transmitter and receiver setups that when the transmitter is tuned to resonance and the receiver has no load then the input can be higher than when the receiver is lightly loaded. That is because the load is just enough to limit the voltage in the tank to lower the losses. However a tuned setup should be able to be tuned to have a low idle input, then when a load is placed on the receiver the transmitter input goes up, I have also shown that. It is all in the tuning, tuned circuits need to be tuned. And to do that the operator needs to know his circuit to some degree, experimenting with tuned circuits is fun and very educational in a practical way.

The best and simplest tuned circuit is the two Tesla coils with one of them driven by 12 volts and switched at full resonant frequency, with the ability to vary the driving frequency and pulse width and to tune the L/C of the two primaries and the two secondaries. One can learn a lot from such a setup. Using a feedback oscillator can be good but it is different to driving at a frequency that is manually varied. ( a function generator is ok but the power is not enough ) FG good enough to light neon's and see the distribution of potential though.

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P.S. I want to build a "H" bridge circuit to switch a variety of coils, previously I just used DC pulses, switching the primary coil both ways will help for more output I think.

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