Self running coil?

[gravityblock]

One shot from the signal generator will re-start the circuit and cause it to self-oscillate again.  This is truly amazing.  A "perfectly" tuned circuit would produce a continuous sine wave and oscillate indefinitely.  I believe this is what I'm seeing.  Please correct me if I'm over-looking something.

GB 

[gotoluc]

Yes gravityblock, you are seeing a circuit that creates its own resonant frequency oscillation

It's not perfect!  but it works. I think this maybe one more step in the right direction.

Now!... we need to better understand how to tune for maximum output with minimum input.

So it still needs lots of work to go OU if possible

Stay tuned for more tuning

Luc

[NextGen67]

Hi Luc,

Interesting effect (but you make way to big steps as far as me concerned haha).

Why, does the circuit self resonance, and why do you need to 'trigger' it once to get going?

Well, see it as a normal L-C circuit, only now the C is made out of the [combination] of Ciss/Coss/Crss(voltage depended) and the small 2nf cap you placed parallel to the coil.

Why do you need to 'trigger' it, to get it going?

Because in initial stage, there is *no* voltage applied to the mosfet, so hence the system can't operate... Once you give it a 'one time shot' with the generator (could be battery also), you start the reaction....

The Bemf from the toroid coil provides the energy to get power the gate again.

Small calculation... your precision meter showed 0.000088 Amp (88uA).

What goes into the mosfet: 10.94 volt RMS (from the coil) which has a 6.9 ohm resistance...

So, 10.94 Volt / 6.9 Ohm = 1.5855 Amp.. Divide this through the Frequency 18120 Hz...  1,5855072463768115942028985507246 / 18120 = 0.0000875 A (87.5uA) which is pretty well what your precision meter shows also.

while your pick-up coil (with 1K resistor) delivers 0.00054A (540ua), the draw it takes from the circuit is only 0.000034A (34uA), that is a nice effect I would say.

It might get *really* interesting if you can get the 0.000088 down to -0.000001 at least

EDIT:  Luc, if you measure the mH of the coil, you would be able to derive the C provided by the mosfet, since you have placed a 2nf in parallel with it... at 18.12Khz and 2nf you are at 38.57mH.

EDIT2: Yes, you can bring down the 0.000088 still, with changing the small 2nf cap, though *how* far down
will you be able to go?  Did you read my info, on how you probably get *best possible* tuning ?
Your circuit is using 0.95mW at this stage [without pick-up coil]. Errr... That would be 1.13mW actually
The total circuit uses 1.13mW, the coil uses 0.95mW, so 1.13-0.95=0.18mW for the operating of the Mosfet (it's switching),
and it's resistance.

EDIT3: Luc, what is the resistance of your pick-up coil? Wonder if it is close to 10.85 or 14.01 Ohm?

--
NextGen67

[NextGen67]

One shot from the signal generator will re-start the circuit and cause it to self-oscillate again.  This is truly amazing.  A "perfectly" tuned circuit would produce a continuous sine wave and oscillate indefinitely.  I believe this is what I'm seeing.  Please correct me if I'm over-looking something.

GB

Still some 0.000088 from that.... Once it get to -0.000001 it is self sustaining (e.g. no battery necessary) and able to give energy back.

--
NextGen67

[Magluvin]

luc  great job at looping the signal.

Well not quite OU but not far off.  1.57mw in  ,  .29mw out

What Im not sure of how the modem transformer is doing it by being across the source and gate. That would indicate that either the source is showing a variation to apply signal to the gate, or the gate is feeding back through the gate against the source and bouncing back to the gate through the modem transformer. Like a small delay.
Not really sure, but it is as I have talked about getting some feedback to run itself. Depending on the gate sig voltage as you have it now, I would try using the pu coil to apply sig to the gate. If that lil modem transformer is not shorted on the one end and instead, connected to the pu coil, phased one way or the other, you may be able to drive the gate higher.

Mags