The LED brightening reminds me of Tinselkoala's power transmitter hoops putting the automotive bulb into 'Supernova Mode (SNM)' https://www.youtube.com/watch?v=y6qKISIE0Og . Something like that happening here too?

Cool project

(edited to fix link)

The laminations _reduce_ but do not eliminate the eddy currents induced in the cores. When the coils are oscillating you will have voltage in the laminations. I presume you are using an ohmmeter or continuity checker to confirm "complete isolation". But this will not detect capacitive coupling at high frequencies. But without a circuit diagram ... how can we analyze a circuit?

Yep, I suspect capacitive coupling. You could try this experiment: instead of connecting to the core, use a very small capacitor, a few tens or hundreds of pF, connected to the coil itself, and then connect the LED/Coil combo to this capacitor instead of to the core. Sweep frequency. Are you able to light the LED this way?
 
The LED/Inductor combo reminds me of some effects I demonstrated during the Little Miss Mosfet era. I have so many videos of those things that it might take me a while to find it, though.

Hi Brad,

interesting stuff as always!

If you disconnect the scope probe on the pickup coil and led, does the led light stay just as bright?
Keep in mind your scope probe most lightly have a common ground and that could complete circuits.
EDIT
no need to reply to my post. I just looked at your video again and it looks like you are using the scope ground to carry ground to your pickup coil and led and you are quite aware of the coupling.

Maybe put a shunt resistor on your signal generator input and hook up your scope to it to see if the current changes when you connect the led?   obviously you would connect a separate wire going to your coil and led and not use the scope ground.

No,i dont think that is the same. Looks to me like a single turn coil/light bulb combo,being powered by magnetic induction-wireless transmition. When TK gets the supernova thing happening,i believe that is just the transmiting and recieving coils coming into resonance.

That's right. When the Rx and Tx loops are close in my system, the resonant frequency of both parts shifts slightly to come closer into precise tuning. I don't think your system is doing this.

Tinman, it may be of interest to see if the LED would light if you had put the other stator into physical contact with the outside edge of the coiled stator, and placed the probe on the opposite side of the contact point...and whether the brightness or the AC draw would change every time you relocated the probe.

Regards...

Well here is a bit of interesting information Cap. I measured the avaliable power between the stator core and ground. 123uA @ .13 volts AC. This i think would be the eddy current power?. Now,the only thing we do is place an inductor between ground and the core,and an LED(either way around) across that inductor. As you can see in the video,there is no way 123uA @ .13 volts would drive that LED to the point of blowing. There is also the fact that we now have a current of around 5mA,and a voltage across that LED of around 3.8 volts. It almost looks as though it is a tank circuit that puts out far more than it consume's-->no reflection on P/in shown either,by DMM and scope . But i have learned not to let these things fool me so easly these day's,and FAR more reserch and experimenting is needed. Like i said in the video-probably nothing to it,but until i know whats going on,i'll keep looking.

Tinman,

I see that you do indeed live in the land "down under".  Apparently, even ground symbols on schematics point upwards!

Having taken a quick look at your videos, I think what you are seeing is related to capacitive coupling and your receiving coil's self resonant frequency (SRF).

Your waveforms have fairly fast rise times, meaning that there is a great deal of high frequency content.  Although your square wave's repetition rate is <20K, you have significant harmonics at 5 to 10 times that frequency.  Your scope likely has spectrum/FFT display capabilities which would help you better visualize the frequencies you are actually dealing with. 

You might also explore this using low level sine waves from your gen, sweeping up into the 100 to 300K range to investigate the stator's SRF (and your receiving coil as well).  That is such a cool looking gen however, I would consider placing some back to back zeners across the input just in case the voltage climbed excessively at the stator's SRF (if you have a schematic for your gen, you could look to see if there are protection diodes from the gen output to the rails prior to the 50R output resistor, always nice to know if they are there).  Adding additional resistance between the gen out and stator will also help protect the gen a bit till you get to know the stator response.  Not knowing how robust/repairable that gen's output circuit is, I don't want to suggest anything that might harm it!   

As for eddy currents, they mostly circulate within each steel lamination sheet and due to the steel's relatively low resistance, are usually very low voltage.  At high frequencies, some skin effect may develop, but I believe the bulk of what you are seeing is related to capacitive coupling and dielectric properties at the higher frequencies you are using. 

I deal with high quality dielectrics every day that I wish were indeed true insulators under the conditions I need to use them.  Around here, 100 picoamps of current flow is considered a short circuit! 

What do you see when a scope probe (10X) is touched to the laminations?

PW