My crazy project

[Rigel4]

Thanks, this is very helpful. I appreciate the info on the 1.5+ Hhz.
With all the things I learn on this forum, this is the best type of info.
I swear I will never through any house device away again (with out harvesting parts).
//wife does not understand this, not alt all.

[Cap-Z-ro]

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...

[tinman]

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.

[picowatt]

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 

   

[tinman]

Tinman,

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



PW 

   

What do you see when a scope probe (10X) is touched to the laminations?
--> I see chaos-will post screen shot today.