Electron Reversing Device

TinselKoala · January 13, 2013, 09:42:04 PM

Quote from: poynt99 on January 13, 2013, 09:14:16 PM
TK,

Did you remove the connection between the two coils to make your capacitance measurement with the meters?

You would then be measuring between two open-ended coils. I assume that is what tinman did.

In post #48, page before this one, I reported:

QuoteWhen I break the center tap and measure the two adjacent windings on the 685 uHy coil without them being connected together I get around 2 nF.
(Incidentally this coil will light an LED, _even with the center tap open_ , when it picks up the EM from another TB coil driven at the right freq range.

TinselKoala · January 13, 2013, 09:50:46 PM

Winding a bifilar pancake coil onto a CD-ROM blank that has been sprayed with 3M Super77 adhesive. The wires are coming off two spools and are gently wound and pressed into the adhesive as I go around, with a wooden popsickle stick.

TinselKoala · January 13, 2013, 10:13:28 PM

Quote from: Magluvin on January 13, 2013, 09:31:23 PM
I had strange effects measuring a spool bifi capacitance. Measuring capacitance between the coils(coils not connected electrically, open ends) like 11nanofarad, but when I connected the cap meter 'across' one coil, as if to measure resistance, it measured near 1uf. Either coil.

I was impressed with this amount of capacitance 'between' the coils. till I realized I was measuring across 1 coil.

Very strange.

Mags

Even stranger for me. If I select high ranges on my cap meters and measure across the total coil, connected at center tap, I can see _negative_ capacitance values on the meter.
There should be a buzzer "wwwoooonkkkk" that goes off when that happens, I think.

Magluvin · January 13, 2013, 10:26:43 PM

Quote from: TinselKoala on January 13, 2013, 10:13:28 PM
Even stranger for me. If I select high ranges on my cap meters and measure across the total coil, connected at center tap, I can see _negative_ capacitance values on the meter.
There should be a buzzer "wwwoooonkkkk" that goes off when that happens, I think.

Lol, they are strange puppies, thats for sure. I tried many things with different coils to try and find some standard to use when determining absolute values and, well, here we are. Many years after its invention, and still no bifi standard calculations. Weird. Maybe Tesla wrote something up on it somewhere.

Mags

Magluvin · January 13, 2013, 10:57:21 PM

When I made my Lil Tc, it has a 2 turn primary. In essence, it is a 2 turn bifi coil. The adjacent windings will have 50v difference if 100v is across. Just an example.

So maybe the 2 turn could be the standard comparison when looking to define the parameters of coils of more turns.

Dunno yet. Just thinkin.

Mags