Tesla Bifilar Choke

[Login to see usernames]

There's more than one way to wind a bifilar coil.  An example which often comes to mind is Tesla's pancake coil.  He wound a flat coil, with two side by side wires spiraling outwards from the center.  When finished, the inner end of the second wire was brought out and connected to the outer end of the first wire.  Then the outer end of the second wire, together with the inner end of the first wire formed the coil's two leads.

This same system can be applied to a solenoid coil having two layers.  The end of the inner layer is brought back to the starting end, for the beginning of the second layer.  So the starting end of the inner layer, together with the far end of the outer layer comprise the two leads.

(http://s20.postimg.org/whalr0mlp/Tesla_Solenoid_Choke.jpg)

It can be seen that this is equivalent to using speaker wire to wrap Tesla's pancake coil, with the two layers stacked.  Doubling up on the two layer coils can provide a choke, depending on how the twin, two layer solenoid coils are connected to each other.

[Login to see usernames]

yes man this is very nice winding style,.. i remember there is a name for it but i just cant remember the name...

its used to icrease the distributed capacitance allowing more equally distributed voltage in high voltage transformers..

also interlayer can be used... i posted something about it a while ago... in my project page

[Login to see usernames]

in clothing shops they have those plastic tags on for shop lifting security . not long ago I opened one and it has a single flat coil like that and a capacitor soldered on , so maybe it acts as a tank ciruit frequency when it goes through the door monitor ... and no I wasnt shop lifting but interesting to see inside

[Login to see usernames]

yes man this is very nice winding style,.. i remember there is a name for it but i just cant remember the name...

its used to icrease the distributed capacitance allowing more equally distributed voltage in high voltage transformers..

also interlayer can be used... i posted something about it a while ago... in my project page

Yes, this goes back a long way.  Someone taught me the 'skill in the art' part of the loop back, in 1962 - less than 20 years after Tesla's passing.  Tesla may have published it somewhere; if not, many of his non published things are still circulating in the 'underground' community.  The advantage of an interlayer is a big increase in the coil's Q.  But the added capacitance changes the resonance.  The length of each layer's wire needs to be a quarter wavelength, although square wave pulsing allows use of a sub harmonic.

in clothing shops they have those plastic tags on for shop lifting security . not long ago I opened one and it has a single flat coil like that and a capacitor soldered on , so maybe it acts as a tank ciruit frequency when it goes through the door monitor ... and no I wasnt shop lifting but interesting to see inside

I looked inside one of those too, out of curiosity.  It isn't possible to make two of those little tank circuits exactly the same.  Hence, each will look different to the scanner.

[Login to see usernames]

so if the coil wire is 1/4 wave lengh then that could be described as a 1/4 wave , whip antenna , yes?  nien?

[Login to see usernames]

one interesting thing i noticed is that this coils when pulsed in a transformer are made to oscilate stronger at its self resonant frequency and its proportinoal to the oscilation of a half wave string... moment of huge stress than zero stress