teslas pancake coil

[Gav]

hi all, ive been playing around with this for awhile now, and have had alot of fun doing it, im hoping others might be of some help in improving what i have and maybe even interest others into making 1 themselves.
its made from very good quality single strand copper wire, the transmitter i used 10 wires and joined them at either end to make 1 thick multi stranded wire, so being bifilar the spiral has 20 single stranded wires in it (2 x 10). the outer coil is single stranded which is wrapped around 40 times (just a guess?) i also wound 2 perminant receivers into the coil,1 i attached to an antenna and ground and the other i just experiment with and or run lights off it, it runs from either 1, 2 or 3 AA batterys, when using 3 AA batterys the coil squeals with the sound of high voltage and the raw power transistor gets fairly hot, when using 3AAs i can also flip over the receiver coil and the lights will still work at around 1/4 brightness.
im using a simple setup, c4429 transistor with a 100ohm resistor and cap between the base and coil. i blew up all my other transistors and the c4429 was all i had left to use
the second coil in the video was just an experiment i done, it only shared the same ground and it turns itself on when i use the large coil.
anyway heres the video, click on the picture to open the video
the receiver has 20 leds and the motor is a 12VD motor run from the primary, im not sure on the motors voltage? the leds are at a blinding brightness and the motor is running at its full speed using 2AA's

[Gav]

also, ive used nails to space the coil and there are a few things that need to be fixed, when im finnished experimenting with it i will remake it with timber dowls and make it look nice so i can hang it on my wall

[Ernst]

Nice coil. I too would like that one that Tesla had. You have probably seen the picture with Tesla sitting in front of it reading a book.

I saw Eric Dollard in a video explaining how he made his pancake coil with coax cable (using the outside, shield of the wire). I thought that was a really good idea.
You talk about "perminant receivers", can you explain a bit on what they are, how they are build, etc?

Ernst.

[barbosi]

also, ive used nails to space the coil and there are a few things that need to be fixed, when im finnished experimenting with it i will remake it with timber dowls and make it look nice so i can hang it on my wall

When you finish experimenting, take out the nails, DO NOT put any dowels, as Tesla wanted the spires to TOUCH (if possible) its neighbouring spires. The intent was to minimise the selfinductance by creating/increasing the {parasitic} capacitance of the coil. Read the patent and look at the drawing. The increase of the energy stored as described in the patent is based on that capacitance. Increase the distance between the spires and the magic goes bye-bye.

These are big coils. As reference, the same patent is giving you the rough amount of the spires used. And used with hight voltage. If you want the juice as described in the patent.

: :

[Gav]

yes i have seen the picture of Tesla sitting in front of it reading a book, i think that coil was distroyed by fire and he made another that was slightly smaller and not as neat, maybe he used recycled wire? when i hang my coil i would like to have that photo on the wall with it
the perminant receivers i spoke of, i used 2 extra wires, they are multi stranded wires from an extention cord which were wound with the rest of the wires in the coil, when turned on they both give around 6dcv each, 1 is attached to an antenna/cap and ground.
as i said its only an experiment at the moment so i also have 2 primarys, a multi strand (10 wires joined at the ends to make 1) which is the length of the secondary. and the single strand primary which has around 40 turns. the multi strand primary does not work as well as the single stranded primary.
if i attach the free perminant receiver to the multi strand primary with a diode and cap to make a tank circuit it increases the capacitance and works alot better
1 thing ive worked out is that capacitance is the key to making this work well, i made a lead plate capacitor and replaced it with the cap from the base and it also improved its performance alot, i took the lead plates from an old battery and used a small peice of stainless steal, placed them in an icecream container and filled with water.
its been a while since ive looked at the patients so ill have to have another look
also ill make another video to show the perminant receivers i spoke of and how they work

Gav

[Michelinho]

Hi Gav,

The big coil you see in the picture was probably used to test in the lab the transceiver he was making to show ship to ship communication for the military, I don't think it was a bifilar coil because of the spacing between each spire. It's the only possibility beside being a bifilar coil.

Take care,

Michel