Wireless energy transfer experiments ,Builders board

[gotoluc]

Yes you can and yes it  is recommended
By the way,  great  job  .
http://www.hvtesla.com/primary.html
it doesn't  have to be flat  coil

Wesley

Thanks for the reply Wesley

How many turns of 3/8" copper pipe as primary would be needed?

Regards
Luc

[stivep]

what is said   down here  :
don't  take  it to  consideration  yet.
it is  just good to know  it.
#1
Comment under video listed below is  not mine but I like  it very much.
It says about CW /  CCW / bifilar winding method that can be used for e.g HV Tesla coil
to get less winds and  lower frequency of resonance but still   get required  1/4th of wavelength or
1/24 or lower  but still "resonating" as if it was 1/4th. ( quarterwave )
Tariel Kapanadze used  this method  in his coil.

 

Monofilar and bifilar gives the same DC resistance.
What is different is high frequency impedance.
Bifilar gives lower self resonance frequency.
The principle is that there is a certain parasite capacitance between coil windings, which stores a certain amount of energy.
By winding the coil bifilar, you get substantial bigger voltage differences between adjacent windings and therefore more energy
is being stored in these parasite/self capacitances.
Since the energy stored in a capacitor equals 1/2 C V^2 ( Energy Stored on a Capacitor ),
this is a significant difference in the amount of energy that is being stored in the coils self capacitance.
And since in resonance, this energy is being flipped back and forth between the capacitance (voltage) and the inductance (current, magnetic component).
You get significantly stronger oscillations with bifilar coil at resonance frequency.

Tesla Bifilar Coil DC Resistance: Pancake (1)
https://www.youtube.com/watch?v=8fTf9IlPYmY
by TinselKoala.
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#2
https://www.teslacoildesign.com/design.html
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#3
Two coil or double-resonant circuits - Virtually all present Tesla coils use the two coil resonant transformer,
consisting of a primary winding to which current pulses are applied, and a secondary winding that produces the high voltage, invented by Tesla in 1891.
https://en.wikipedia.org/wiki/Tesla_coil
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this is just funny video for your entertainment only: 
https://www.youtube.com/watch?v=5gSXi3BkkNA

Wesley

[poynt99]

Luc,

Allow me to ask this:

- Will your power transmission work without the top load capacitors in place?

- If the top terminal is one plate of a capacitor, where or what is the second plate?

- How do capacitors work?

btw, for the record, I am not an EE (and I don't believe I've ever claimed to be).

[d3x0r]

I was going to be challenging again; but deleted that.


I did run with the dielectric being important....
Vaccuum = 1
air = 1.00000036 or something, basically vaccuum
ptfe/teflon is only at 2.1... (I'll have to strip some wire and see if I really get 2x capacitance with the insulation...)


water though is  (87.9, 80.2, 55.5) @ (0, 20, 100 °C) Edit: ( ya, or vodka)

.  should be able to run a single conductor through water and get a really good dielectric self-capacitance increase.
though they seem to call it Relative permittivity suppose that's why they use water in super caps?

---
Re copper pipe primary - tesla coil builders suggest that it be a proportion of the secondary... though when doing a kacher sort of circuit, anywhere from 1 to  12 windings worked, but the resonant frequency would change.  There is some sweet balance I'm sure between the inductance/magnetic reactance of the primary vs the secondary that will probably exist, but that's starting to be mechanically resonant. (no help, just personal observations)

[stivep]

How many turns of 3/8" copper pipe as primary would be needed?

https://youtu.be/XOTLfnMOSqQ?t=661
look  here   at 2200m
it is 8  turns.
but  gauge AWG 1, 2 or 4 electrical wire is perfectly Ok  too.
Voltage is  determined by turns ratio between primary and secondary  not by  the  gauge.

Here  you  have calculator:
https://www.teslascientific.com/products/coil-inductance-calculator/
keep  in  mind that  Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer
https://wikivisually.com/wiki/Tesla_coil
spark gap to excite oscillations in the tuned transformer. More sophisticated designs use transistor or thyristor^[15]
switches or vacuum tube electronic oscillators to drive the resonant transformer.

So in early Tariel Kapanadze devices  use of spark gap was the  easiest way to  create  wide envelope of  suitable frequencies
(at wide bandwidth)
Depends  from:
- spark gap distance between electrodes 
- voltage  delivered to the spark gap
-material   used to make spark gap
the Frequencies  of very small amplitude  growing up   to  its maximum  and that  falling down  to its minimum 
created  quite  wide  top  resonance frequencies of  few kHz  wide amplitude  only  when:
- given primary winding was tuned  by use  of capacitor or by  puling out/in winds (and by that changing diameter of coil)
So the spark gap by itself made spectrum of frequencies that Have  been  than shaped/ determined/  dependent
from  resonant  frequency of primary  winding.
However  secondary  winding  has its own resonant frequency-ies ,so  function of primary  is to deliver electrical potential  to secondary.
Because you have  ratio of winds  of primary   vs secondary than like in every transformer  voltage  at  secondary will depend
from that  ratio.
e.g  if primary is:
- 1 wind/1V  than at  secondary having 1000  winds    (ratio 1:1000)    ,voltage =  1000V
and if
- 3 winds/1V   than at  secondary having 1000  winds ( ratio 3:1000)  ,voltage =  333.33V
- 8 winds/1V   than at  secondary having 1000  winds ( ratio 8:1000)  ,voltage =  125.V

so someone may ask  why I need all of this?
example:
we have two  coil structure  Rx and Tx.
if your Tx  secondary  winding   of Tesla  coil is in resonance but frequency  it is not much   stable and is drifting  left/ right
than if it is feed by  nice  good stable generator the bandwidth  of  this resonance will be narrow.
So  Rx( another the  same Tesla coil) at some distance  from  Tx must be  sharp  tuned to  this  particular frequency.
But if  Rx frequency drifts  or Tx    frequency drifts than you have no  energy transfer  from  Tx  to Rx.
However if you have spark gap  in Tx than:
-if Tx drifts than due to wide  frequency spectrum  created by  spark  Gap  is at high amplitude close  to  its  maximum center and Tx will 
transmit at just  slightly  lower  power at  closest  adjacent  frequency  to the frequency  it drifted from.
Than at some distance we   have Rx  that  can be  retuned if needed or  just left alone as  the energy   received is still  at  satisfactory level.
Summary:
spark gap just is easy  way to  keep  Rx  -  Tx   energy level  if system drifts.So what is better  generator or spark gap?
It depends from how good and stable is your mechanical   structure of  Tesla Coil in terms of:
- mechanical rigidity
- heat  absorption and exchange
- stability  of top capacitor positioning
- rigidity of capacitive and inductive elements if your structure.
- preventivness (no  streamers, sparks all around)

Note: difficult  to  read but valuable information  is here if someone wants to play with spark gap.
but also ab out structure of Tesla coil and coupling
https://www.richieburnett.co.uk/operatn2.html
Wesley