Back in 1994 when I was working on my Mandela Coil which the forums currently call the Starship Coil, I needed to isolate the resonant action of the top load and the third coil, this led me to designing the Crown Coil. On paper the Crown coil was promising, it was only after building one of the versions of the Crown coil in 2011 that I was pleasantly surprised on how well it performed.
I hope these pictures help you make a version of this coil, just remember ***the outer vertical winding’s end at the tube*** each one joins to the spiral coil at the top and at the bottom, they do not go through the center of the tube as per the diagrammatic picture above.
As all the researchers in the forums and Tesla groups are discovering the inductive action of a Tesla secondary will encompass the tertiary coil, unless it becomes decoupled from it. Using a sphere as a top load will not be enough, a toroid will allow this differentiation and decouple so it can drive another load without affecting the impedance of the secondary. The Crown Coil also acts like a toroid and a tertiary coil in one.
This is an experimental design and could be vastly improved given the right recourses. all the data is preliminary and not complete. If you choose to copy this design please give due credit, regards Arto.
The coils inductance values are in series for six strands and paralleled for two groups. The capacitances are a lot harder to define and I have only presented the tentative values I gathered from measurements.
L1 = La1+Lb1+Lc1+Ld1+Le1 = 3.5776 uH = L2,L3….L12
L16 = L1+L2+L3+L4+L5+L6 = 21.4656 uH
L712= L7+L8+L9+L10+L11+L12 = 21.4656 uH
L16 + L712 = 42.9311 uH
Inductance in parallel L16 and L712 = (L16 x L712)/(L16 + L712)
L = 10.7328 uH
C1 = Ca1+Cb1+Cc1+Cd1 = 2.975 + 8 + (2*((1/220)x6))/12 + 8 = 25.09 pF = C2.C3…C12
C = C1 *12 = 301.03 pF Capacitance in parallel
Note: Cc1+Cc2.+Cc3+Cc4+Cc5+Cc6 = 1 / ((1/220) x 6) = 37.66 pF Capacitance in series
Using an Oscilloscope and a signal generator I found the resonant frequency to be 2.8 Mhz very close to my calculations, I also found lots of harmonics above and below 2.8 Mhz
0.7 *
1.4 ****
2.8 ********** Octave 0
4.2 *
5.6 **** Octave 1
7.0 **
8.4 ***
11.2 *** Octave 2
22.4 *** Octave 3
As you can see by the list the electrical resonant notes are easily seen when sweeping the frequencies on my signal generator. The octaves are pronounced and a few other notes are also seen.
2.8 Fundamental
4.2 5th
5.6 1 st Octave
7.0 Oct + 3rd
8.4 Oct + 5th
11.2 2nd Octave
22.4 3rd Octave
I connected the Crown coil on top of my experimental Tesla coil secondary and ran it at 220Khz(1/4wave), it improved the spark length by 100%. This frequency was not concordant to the Crown coil, still it did show me I was doing something right.
After re-tuning the primary coil to run at 345Khz (pi/2 * Clight) , normally a Tesla coil will not work properly if the frequencies of the primary and the ¼ wave secondary are not set correctly. I was stunned that it worked and with a vast improvement of the system. Not only was the Crown coil getting pumped at a lower Octave = 2.8Mhz/ 8 , the coil was running at a super-luminal velocity!
Clight = Velocity of light = 299792458 mtrs per sec
Clight * pi/2 = 470912891 mtr per sec
Normal frequency of coil = 220000 Hz as per ¼ wave resonant Tesla coil
Additional frequency of coil = 345575 Hz as pi/2 x light velocity
After months of testing the crown coil in different situations, I decided to put a aluminum leaf electroscope on top of the Crown coil. This was an interesting experiment, as I observed the aluminum strips pulsating at about 0.25 Hz , I filmed this , but the quality was not clear(rushed arrangement), I will still post it.. An observer walked into the room had noted he felt a pulsing force as he walked towards the coil. I will conclude this a electrostatic pulse just as Tesla described in one of his arrangements. The driving system of my Tesla coil works nicely at about 100 watts (Variac 160 v * 0.625 amp)(NST 8000 v x 0.0125 amp), producing 150mm streamers, for hours if required. I have pushed the system to 400-500mm ungrounded streamers, but I found this unnecessary for experimental work, as things will start to fail if I run it for long periods.
As this is only the beginning of another journey of discovery, I am glad to share this with all who will follow the progress. The evolution of this coil will be interesting as the intensity of the charge increases as I tune the system, so as I redesign the Crown coil to resonate at different frequencies the tuning will become less critical. I will be eventually make to order a Crown coil to suite any Tesla Top load/ Third coil combination.
Adding other components to the crown coil such as a parabolic dish will make for some interesting experiments. I could direct the high voltage electrostatic pulses at any give direction. I have been carefully crafting the mold for it, the first few are very successful as Satellite dishes, Audio focus and radio astronomy projects. The parabolic dish is called the “The RAT Antenna” , this is a 600mm spun aluminum dish that is available for purchase from me, just email your inquiry, I will only ship in Australia.
This work here will be in my second volume of “Talking to the Birds”, the first volume is available now.
Artojh's Renderings 