ENERGY AMPLIFICATION

[TinselKoala]

In Tesla systems that "loose" or "rigid" terminology refers to the magnetic coupling coefficient between the coils, which is generally achieved by varying physical spacing between the interacting coils. To see the effects of varying the coupling constant on both geometry and performance, I suggest playing with the excellent Tesla Coil Calculator here:
http://www.classictesla.com/java/javatc/javatc.html
Load the "sample coil" and then look down the page at the calculated output data, and you will find the computed coupling coefficient and the recommended coefficient, then you can change this and look at the effect on the coil geometry (a "picture" of the coil appears at the bottom) and the resulting output parameters.
This calculator is why my TinselKoil VII works so well; it was designed using this calculator, and in the real coil, changing the coupling has a major effect on performance. A spark-gap TC will generally require rather loose coupling, which allows the secondary to ring freely between spark stimuli. Solid-state TCs which are driven at the secondary's resonant frequency will be able to use tighter ("rigid") coupling since the secondary is not required to ring freely as it is pumped cycle-by-cycle.

[TinselKoala]

By coincidence I have just completed a demonstration capacitive-discharge ignition coil circuit that illustrates several principles that may be useful to other researchers.
The system uses a 74c14 hex inverting Schmitt trigger chip to produce 2 oscillators. One gate is used for the oscillator proper and two more in series on the output to clean up and sharpen the rectangular pulses. The frequency and duty cycle of the pulses are set by the resistors and capacitor on the oscillating gate. One oscillator (3 gates) is configured to produce around 1100 Hz which is fed to the low-voltage winding of an ordinary center-tapped filament transformer. The high voltage winding then charges a capacitor bank / voltage doubler system. The second oscillator (the other 3 gates) is configured to produce a 3-4 Hz oscillation which is used to trigger an SCR which dumps the accumulated charge on the cap bank into the primary of the automotive ignition coil.
This single chip, dual oscillator with adjustable frequency and duty cycle (put in potentiometers instead of the timing resistors) can be used over a very wide frequency range and can be made to produce "beat notes" as some people in some other threads are trying to achieve with 494s and other arrangements. The two oscillators can be synchronous (phase-locked) or asynchronous as the maker desires. The general scheme of using the SCR to discharge the cap bank into a load may also be of use to experimenters.
This is not intended to be a high-performance system as I have constructed it, it is just a demonstrator of the principles involved.
Video:
http://www.youtube.com/watch?v=o4EHiXv_IXo
Schematic from the Bowden circuits website is reproduced below.
http://www.bowdenshobbycircuits.info/

[a.king21]

http://www.ebay.co.uk/itm/201019368766?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


Well, this is how I get 400 thousand volts.
It can be controlled by a tiny chip or 555 timer or other micro - processors.

[TinselKoala]

http://www.ebay.co.uk/itm/201019368766?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


Well, this is how I get 400 thousand volts.
It can be controlled by a tiny chip or 555 timer or other micro - processors.

400 kV is a bit of an "exaggeration", since the insulation on those output wires is only good to 1 kV or less. And anyone with experience with HV can tell you that a 2 cm arc between point electrodes is only indicative of a few tens of kV,  if that much. Between large spheres in dry air you can expect to spark at 30 kV per centimeter of gap, and with points you will need much less voltage to jump a 2 cm gap. These values are valid for DC and for AC to at least 300 MHz.

Feel free to demonstrate otherwise with this little, cheap gadget that claims to be able to spark across a whole 2 cm.  A true 400 kV will spark across 20 cm air gap, or even more.

http://www.tesla-coil.com/official-air-breakdown-voltage.htm

Some 300 kV sparks at about 20 cm gap:

[Bob Smith]

a.king21
Nice diagram and reference. Tito has mentioned that his setup involves three coils. My own feeling is that in its most basic sense, it consists of a primary coil, a resonating coil and a pickup coil.

A couple of things we need to be aware of
- that Tito has repeatedly spoken about balance. If we look at the Don Smith devices and some of their alleged replications, balance was a key issue for their builders. Coils need to be balanced to ensure their sympathetic resonance.
- not disturbing the dipole. We know that as soon as we begin to draw electrical charge from the resonant system, the frequency changes, and this destroys the resonance and dipole.  I believe the swbifi coil is a way around this problem.  See some of the comments this summer by Stupify12.

I also believe feedback via a diode is involved, and Dave 45 has been looking at this.  In my understanding, this could involve pulsing feedback from bemf back to the primary. Once you generate resonance in the primary, you have a secondary that can be brought to resonance and a pickup coil that will not disturb the resonance when used.

As for the zener, I'm not sure.. Wasn't there a song about it - Have you Zener? https://www.youtube.com/watch?v=ZxOBInMi3l0&feature=player_detailpage#t=88
Bob