There's a lot of conflicting information said by Don in his interviews.

What we need to remember is the devices were built many years before he had these interviews that describe their operation, and in between these years he has had a number of strokes, you then realize he is lucky he can talk at all in the interviews, his face is paralyzed down one side and as he talks he dribbles because of this.
He obviously has some trouble remembering exact build details as he stands there telling you a cap has one value and when the camera zooms in it's a totally different value.

I have not been able to verify the value of the large paper-oil caps he says they are 8uF 2000v but he also says they are wired in series, and in the pictures they are obviously in parallel.

Peter
 

I will probably try making my own litz wire coils and work on the basis of making a few sets untill i have the recharge level right.

but

before this can be done i need to design and build a cpu based HV inverter 1200-2400v 50Hz to 240VAC system

Hi Yucca

I have a micro electronics background from the 80's LOL so a bit outdated.
I have used C but normally for simple things like this i will use machine language and already have all the PIC development kit so will probably go with these as they come in anything from 6 pin upwards at very low £1-£2 prices.

I also was a Z80 pro  and designed quiet a bit of film animation equipment using them, shame really it's the one micro i have never returned to but have always loved the code structure of the good old Zilog chip.

I was a one man proto devolper at one point and always proto on my own pcbs, very fast turn around and a lot neater than breadboard ect.

Peter

Yer i have an amateurish light box and a tray for my devolper and acid LOL.

But with cad it's easy to knock it out fast, and if there are errors or design changes then there's easily a version 2, i tend to use mostly SMD these days because you can buy the res and cap kits for £20 and you have nearly all the components you will ever need all in a small compartment traym, also some of this stuff like my last Pulse controller worked down to 250ps res with fast rise times and it would be impossible to build without double sided pcbs and a ground plane.

I really do recommend anyone to work this way it's the only way to proto from my experience, you can spend ages getting a RF circuit going on plug board, but would never be in a position to transition easily to pcb because of the stray cap ect, and vero and breadboard is a nightmare if the circuit has buses or complex wiring.

 

Secondary cap is now confirmed at 0.047 6000 VDC

I can see 0.047 mF but to my eye it looks like 8000 VDC. Maybe you eyeballed it better from another angle though? Not that it matters as much, it's the capacitance val that's most important.

Hi Yucca
When i view a series of frames together it's 6kv, i agree it does look a bit like 8, i couldn't find a frame though that clearly showed 6.

I still say he didn't have more than 2kv on those caps as he probably used bipolar based inverter and this would have had trouble over 1200v, although i guess he could afford to drop a bit across the recharge coil, and he does state the paper caps are 2kv 8uF and they are in parallel.

I think he talks about using a spark gap to limit the potential on those caps as well to protect against over voltgae, infact this maybe the way to go for an initial closed circuit run, just use the SG as a load and run the recharge coils back to the gel cell via rectifiers, if it runs forever crack open the champagne LOL



 

This kinda explaines the hairpin!

A spark-gap transmitter is a mechanism for producing radio signals. It has been the primary radio transmission device during the early years of radio technology. It was soon superseded by other transmitters due to its discontinuous radio wave production and widely varying frequencies.

 
How a Spark-Grap Transmitter Works
A spark gap transmitter is basically composed of two capacitors (electrical apparatus designed to store electrical energy). However, the switch that ultimately forms the connection between the two capacitors is ionized gas (the air gap) that facilitates the passage of an oscillating current from one side of the transmitter (from one capacitor) to the other.

In normal conditions, the air gap forms a barrier between the two capacitors. To break the gap, a spark must be induced. To this end, the capacitor that is directly connected to a power source is charged with electricity. The electrical charge does not immediately dissipate because of an in-built resistor that 'holds' the charge.

After the electrical charge reaches the minimum threshold voltage, the electric charge passes through the resistor to the conductive electrode touching the air gap. This electrode subsequently releases the charge towards the gap and this ionizes the air within the gap; this forms a connection between the two electrodes at the gap.

This initial spark makes the air gap conductive and the pulse generates an electromagnetic wave in the radio frequency range (around 350,000 Hz). This transforms the spark-gap transmitter into a resonant circuit (an inductor-capacitor setup) where alternating current is conducted. This process is very similar to what happens when the negatively charged particle from the air touches the positively charged particle on land in a lightning flash.

Very soon after the initial spark, though, the wave weakens since some of the energy escapes though the antenna found on the side of the second capacitor and some are used up due to resistance. At a certain point, the ionized gas builds up resistance once again and the flow of current stops. Since the radio wave is weakened after a while, spark-gap transmitters acquired the name 'damped oscillation' transmitters.

A typical spark gap transmitter is powered by high voltage transformers feeding AC power. The latter allows the capacitor to charge quickly and in a fixed cycle which can be controlled to allow for 'pulsing' radio signals.

History of Spark-Gap Transmitters
In a way, spark-gap transmitters may have been the key to the development of wireless transmission. In 1862, James Clerk Maxwell predicted that electromagnetic waves can travel through a vacuum; in 1888, Heinrich Hertz used a spark-gap transmitter and a spark-gap detector to prove that the transmitter was producing electromagnetic waves - every time the transmitter sparked, small sparks were observed in the receiver's spark gap.

Guglielmo Marconi, inspired by the experiments of Hertz and others (including Nikola Tesla), was able to develop practical and workable wireless telegraphy using high-powered spark-gap transmitters. Though they could not be used for voice transmission, spark-gap transmitters still became the standard equipment for the military and the maritime industry.

@xee

Yes this seems to be the case with my basic tests I have preformed so far.  I have lots of ideas today.

On the circuit diagram you made...could you put 2 caps after the bridge that go from + - and then I doubled up to 4 coming off the spark gap.  I have been getting better results with this.

P.S. Are you working with a similar circuit at this time?