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LAN_403

Tesladownunder

Tue Mar 28 2006, 05:37PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Ronald Aug 09 2005

Showing the small coil running at 1.2Kw on the filament and aprox 2Kw in the coil

1143567438 10 FT14 Teslavttcronaldsparks1

Tesladownunder

Tue Mar 28 2006, 05:38PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Tesladownunder Aug 23 2005

This is the University of Western Australia TC which dates back 40 years. Made in Germany according to the nameplate. Apparently runs at 1Mhz but lots of problems with the Leyden jar caps. Not really sure of the performance or if it is working now. They want a new one so I put my hand up. Not sure if the wiring forms the best theoretical transmission line at 1mHz

Tesladownunder

Sun Apr 16 2006, 05:04PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

teslacoiler Aug 27 2005

Hi All!

This is neither my last coil nor my best one, is only the strangest configuration i use during the development of my "VTTCBIG" ( destroyed for scraping components for building my "VTTCBIG2Â°" and reborned as "Progetto Fenice" )

basically i made a vacuum tube coil with the standard schematic but i had some insulation problem between primary and secondary ( see this pic for details

)

so i decided to modify the coupling between coils and made a tesla magnifier. For the first time i use a separate secondary wound on a 25cm coilform magnetically coupled to primary coil, the base of this secondary was connected to ground and the end of it was connected to the base of tertiary coil with this configuration i solve the insulation's problems but i never get impressive outputs ( approx 10cm of streamers ), so i decide to made another change

i added many other turns ( and many other taps, 1 each turn, a boring procedure!!!! ) on my primary coil to made a sort of autotransformer, than i connected the base of the coil at the plate supply and at the tank capacitor, i made a intermediate connection for the plate and the tank capacitor and finally i connected the base of tertiary coil at the end of the primary coil.
With this circuitry the output was now quite well, the streamers was similar to any other VTTC but the sparks and arcs to ground was really hot and impressive, no way to doubt it since the output of the coil was in fact connected to the plate voltage!!!!!
of course, in this particular configuration the coil IS EXTREMELY DANGEROUS!, LETHAL VOLTAGES AND CURRENTS ARE PRESENT AT THE TOP OF DISCHARGE TERMINAL SO STREAMERS MUST NOT BE TOUCHED!!!!!!!!!!!
I decided to solve this new problem by using a big 1nF 14kVrms ceramic capacitor inserted between primary autotransformer and tertiary coil, the output of the coil was now pretty safe but not entirely safe so is preferably to never touch the streamers again.

This is the final result:
After this experience i made a new secondary coil, i rewired the circuit as a standard VTTC and i tried to reuse the taps on primary coil as impedance matching transformer for the plate circuit, in fact the internal impedance of the tube is about twice the impedance of the loaded LC tank circuit and this impedance mismatching is adversely affect the performance of the coil. my VTTCBIG2 was finally borned, but this is an another story!

Tesladownunder

Sun Apr 16 2006, 05:06PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

NickBernsden August 30 2005

Here is the third and most recent tesla coil I have built.
It is a DC resonant charging rotary spark gap tesla coil.
It runs at about 2,000W and has produced a 5 foot discharge, although strikes are more often between 3 and 4 feet.
Power supply: 2 MOTs wired in series, center tap grounded, in oil.
Voltage Doubler: A two 35kV diode-sticks and 16 microwave oven capacitors to produce a pretty steady 12kV DC output.
Charging reactor: 4 MOT secondaries in series, I-laminations removed from cores to introduce an airgap.
D-Qing diode: 8 microwave oven diodes in series.
Spark Gap: <480 BPS rotary made from a 3600 rmp oven-fan motor. 8 spinning, 1 stationary electrode.
Capacitor: Cornel-Dublier MMC-- 2 strings of 15 caps for 30kV, 20nF.
Primary Coil: 16 turns of .25" refrigeration tubing wound on a 15 degree inverse-cone.
Secondary Coil: 25" tall, 4" diameter sch 80 PVC coilform. Winding is awg 22 over 24" for 1050 turns.
Torroid: Aluminum drier duct, 26" major diameter, 5" minor diameter.

You can see more about this tesla coil at

You can also see my other coils, along with other fun things like trebuchets, potato guns, robots, and jacob's ladders at

Below is a 2 second digital camera exposure of my DC coil running in my garage.

Tesladownunder

Sun Apr 16 2006, 05:08PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

NickBerndsen Aug 30 2005

This one is the second coil I built, during my junior and senior years in high school.
It is a standard AC rotarty spark gap tesla coil.
It is designed to run at about 6,000W (although I never pushed it past 4,000W). From this power, it produced 6' to 8' sparks.
Power supply: 10kW, 14.4kV distribution transformer.
Ballast: Sliding inductive ballast built from welding rods.
Capacitor: MMC 30kV, 20nF
Spark Gap: 480 BPS rotary from a 1800 rmp tredmill motor. 8 spinning and 2 stationary electrodes.
Primary: 100' of 3/8" copper refrigeration tubing. Flat spiral, 16 or so turns.
Secondary: 1100 turns of AWG 18 wound on a 8" by 40" sonotube (cardboard) coilform heavily coated in polyethylene.
Torroid: 2 aluminum drier duct torroids and another made out of corrugated drain pipe covered in Aluminum tape. All statcked on top of eachother.
Sadly, I didn't put a lot of (any) filters on this, and I think the coil killed my pig on the coil's first light. All I have are these screenshots from a video I took right before it fried. This was before I could accurately tap the primary or crank it up to full power.
You can see more about this, and my other coils at

Below is a screenshot of an arc to a ladder in my backyard.

Tesladownunder

Sun Apr 16 2006, 05:10PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Wirenut Sept 11 2005

This my second coil.
Power Supply: Unballasted MOT 6 pack, final 2 MOTâ€™s under oil.
Primary: (Used G. Hunterâ€™s design, but I was too impatient to cut tapping slots so I simply tap from the top) 14.8 turns .25â€ copper tubing spaced .25â€, 8.5" ID on a 24"x3/4" plywood disk.
Secondary: 6.25â€ O.D. pvc wound for 28.1â€ w/ 24awg ~1300t 201kHz (calculated unloaded)
Cap: Several large paralled home-made rolled PE under oil ~.1uF.
Gap: 733 BPS ARSG
Toroid: 7x24 & 3X20 (56.7pF calculated capacitance, brings Fres to 84kHz)dryer duct covered w/al tape.
Max. sparklength: 72" with breakout point to grounded target, Gap full blast, pri. tapped @ 5
Planned upgrades: .1uF MMC, SRSG, *X* spun toroid

Tesladownunder

Sun Apr 16 2006, 05:12PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Wirenut Sept 11 2005

Itâ€™s hard to take good pictures with a cheap digital camera while manning the coil controls alone. I Have video (Pics soon) of 72" direct strikes to a grounded target with bigger toroid & breakout point

Tesladownunder

Sun Apr 16 2006, 05:13PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Reaching Sept 11 2005

DRSSTC1

Resonant Frequency: 150khz

Primary: 10 turns of 6mmÂ² copper wire,on 16cm form, attached at 6 turns

Secondary: 11x45cm PP Tube wound with 0,3mm enamelled wire

Toroid: one small 4x20 and a big 8x30cm, alu coated

Driver: Steve Wards DRSSTC1 Driver

Fullbridge: 4x G4PC5OUD Igbts

Sparklenght: nearly 1,5meter or 5Â´ (seen in the Video)

Heres the new Video of the running coil,

Tesladownunder

Sun Apr 16 2006, 05:14PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Avalanche Sept 17 2005

I'll add mine, first coil and by no means the last.

It's only a tiny SSTC, self tuning, I think it is running at about 1Mhz here, and lighting tubes from only a 24vdc supply and a single MOSFET rated for 50V. I actually didn't expect it to work, I just noticed the corona discharge whilst attempting to determine the resonant frequency of the coil on the scope, so a working coil was a bonus.

Tesladownunder

Sun Apr 16 2006, 05:16PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Akota Sept 17 2005

My first coil. Started this about 2 weeks ago. Pretty typical design using 4 MOT stack, .03uF Maxwell 35KV cap. I know in the pic the strike rail is below the primary, but it didn't start that way. My primary was originaly flat but because of low output from being mounted to wood I added some plastic spacers and it pulled into an inverted cone. Anyway, I am getting around 3 foot streamers now. There are photos and video on my website

under the photon section. I am reworking the spark gap. Right now I am using a tungsten single static gap. It gives low output to start, warms up and output grows, then overheats, stops quenching and output drops. Also, everyone asks what the lights are for. I am using them as ballast for the time being.

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