"Eye of Sauron" Rotating long breakout point 2007

This uses a motorized 6 foot aluminium tube connected to the top of the TC. The sparks will come mostly from the end of the tube and will trace out a circle slowly (about 10 seconds per rotation). The effect is dramatic on a long time exposure where a complete ring of sparks will be seen . Motor is a 24 V aircraft control motor with solid reduction gears and a cast alloy casing run from a 12 V SLA battery after I toasted a 9.6 V NiCad.

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Above shows my 4 inch coil with the rotating breakout point in action and when stopped.

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A top view is even more dramatic in a 2 rotation 22 second exposure. The "Eye of Sauron". Yes, I did stand dead still in the 22 seconds. 6 Megapixel version is available for print media for a token charge for this and most of the photos here.

Lots of comments on Digg , Overclockers and Hackaday about this.

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Above left is the much larger "Expanding Eye of Sauron" using an 11 foot (3.3 m) extension. Note the sparks to the tree on the right. On the right is "Seen in the Eye of Sauron" with me in the spark free zone. The yellowish ring is some masking tape catching fire on the tubing join.

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Above is the setup shown stationary with power off then on. My wooden counterweight is on fire here.

"Aura of Sauron"

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And now the Aura of Sauron and the Sparks of Sauron. These are some of my best effect photos and are not "photoshopped" although they are long exposures. For these the Tesla coil is mounted 11 foot (3.3 m) in the air and the rotating rod is attached to a long beam extended out above me.

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Perhaps the aura of Sauron's ladder? (I have to climb up this to turn the rotation motor on and off)

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Above shows setup and testing. I wonder if I should have taught my kids CPR? In the 4th photo, note the elevated Tesla coil with the rotating connection above the ladder about 11 ft (3.3 m) off the ground. In the last 3 photos, my chain mail butchers glove is grounded both to the plate I am standing on (wet to improve conductivity), and to an earthed point nearby.

Next just add the Driza-Bone stockman's riding coat, a hired dreadlocks wig, army surplus boots and you have the effect at the top. I am also wearing the chain mail glove and some cycling gloves over that so the sparks can jump onto my outstretched hand.

Tesladownunders Car Theft Protection 2007

How about a "Sauron's Eye" for your car?

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My wooden counterweight is on fire here at the top of the coil. It's quite safe to be in the car although my son was apprehensive. This was a Hyundai Getz hire car (as I don't own one) and it still works. I did get extra insurance "in case". Of course a Tesla Roadster from Tesla Motors would be the ideal car for this or a De Lorean.

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Construction photos. There is a rod projecting out the top of the TC and the sparks will come from the tip of the rod. If that rod is bent so that it nearly touches the ground it will spark to ground. If you rotate the rod around the car it will form sparks as it traces out a circle. If you take a long exposure then the sparks will all be on one photo giving a ring of sparks.

Again, lots of comments and links on hundreds of blogs and sites including Digg, humorous caption comments on Autoblog, Russian (with 377 comments), and Japanese sites. In total 200,000 website hits and perhaps 1,000,000 people have seen this on other sites since Feb 2007.

Tesladownunders Car Theft Protection (red car version) 2007



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Above shows more of the same (but a different hire car), experimenting with lighting and clearer sparks which are better centered. The right photo is a shot of only 3/4 of a revolution. Well, you need a space to walk out don't you!

Tesla Car Theft Protection (video) 2007

At last the video. Had to hire the car on 3 different days to get lighting OK. The video is much less tolerant of low light unless the frame rate is slowed a lot. Budget was $300 for the car hire (plus pizza).

Windows media video above (3.3 MB). Slower start but higher resolution than the YouTube one below.

YouTube video. Lower resolution, faster start.

Playback speed was increased to 300% for the action scenes both to give a Charlie Chaplin, silent slapstick movie feel and to speed up the rather dull sparks in that light. I did try to randomly interpolate 100 frames (manually!) to give the effect of a uniform field but it wasn't convincing.

Actual rotation speed is about 10 seconds per revolution which is easy for thieves to avoid I guess.

I did night time shots with great looking sparks but there was severe motion blur with the reduced frame rate and you couldn't see the bad guy. The brightest sparks are to the dummy thief (stuffed with old blankets) who had a grounded wire in his torso.

Smoke was from a smoke generator controlled by Chris in the car and timed to smoke at the time of the sparks. It is the blue thing under the front bumper.

I wet the ground to intensify the sparks but didn't turn off the tap properly so there is a bit of a river through the scene.

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Some behind the scenes shots during production.

Swimming Pool Sparks 2007

Taken in our backyard pool. The salt water pool is very conductive like a big ground so there is absolutely no sensation. People associate water and electricity with danger. Like dropping the hairdryer in the bathtub. But the danger only occurs if the water forms a path to you then ground ie if you touch the taps, bath drain or wet grounded floor.



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The chain mail glove has a copper braid attached otherwise it would be a problem if I had my hand right out of the water. Only small sparks here as I don't want wild sparks onto my nose. Photo technique for the left photo was a flash PLUS a 0.5 second exposure to catch more sparks but still freeze the water ripples. The smaller point and shoot camera was a better shot from the end of the pool as it shows the TC. Water was 17 C and not pleasant. I used a 12 inch loudspeaker magnet as a divers weight to allow me to sit on the bottom. The right photo has a sort of Matrix feel about it.

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The photo above shows 100,000 volt sparks onto me in the pool wearing a "tin-foil hat". It is made of aluminum foil and tape on a aluminum rod support. The back of the foil goes down into the water and is a low inductance path to the water. I also have two solid wires into the pool. There is no sensation at all when sparks hit me. Not shown well are the fine protective steel wires that protect my face.

"Tin foil hats" originate from those rather alternative people who believe that it protects aliens from reading their minds. Some guys at MIT even did a scientific study to show it does not protect from all radiation.

18 inch coil 2007



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Above top shows some shots of the 18 inch coil at higher power with a 3 foot rotating breakout point. Still not really firing well with strong 6 foot arcs and only occasional 7 and 8 foot weaker arcs. I didn't try retuning or altering coupling and I suspect the quenching is still not right. It should be capable of better. Bottom right photo shows an 11 ft radius rotating point with sparks extending over about 27 feet. This was a step towards a shoot in a dome shaped building later in the year.

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Above shows the coil in 2005 under development, with a primary of magnet wire taped onto cardboard. If you look closely you can see Mars about '2 feet' above the coil on the left.

The above photos were from a night shoot at the Gravity Discovery Center. Details here. The left photo shows the "Eye of Sauron" effect with the arc going directly to ground in a heavy power arc. But the spinning electrode is moving horizontally at 7 ft/sec. The ground arc is well formed it pulls an arc out from the top until it is nearly the same length again before it extinguishes and starts the process again. The power arcs are only 2-3 feet but the TC is running at 5-6 feet power. The middle photo shows the "triple 7" effect.

So why is the angle of the 7 so sharp? There are three competing forces. The main one is to stay in the hot ionized channel. Second is for the magnetic field effect to enlarge the angle outwards (think rail gun forces to push the arc out). This is counteracted by the electric fields encouraging the spark to take the shortest path.

It really is quite dramatic in action zap-stretch, zap-stretch.

The right photo again shows a full rotation which takes place in 7 seconds, perhaps 12 foot radius. It gives a whole march of about 40 "sevens".

Longest sparks 2007

This is a run with everything maxed out. The spark gap was running at its optimum of 400 BPS and the series blower gap was on full. I had a total of 0.11 uF of tank capacitance. I tuned things by hand and with the tuner to 36 kHz. The variac was on full and no ballast. No idea what the current draw was. I imagine 30 A plus. I have a tape measure on the ground which was only really countable in the high res photos but was set at 11 feet. The secondary winding length is 52 inches which gives a ratio of spark to secondary length of 2.3 which is fair enough.

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This is an 11 foot spark from my big coil. They only happen occasionally though. (something about the 3 longest sparks looks like a T. rex).

Tree of sparks 2009

This is meant to show the most sparks on a page. It is a 63 second exposure of sparks from a rotating breakout point that is progressively raised in a spiral so sparks extend from ground level up to a high of about 18 feet.



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Hoping my umbrella will protect me here. Note that this is the only double exposure with me next to the coil with it turned off on this page. The rest are all real time. I could have done it either way but didn't have enough help at the time.

Dalek cage 2007

This is a snug single person Faraday cage to enable the lucky person inside to get up close and personal with 6 foot sparks. It's shape is reminiscent of a Dalek from Dr Who. Remember "We will ex-term-in-ate". It is a simple walk in and walk out affair, open at the back.

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It is constructed from fencing wire and a hanging basket planter. It is earthed and should be safe as long as you don't stick your fingers out. I am standing on the earthed section. Somehow the 3 foot sparks in the left photo look better than the 6 foot sparks on the right. The sparkles are from some steel wool on the cage. It is not really as impressive as you might think as the sparks are largely end on. I have high efficiency earmuffs on and my glasses have a UV filter. The brim of the "pork pie" hat lets me know when my head is getting too close to the cage and also keeps the iron sparkles out of my eyes. There is a slight tickle of high voltage if you touch the cage lightly due to the voltage drop over the full height of the cage which is part resistive at the high currents and part inductive. There is only minimal sensation when using the glove which has two separate earths to the cage. I also lean on the cage as well with the glove.

I can also use it with my chain mail glove and I also have a little neon light a pink light saber (but knife sized).

This was made for a video which has been shot for a BMW ad, more later.

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This is the view from inside the Dalek cage. Difficult to get a good shot even with a wide angle lens. Spark length is about 4 feet coming to about 4 inches.

Honey... there's some electrical interference... 2007

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Left photo is titled "Honey... there's some electrical interference..." The mobile phone actually works fine, just very hard to hear. The right photo shows that you don't need the cage - sort of. The chain mail butchers glove has dual earth wires and I am holding a small neon light.

Multi-colored sparks 2007

These are some preliminary sparks taken on my ignition coil setup to demonstrate multi color effects.





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These are simply done by taking a long exposure (6 seconds) and manually placing different colored filters in front of the lens at different times during that exposure. The next step was to make a motorized system for some special effects coming up to simulate a famous fictitious Tesla coil.

I have now made a color wheel to allow rapid rotation of the colors or manual rotation. This simply gets placed in front of the camera.

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The results with a Tesla coil are to give sparks that are different colors. I am hoping to get green and other colors as well. Each quadrant is held by one screw and slides out.

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Left photo with a 1 second exposure, shows the some shots at dusk. Right photo with a 2 second exposure shows the various colors seen when the sparks are firing.

Now the good ones.



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This shows red sparks. This effect is created by taking a normal white flash shot first to give the correct white background, then switching to the red filter and running the sparks for 10 seconds or so while the camera is recording. It is all one single exposure and is what the camera sees, not a photoshopped effect added later.

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This shows multicolored sparks. This effect is also created by taking a white flash shot first to give the correct white background then spinning the color wheel to get different effects.

6 inch coil (the best ones)

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The 6 inch coil has performed better than expected with sparks reaching 8 feet (0.5 million volts). The left photo above shows 8 foot sparks to the closest point of the ladder. This is with a large topload and a tank capacitance of 92 nF (0.092 uF) at a power in excess of 5 kVA. A lot of smoke comes from my spark gap at runs of over 5-10 seconds at the highest powers. I suspect it is metal oxide from the tungsten stationary electrodes and the brass dome nuts and steel bolt heads that form the rotary electrodes. There was no sign of any polycarbonate frame or Tufnol wheel overheating. Despite the leaf blower cooling, the tungsten rods become hot enough to have a visible glow though the yellow polypropylene box after turn off. The 8 foot (96 inch) spark is exactly 3 times as long as the 32 inch secondary coil that generates it.

Predicted maximum spark length by John Freau's formula for 3 kW is 1.7 x sqrt 3000 = 96 inches. For 5 kW it is 120 inches. These seem to be most accurate for large (24 inch diameter) coils. A recently proposed correction by Dr Resonance gives spark length for a 6 inch coil = 0.85 x {1.7 x sqrt (power)}. This would suggest spark lengths of 79 inches at 3 kW and 100 inches at 5 kW.



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Earlier photos reaching up to 6 feet with a capacitor of 48 nF and a smaller topload at a power of about 5 kVA. They are 10 second exposures showing a variety of types of sparks and streamers. Lots of ground rail strikes resulting in arc-overs from the primary (the bright spot in the right photo). These improved with a smaller toroid under the larger one. In these early photos, It is all supported by a stylish barstool and is precarious, particularly as the toroid is supported by a heavy 12 inch loudspeaker frame including magnet.

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This 10 second exposure demonstrates the shaping of the high electromagnetic fields around the main coil that directs away them from the axis of the coil. The strong wind at the time shows the multiple sparks going down the initial ionized path of each main strike (banjo effect). This is best seen on the enlarged view.

4 inch coil 2003

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A shot outside the shed with the smaller coil (above).

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These are from a demo at a Fete at our local high school in March 2003. This is my first public display and used an 8 ft square faraday cage constructed out of angle iron and chicken wire. The Fete had a medieval theme so the theatrics involved Merlin the magician giving a magic class demonstration. Then, using a butchers chain mail gauntlet earthed to the cage, I put my hand into the cage and turn on, giving the effect of lightning bolts coming from my hand which is close enough not to show any other streamers. The 'lightning' finger had a high intensity blue LED pulsating inside the gauntlet. I then disappeared and changed into a scientist lab coat and gave a more contemporary explanation and a more conventional display with sparks to the cage 3 ft from the edge of the toroid. Definitely a hands over the ears display.

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I need a bigger shed as I am running out of safe standing room! (above)

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Above are shots of the Physics Dept Tesla coil. The left photo shows 15 inch sparks from a 12 kV 30 mA coil. The coupling and tuning was wrong and there were some potentially destructive racing arcs along the secondary. The right photo shows a 36 inch spark from the 16 inch secondary using a 12 kV 110 mA transformer. It is a daytime shot hence the sparks are low contrast. There was an extra toroid to give extra capacitance as it had been tuned for use with a Faraday cage.

Mini coil

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Two inch sparks onto my hand. There is some motion artifact with my hand but not the equipment or sparks. This is done with a clear knowledge of earth paths and at very low power levels on a small coil with no toroid capacitance. Wetting my hand beforehand reduces the sensation to a mild prickle. This is potentially dangerous and should not be attempted on a large coil regardless of power input.

TC driving fluoro tubes 2009

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I have hooked up a string of six fluoro tubes to my rope between two trees 20 feet in the air. I grounded one end and they ran well above the TC with no direct connection. So how many can I do?

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I then hooked up a string of a dozen fluoro tubes to my TC. Worked fine but I wonder how much longer is possible? I have about 100 fluoro tubes (the hospital saved their dead tubes for me) and a long driveway.

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I have now hooked up 30 fluoro's in a 120 ft string and they work fine. Can you see 3 of me in the middle photo?

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A rearrangement of the string using about 19 of the tubes. Sort of dwarfs me and the TC. Note the rounding of the picture at the corners with the limit of my wide angle lens. I had separate lead in wires from each side of the fluoro string to a block of wood that the spark in the right photo is striking.

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Here is a direct strike to the glass envelope of a fluoro which punctures it and over the next minute or so it stops working as air enters the tiny hole.

Michelangelo Creation of Adam 2009

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The concept and hands for the above photos were provided by Graeme Minchin from Michaelangelo's Creation of Adam. Graeme is one of the organizers of Photo Night 2. Still not entirely happy with them re angle of Adam's hand and exposure. The blue lens flare was a problem but doesn't detract too much. It is a problem with sparks which are high intensity on a jet black background. I had to light the hands without allowing any light onto the trees in the background.



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An animated sequence showing the "Creation" sparks in action.

Tesla in the moonlight 2009

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A simple shot of Tesla coil sparks framing the full moon in the background.

Wide angle sparks 2009

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Sparks here jump directly onto the camera cage. The camera is in a protective cage and the wide angle lens captures most of the 7 foot spark on the right. The left spark jumps to an aluminum tube just a foot or two in front of the camera.

Umbrella 2009



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Sure, umbrellas protect you from lightning ...

***** My real tip for all coilers *****

Everyone wants the biggest sparks - right?

My opinion: Don't think of a TC as just an exercise in getting the longest sparks.

My longest spark photo on my index page is about the 43rd photo/video down because it doesn't matter.

Spend money on a better camera/video/flash/tripod. Do something different, take some fabulous photos.

Google "Tesla coil" images. I currently have 20 of the top 100 photos there. As it happens my longest sparks picture is about number 100.

Many are of sparks or streamers are only 1-3 feet long but in the context of an Xmas tree or car thief protection or sparks in a pool that is fine.

All of my techniques are easily reproducible and were trivial compared with the original construction of the coil.

After years, I have still not seen a decent rotating breakout picture done by anyone else.