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Well, it took a while but I found the reason for my insulation breakdowns.. "overcoupling" between the primary and secondary. I've now changed to a flat spiral shape with too much distance between the primary and secondary (I was paranoid of melting something again!!).

With that small alteration I'm now getting sparks up to 14cm long (constant). My coil is now as follows:

POWER SUPPLY - 12kv 30ma Neon Sign Transformer

CAP - 4 x 750ml beer bottles wrapped in tinfoil filled with salt water and brass rods through the tops for connection. They are dark glass, but my favourite beer only comes in dark glass so it'll have to do! They sit on a stainless steel conductor connected to the spark gap and the NST, in a beer crate (to help lessen shrapnel if a cap explodes).

SPARK GAP - Now upgraded to a series of nails poked through a large diameter of PVC pipe, allows easy adjusting of gap and improves quenching as I added a blower fan salvaged from a microwave oven. I keep it in a drawer under the main coil as they tend to be noisy and create copious quantities of Ozone.

PRIMARY - is about 6 metres of cat 5 network cable with all the wires shorted at each end, coiled in 9 turns with outside diameter about 45 inches.

SECONDARY - is hand rolled 24awg (I think, a friend gave me a reel of it (Thanks Marcus)), wrapped around about 3 inch diameter orange pvc with a total length of about 3 feet and approximately 1000 turns.

EARTH - is a 4 foot long hollow rod hammered into the ground with about 4in above the surface. (The hollow rod is great as you can fill it with water constantly running from the tap, which soaks a large area 3½ feet down). Good earthing is important if you don't want to kill yours and your neighbours electronics. My new setup doesnt interfere with tv either :) Michelle likes that part more!

No Choke or safety gap. My desk is too cluttered as it is.

Top load - Anything from the bare wire to one of serveral different doorknobs and I've even tried a snail (I let it go afterwards - Fare well Oscar!) Yes it was still moving on its own accord as well!

Current Spark Length = around 14cm. If I remember correctly from school it takes about 7,000 volts to jump 1cm. 14cm x 7,000 volts = 98,000 volts. Yeah baby, but that's the bit Michelle doesn't like now.

Well, this is the Secondary of my coil, in the photo you can also see the beer bottle capacitors and the Cat 5 network cable used as the primary.

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Well, you just can't have a page on tesla coils without having photos of sparks. I could sit for hours running this staring at the sparks, however I've limited myself to 2 minute runs max to help avoid the risk of killing my NST.

The top end on these photos is a very heavy brass doorknob. This gives greater spark length than a smaller, thinner doorknob I have, however the smaller knob promotes more streamer breakout.

The 3rd photo shows a spark travelling to a ground wire I have connected to a separate ground lead (Not to mains ground).

The bottom photo is the top end wire of the coil formed as a loop. The camera really just doesn't do it justice. You would never forget the sight of a tesla coil in operation, the dancing energy, the noise and the smell of O3 really leave an impression on you.

Most friends think it's static electriciy, and you have to be careful people don't try to put their hand on the top to see it their hair stands up! Yes, it probably will, even when you're lying sprawled across the floor of the workshop with smoke coming out of your ears.

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Ever read the fine print on a standard dry cell battery?

Danger may explode if recharged or disposed of in a fire.

I had to try, it was just too tempting......

Kids, Don't try this at home!! Even tho nothing bad happened this time, I'm sure they put them little warnings on them batteries for a reason, otherwise they'd just be wasting ink or something.

Interesting Note: I measured the battery on a voltmeter before I did this to it, it measured 0.95 volts. Afterward we were at 1.35 volts. I havent had a chance to test the current yet. It's on my "To Do" list which just keeps getting bigger.

I need another week off. Stuff-it, I need a year off. Paid of course.


My brother foolishly asked me to "Burn" a cd off . I had great pleasure doing that for him. He hasn't asked me to do it again. After a minute you end up with very pretty fractal patterns etched in the cd, however you also end up with a lot of (I'm guessing) aluminium particles everyehere. You gotta watch out for them, aluminium causes you to forget things and can short out your wiring as well.


I tried adding another couple of beer bottle caps, however performance was halved. Not sure why, perhaps I need more power to charge them. Dropping the number to 3 bottles had the same effect, so I guess I was lucky to hit it bang on with 4. I will eventually get around to making an MMC however that will have to wait until I rob a bank or something before I can buy the 60 or so capacitors that I need.

It looks real pretty lighting up a dead cdrom. If you take all the streamers lengths at any given moment I'm sure It would add up to a couple of feet!


LINKS A nice graphic page showing components and stuff. Another great site with heaps of info including MMC design.


Ps, if you kill yourself reproducing anything you see on this site... it's you own bloody fault and don't come screaming to me.


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