Rotary Spark Gap Tesla Coil

[HighVoltageProjects]

sweet coil would love a rotary gap for mine !!! they just cost so much .iv got some 9 inch diameter pipe for my next one just need a few more MOTS and a bigger shed

[SeanTuckerBrett]

Agian thanks, you have helped me out alot. what kind of power supply would i need for about say, 5 feet sparks? i am willing to buy some more NST"s...

[SeanTuckerBrett]

Thanks for the help! Do you think i will be able to get about 6-7 foot sparks with the two 12Kv 30ma transformers in parrallel and a 8 inch wide by 45 inch in lenght secondary if i tune it correctly?

[HVHighjinks]

@SeanTuckerBrett

No problem! :) I'm thinking you will get about 3 to 4 foot sparks from it. That's scary enough though. :P

You could always throw more power at it. That would need better equipment though. The space and line power needed to safely run a coil that can do 7 foot streamers is prohibitive. It can be done, you will need some hardy equipment though. Remember to be safe, and don't touch the coil or the sparks when it's powered on or even plugged in. Unless you like the dry look :P

[SeanTuckerBrett]

Very nice coil! btw i have a question, i just finished my rotary spark gap yesturday and it worked for about 10 mins but then all of a sudden it just stopped. So now it will just arc everynow and then. Do you know why? need help...

[HVHighjinks]

@SeanTuckerBrett

Hmmm. what is your setup. Type of transformers, caps, ect... I Have a suspicion the problem is your transformer, if it is an NST. They are prone to breakdown from internal arcing when used to power tesla coils. Especially if the coil is out of tune, or not setup quite right. Just of the top of my head though. :P

[SeanTuckerBrett]

@HVHighjinks I have a 12,000 volt 30 ma NST. And 12 cornell dubiler 942 connected in series. Looks like its the same ones you have. My secondary is very large, its 8 inches long by 48 inches in length (4 feet).. i do have a safety gap but no terry filter. i did manage to fix the spark gap.... the electrodes were two far apart. But im only getting MAYBE a foot at the most... thanks for the help!

[HVHighjinks]

@SeanTuckerBrett

Yep. Same caps for sure ! You should add another 12 caps in series with the ones you have, or add another 12Kv 30ma NST. That will bring the caps to a full charge. Adding another NST in parallel would be the better choice. (cheaper and bigger bang)

What gauge is your secondary wire, and how is your primary coil constructed ? (material, length, flat, cone, ect...).

Just trying to find out if it is tuned right. You may need to lengthen or shorten the primary.

[SeanTuckerBrett]

@HVHighjinks Okay cool i will get another NST! Secondary is 24 guage. My primary is cone shape, and its out of copper tubing like the usual. I have alligator clamps for my taps. The primary is 50 feet long.

[SeanTuckerBrett]

@HVHighjinks Okay cool i will get another NST! Secondary is 24 guage. My primary is cone shape, and its out of copper tubing like the usual. I have alligator clamps for my taps. The primary is 50 feet long...... it is 1/4 inch.

[MrStemkilla]

your secondarys are arcing to each other cover them with enamel coating before it gets worse

[HVHighjinks]

@MrStemkilla No, worries it is just a reflection on the lens from the spark gap. Unless you are talking about at the top of the coil. Witch has been fixed. Thank you for your input :)

[MrStemkilla]

@HVHighjinks yes i was talking about the top. goof to hear you fixed it before it got too bad. where and how much did you get your magnet wire from? and i see that you make several coils so far. can you box in your spark gap to make it as quiet as possible the sound just the coils make is spectacular ... did you get your best resolts with rotary spark gap or with the pipes?

[kappe9000]

Really nice work. It's the most impressive I have seen so far.

[crafter2u]

i wonder if that would work in reverse as a collector?

[ArduinoAlan]

how did you ground the secondary coil?

[08Kutt]

like more 1mV !!!

[TeslaNick2]

Very nice coil and great performance, definitely A-grade...

I did notice that your coupling is quite tight, I have discovered that looser coupling definitely works better on smaller coils, somewhat counter-intuitively.

[HVHighjinks]

Ya, the coupling is about as tight as it can be. If it were any tighter it would be prone to breakdown between the primary and secondary. I was going for the most bang for the buck. That way it could be powered by a regular 120V 15A outlet.

[morpher44]

very nice construction. Excellent -- and frighting.

[Depthhider]

What is the back box the one with sighn, EMI RF filters?

[HVHighjinks]

It has 3 PFC capacitors in it that total 180uf. That should make the power factor corrected to about 54%. I'm going to add one more capacitor to it for better correction soon. (going for 90%)

[gmondrax]

yeahh.. very nice construccion... But ... what happen if FP is not correct, performance goes down, low arcs, resonance can't be match ....what/???

[HVHighjinks]

There will be a slight drop in output, and there will be a slightly heavier load on the variac.

[gmondrax]

ohhhhh!!! I hadn't idea that happened on tesla coil!!!!

Thanks!!!!

[supercoolcat111]

What is the 10" diameter sphere mae out of

[supercoolcat111]

What is the 10" diameter sphere made out of

[HVHighjinks]

@supercoolcat111 Just polished stainless. Ikea salad bowls work well too :)