Tesla Coil Build Thread

[nospin]

What are you doing for a topload?

Your secondary with a 4x18 topload resonates at 248khz

the primary of the NST will bleed off the PFC caps
don't worry about that

 

[USAbro]

Top loads can be bought from eBay.

 

[nospin]

Top loads can be bought from eBay.

I made all mine, not hard

For the reinvented coil I already have the tubing and it will be a massive 8x32 beast
and resonating at a calculated 150khz

Toploads are a charging cap with a balance between to many breakouts and none


The 6x24 on the 4.25" V1

36" bolt in the mad scientists lab

 

[Down with Umbrella]

Ok, I have two 15kV/30mA NSTs in parallel.

For a top load I was first going with a high dollar spun toroid from EVR but they are a bit too pricy for the large one I wanted. AL drying duct was my second option. However thanks usabro ebay might be a great place for a used top load.
4x18 was what I was looking for.

 

[USAbro]

4x13-http://www.ebay.com/itm/4-x-13-Toroid-for-Tesla-Coil-Spun-Aluminum-Topload-/321584493080?pt=LH_DefaultDomain_0&hash=item4adfedf218
Pretty expensive though. For $329 you can buy an entire setup that produces 1.5 foot streamers!

Or this-http://www.ebay.com/itm/c-Used-Tesla-Toroid-29-x-5-Spun-Aluminum-/201238398852?pt=LH_DefaultDomain_0&hash=item2edabe4784
Even bigger than you want

 

[Down with Umbrella]

Thanks for the links, they are a bit much. I'm tore because I want a nice toroid but for something that can simply constructed I might got with cheap dryer duct with AL tape.

 

[Sigurthr]

Check out amazing1.com for toroids, still the best prices I've found outside of specials from John Freau.

 

[nospin]

Thanks for the links, they are a bit much. I'm tore because I want a nice toroid but for something that can simply constructed I might got with cheap dryer duct with AL tape.

Make your own

 

[USAbro]

New strange thing. I've been playing with the wraps on my mini tesla, (one I made before my big secondary, about 200 wraps of 30 awg on 6" of 1" pvc) and now that creates bigger arcs than my big secondary, around 1.5 inches! And to scale that to a big tesla coil thats 4' tall, arcs are scaled to about 1.5'.

Does anyone think I may need more capacitors. Right now I'm using two gravy jar capacitors in parallel with aluminum tape on the inside and out, no water. I think I may make two more and see if that's an improvement. What do you all think?

edit: oh and thanks for the link to amazing1.com

 

[The Lightning Stalker]

Probably. 2 jars isn't much. Your mini
coil just happens to be more in tune. A
bigger coil needs lower frequencies and
more tank caps. You also need to
experiment with where your primary is
tapped and raising and lowering the
secondary to get good arcs. All that is
called tuning.

How To Tune A Tesla Coil

 

[USAbro]

I'm having so much fun playing with this mini tesla (1.5 inch arcs) I can't wait to finish the bigger one (14" tall). The problem is the high frequency interferes with my moms digital TV waves so she keeps complaining.
Are there any cool experiments to try with it?
Also, I'm gonna be now building more caps. Monday is recycle day here and people throw out tons of jars.

EDIT: Is 10 gauge wire thick enough for a primary? My dad has 50' of 1/4 copper tubing, but it's his and I'm not allowed to use it.

And also, what would be the best configuration for a primary? How many winds do you think is good to start with? Should it be insulated wire or non-insulated wire?
How far apart should the primary wraps be?

 

[Sigurthr]

10ga is fine for low power primaries. Spacing depends on the voltage applied to the primary; if you have 10 turns and apply 10kV to the primary there will be 1kV per turn, so you need to space the turns so that 1kV can't arc across; roughly 15mm spacing. If you use only 5 turns and 10kV you need to space more, if you use 20 turns, you space less. Got it?

Get familiar with JavaTC. It's free, and highly accurate for modeling TCs. Just google it.

 

[USAbro]

10ga is fine for low power primaries. Spacing depends on the voltage applied to the primary; if you have 10 turns and apply 10kV to the primary there will be 1kV per turn, so you need to space the turns so that 1kV can't arc across; roughly 15mm spacing. If you use only 5 turns and 10kV you need to space more, if you use 20 turns, you space less. Got it?

Get familiar with JavaTC. It's free, and highly accurate for modeling TCs. Just google it.

So based on this, would a flyback be enough to power it? I'm looking for at least 4 inch arcs. I'd be satisfied for that. Understand that if I had money I'd buy an NST, next summer when my lawn business starts again I may but now, the flyback is all I have so could this work?

I'd say my setup is similar to this, except with out the NST. Trashy Tesla Coil a tesla coil made entirely from junk from dumpster diving

 

[Sigurthr]

8.48" is the theoretical maximum for a 9kV 8mA input power. That's ignoring all losses in the spark gap, any impedance mismatches, any coronal losses, any component losses (caps), all ohmic losses, and any tuning mismatches. So, yes, it is technically possible, but you've got a lot of homework to do to get 4" out of it. The single biggest source of loss you're likely to encounter is the capacitors. All DIY or low cost caps (leydens, beer bottle salt water, glass/plastic and foil, etc) will lose at least half the energy you put into them.

 

[The Lightning Stalker]

Would those be corona losses?
In all my homemade capacitor experiments,
corona loss seemed to be the biggest effect
by far. It would load the flyback
transformer down to the point where it
reduced the size of the arcs.

 

[upaa27]

He said he is using a 14w ballast so any loss is a big one