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2023-11: Warosu is now out of extended maintenance.

/diy/ - Do It Yourself

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508002 No.508002 [Reply] [Original]

Have been building this up over the last couple of years on and off. Its getting quite serious!

http://www.youtube.com/watch?v=AUQeDqUhI3g

Some pics of the internals: http://imgur.com/a/0jgxR

Since those pics were taken, the rotary spark gap has been changed to asyncronous, with larger electrodes, and a larger topload thrown on top.

>> No.508030

bump

>> No.508034

>>508002
how are you powering it?

>> No.508037

>>508034
Dual MOTs (Microwave Oven Transformer). Unballasted, wired with parallel primaries, series secondaries. About 4400kv@300ma

>> No.508039

Holy FUCK, please tell me your behind something... that shit looks like it would kill you

>> No.508045

>>508039
Probably wouldn't kill me, but definitely would NOT want to touch the output.

I'm about 8ft away in the bottom right corner of the vid.

>> No.508050
File: 647 KB, 344x193, 1323094117154.gif [View same] [iqdb] [saucenao] [google]
508050

>>508002
neat as fuck OP

>> No.508058

>>508050
Thanks!

>> No.508167

>>508002

Definately one of the more impressive contraptions on /diy/ recently.

Do you have any plans for what you will be using it for?

>> No.508187

No faraday cage like a boss! Pretty sweet man!

>> No.508191

>>508002
Could you tell us how much you've spent? on Material...not energy.

>> No.508210

Looks awesome, but having all those things around doesn't looks very safe...

>> No.508587

>>508167
It'll be on display for Halloween. I'll be dressed up as Nikola Tesla

>>508191
I'm into it about $600-700

>> No.508596

And here I thought that MOTs weren't suitable for tesla coils.
Love it, OP.

>> No.508605

>>508596
A single one does not work well with a static gap due to its low voltage of about 2kv. The gap doesn't work well as it has to be so close together for it to spark. However a pair in series for 4kv, with a rotary spark gap works REALLY well!
My coil has 2 MOTS wired with parallel primaries in opposing phase, and series secondaries. No ballast, no filters. They are bulletproof, and when the coil is tuned well, they barely get warm.

>> No.508618

>>508039
>>508045
I mean that is amazing, just would scare the shit out of me lol

>> No.508684

>>508618
It is quite scary in person. Its EXTREMELY loud and intimidating.

>> No.508687

Would be hilarious if it caught the parts washer on fire

>> No.508703

>>508687
Thats a bead blasting cabinet.

>> No.508710

It keeps hitting your bike and there's a cord next to it, does that not cause problems?

>> No.508721

>>508710
That cable is unplugged. It is however near a ground, so it arcs through it to a ground not seen in view.

>> No.508734

My electric bill is crying even though it is likely hundreds of miles away.

11/10 though. Microwave transformers are magics yo. Turn it into a welder after Halloween.

>Captcha: electrical tionigja

>> No.508746

lol @ the arc going directly to the electrical cable

safe4sure bro

>> No.508747

>>508721
ok but please tell me that area is well ventilated at least...all the ozone buildup can kill you

>> No.508807

>>508747
I open the garage door during extended runs

>> No.509203

>>508587
>$600-700

Shit, that's barely anything.

>> No.509230

>>509203By trade I am a freight recovery eBay re-seller. I find a lot of my parts DIRT cheap at auctions. Most of the money is in the capacitors, and the lower toroid.

>> No.509231
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509231

>>509230
Cool, post your ebay store, let me look your shit

>> No.509246

http://stores.ebay.com/dasherdeals

>> No.509632

One last bump.

>> No.510508
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510508

>not building a plasma speaker

you are so close

>> No.510509

>that sound
I haven't heard anything so awesome before in my life.

>> No.510565

>>510508
It is really easy to add music/sound to a Tesla coil to turn it into a speaker.

http://www.youtube.com/watch?v=0sne_uI2Yq4

>> No.510631
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510631

>>508002
>>508002
>>508002
>JJ on /diy/
mfw

>> No.510636

>>510565
>It is really easy to add music
not if he's using a spark gap, you need a solid state driver for that

>> No.510658

>>510636
I don't see that being a problem either. It is all entry level EE stuff. It just looks impressive.

>> No.510776

>>510565
Maybe someday I'll convert it to a DRSSTC, but its not cheap, and its not entry level EE.

>> No.512488

is OP still here?

>> No.512739

>>512488
I am

>> No.514154

I lied... Another shameless bump..

>> No.514169

clearly fake

>> No.514395

>>514169
clearly..

>> No.514590
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514590

bump with content

>> No.514592 [DELETED] 

>>508002
Whats happening here?

>ntdocnn peach

>> No.514595
File: 1.03 MB, 2376x1584, 1376451188518.jpg [View same] [iqdb] [saucenao] [google]
514595

>>508002
Whats happening here?

>formless hisoops

>> No.514602

>>514595
OP clearly addressed that earlier ITT, after other anons clearly addressed it to him.

Also did you post the captcha on purpose? If so you are truly in league with the worst of 4chan.

>> No.514639
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514639

>>514602
Are you referring to
>>508710
and
>>508721
If so this is hardly clear and does not even mention the arcing in the ceiling. If not kindly reference to what your are referring or GTFO.

>> No.514643 [DELETED] 

>>514602
U mad bro?

>> No.515113
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515113

>>514595
That's me deciding I'm not going to run it indoors anymore.

>>514590
I recognize that smiley face on the xformer :)

You should find a few busted microwaves and start messing with resonant triple mot arcs. Check this out:
http://www.youtube.com/watch?v=qKSn8OkBeQg&t=8m

Keep the mcirowave HV capacitors for resonant runs.

Side note, this week I'm working with a local aluminum spinning company to try and get a proper 6.5"x26" toroid to replace the ducting on top. No more breakouts, for even longer streamers!

>> No.515121

that is fucking sweet.

>> No.515192

whats the magnitude of consumption for something like this? I have a 50A@230v breaker in my workshop.

>> No.515291

>>515192
My coil is running off a 20a 120v breaker. It pops after about 20 seconds. I measured current with a clamp meter and see it spikes up to 80 amps momentarily on ground strikes.

>> No.515323

>>515291
Good info to know.

>> No.515947
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515947

Asyncronous spark gap. Made from a big DC motor I had laying around. 6" rotor made from 3/8" CE Phenolic. 4 flying 1/8" tungsten electrodes. 2 stationary 1/4" tungsten electrodes. Speed is controlled with a small variac running a transformer which output is rectified and smoothed with some lytics I had laying around.

>> No.516376

In my 6+ years of lurking 4chan occasionally, this is the coolest shit that I've come across.

>> No.516382

>>508002
did he died?

>> No.517304
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517304

Here are a few pics of the MMC capacitor bank. Capacitors are Cornell Dubilier 942c20p15k-f. 10 strings of 8 capacitors for 188nf @ about 8kv AC. I have since removed 3 strings to bring the capacitance down to 131nf.

>> No.517305
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517305

>> No.517306
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517306

I may end up putting the 3 strings back in to increase current capability

>> No.517520
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517520

>>515947
>>517304
>>517305
>>517306

>> No.517851

Bump for more pics

>> No.518027
File: 1.81 MB, 3264x1840, 130804-IMAG1838.jpg [View same] [iqdb] [saucenao] [google]
518027

This is the dual MOT supply

>> No.518255

>>518027
>My coil has 2 MOTS wired with parallel primaries in opposing phase, and series secondaries.
Are the secondaries in series in this pic?

>> No.518533
File: 2.10 MB, 3264x1840, 130805-IMAG1843.jpg [View same] [iqdb] [saucenao] [google]
518533

>>518255
Yes, the cores are connected together with a strip of copper behind them.

Here's a pic of the primary

>> No.518534

>>510565
I have heard this done but with much clearer sounds. The coil was driven by a collins AM broadcast transmitter.

>> No.518557

>>508002
Cool as fuck anon, what's the cost for usage and materials? Just an estimate

>> No.518565 [DELETED] 

do you have plans to make our owns ?

>> No.518566

do you have plans to make our own ?

>> No.518594

>>518533
Is the grounded outer ring a complete ring or open?

>> No.518600
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518600

>>508002
make a proper plasma speaker they are cooler than tesla coils, more challenging, and have a use. If you spent all this money for a tesla coil why not a plasma speaker

>> No.518608

>>518600
How's the sound quality? I mean, atmospheric pressure plasmas tend to be somewhat unstable and they generally hiss.

>> No.518623

>>518608
sound quality of plasma speakers are amazing if you do it right, but don't expect bass. low budget and a shit circuit will get you shit sound. its more of the novelty.

if you are referring to tesla coils modulated to make sound, then those aren't plasma speakers.

i'm talking about arc type speakers like this
http://www.youtube.com/watch?v=ISA4sXOyyQI
http://www.youtube.com/watch?v=cEeWtBAE5LY
http://www.youtube.com/watch?v=NeIAkKmUfn4

>> No.518638

>>508002
That is very high voltage and very little current right?

>> No.518654

Rating = Awesome

>> No.518686

>>518623
The first one was pretty bad. The speakers didn't just hiss, they also arced at low frequencies. It also sounded like there was cross modulation between the power supply frequency and the audio.
The second was better, but it still hissed and the changing arc length (unsurprisingly) seemed to change the volume.
The last one might've been better than the others, but it was difficult to tell from the video.

>> No.519344

>>518594
It is open, else it would produce eddy currents and suck power from the coil

>>518557
I'm into it about $600-800

>> No.519345

>>518638
Correct. But this one is putting out some decent current also. You certainly don't want to touch.

Stuff catches fire pretty quick.

>> No.519391

>>518600
Apples to oranges.
Because I wanted to build a Tesla Coil, not a plasma speaker. Plasma speakers are entirely different, and are quite trivial. NOT any more challenging, especially comparing it to a coil this size.

I could toss up a modulated flyback driver for use as a plasma speaker in a couple of hours on a breadboard.

How is a 2" arc that makes music "cooler" than scary 5ft 120db streamers?

My Tesla coil gathers crowds whenever I fire it up outside.

>> No.519393
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519393

My HUGE variac I am using to control power. Specs unknown, but it should handle at LEAST 30amps @ 240v

>> No.519440

>>519393
Jesus, where'd you get that at? I want one.

>> No.519441

>>519391
>>518600
You can use Tesla coils AS speakers already.

https://www.youtube.com/results?q=Tesla+coil+music

It shouldn't be all that much to modify an existing one to do this.

>> No.519482

>>519441
>>518600
>they are cooler than tesla coils
PROTIP: they are tesla coils
>more challenging
{{Citation needed}}
>and have a use
vs a normal set of speakers?
{{Citation needed}}

>> No.519499

>>519441
Although the general principle is the same, they are driven completely different. Its quite a bit more complicated and expensive. That said, I would like to eventually make mine a DRSSTC someday.

>>519482
Flyback drivers are not quite Tesla coils. A Tesla coil by definition is an air core resonant transformer. A flyback is HV transformer, but not air core, nor always resonant (although they can be).

>> No.519503

>>519393
>Tesla coil by definition is an air

wow.
i jelly

>> No.519512
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519512

>>508002
rubber boots in motion

>> No.519793

Here it is recorded @ 240fps slow mo. http://www.youtube.com/watch?v=KYn-4vQCtXs

>> No.519804

Huh, can you get away with an auto-transformer? I thought the galvanic isolation of a regular stepup transformer was an important (safety) feature..

>> No.519808

Also don't these things throw out so much EMC and RF Emissions that you'll interfere with basically everything and get tracked down by angry Hams/FCC/Feds?

>> No.519810

>>518600
>>518623
Won't a plasma speaker make ozone?

>> No.519811

>>519810
All air-arcing electricity makes ozone.

>> No.519841

>>519811
Yes but unlike most other air-arcing things like tesla coils, a speaker you'd expect to have on orders of magnitude more often

>> No.519911

>>519841
This is only dependent on the power output. A small plasma speaker versus the OP's Tesla coil, well the Tesla coil will output a ton of ozone more than the plasma speaker. If you have a giant plasma speaker then the opposite will be true.

>> No.520382
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520382

A couple of years ago my coil was featured on Hackaday, but its performance at the time was lacking.

http://hackaday.com/2011/11/08/a-tesla-coil-that-delivers-shocking-candy/

You can see some build details here:

http://www.dashfest.com/?p=350

Back then it was synchronous, and had a really crappy capacitor.

>> No.521416

Bump for moar

>> No.521469

>>508037
My brother had an orgasm

>> No.521470

>>508045
>300ma
>would not kill you

>> No.521479

>>521470
You can die from as little as 100mA

>> No.521480

>>508037
>About 4400kv@300ma
How did you measure it?

>> No.521642

>>521470
The tank power supply could DEFINITELY kill you. The output from the secondary would likely not.

>> No.521643

>>521479
>>521470
Also this: https://www.youtube.com/watch?v=8xONZcBJh5A

>> No.521651

>>521480
4400v, or 4.4kv, my bad. I'm talking about the dual mots, not the output of the coil itself.

The current is actually quite a conservative number I tossed out there. It probably peaks around 500ma.
Its currently powered off a 120v 20A circuit, which it will pop after about 10 seconds of full power. 120v@20A is 2400 watts. Output of the MOT's is 4400v, so 4400v @ 545ma = 2400w. Most runs are probably averaging 300-400ma

Measuring the voltage/current output of the secondary accurately is VERY difficult. Its not a constant voltage and varies immensely depending what the streamers are currently doing. Volts per inch of arc discharge does NOT apply to the RF output tesla coils as it does 60hz AC.

Just a educated guesstimate, its probably peaking around 700-800kv @ around 1-2ma

>> No.522569

This week I'll be upgrading the coil with a 2nd spun aluminum toroid. 6x24". It will replace the cheap aluminum duct work on top. I'll also be re-wiring the transformers for 240v operation. Streamers should gain a bit.