I love the use of a spent .22 shell. I now have a near limitless supply of one component to build this

YouTube’s copyright protection is out of control. Who the hell will listen to this video just because of the music? Plasma playback quality is far from good.

Can anyone upload it somewhere else?
On some not capitalist video hoster?

Ok, I submitted a copyright dispute. Hopefully that will help.

Do these emit xrays? I know crts are capable of it and have built in circuitry to limit exposure.

that is the coolest fucking thing i’ve ever seen in my whole life

Put an extra winding on the HV transformer and you can get rid of the gate drive transformer and the 10.000µF DC blocking capacitors.

Wow… I was actually thinking of following your first one. But now you just updated it, so now I wont have to have an ice bath to show it off!

@grenadier

Yeah, no problem. May be usefull if Youtube goes down :)

@Fallen
The drone you hear on Tesla coil audio is caused by the spark gap in the primary circuit which causes a relatively low square wave modulation of the high frequency secondary oscillation.

To hide the drone, keep the frequency of the ringing up above human hearing and more than 2x the max frequency of the sound you want to reproduce. 48KHz would work well.

@Grenadier,
I still have them, I ‘obtained’ (my manager told me I could keep them) them from one of my employers a few years back. I was working for an OEM in the RMA department, and these came back with some blistering between the fiberglass weave on the PCB. We decided scrapping them was cheaper than reworking(especially since IIRC the multiplier boards they drove got up to 100kV, so it was important that the insulating ability of the PCB wasn’t hindered.).
Unfortunately I don’t have the multiplier boards. I sure did repair a lot of them though :).
It was a fairly standard circuit they used, just a cockroft walton(sp?) multiplier, in parallel with a 1W 10MR resistor. There was also a second multiplier on some boards for filiments or something, I can’t remember. Oh and a couple resistors in a voltage divider to monitor the voltage out.
The boards had slots routed in them between HV parts, and everything was immersed in oil.
The company they were made for was CPI, but I don’t know the exact product/products it was used in.

I’m going to hang onto them as I’m a class D nut.

Honestly the real reason I haven’t went forward with it is ozone production. It’s nasty stuff, and I haven’t figured out a cost effective way of building the tweeters and doing away with ozone production. :) using argon or helium would be way too expensive.

@Fallen Actually since this one only puts out 10kv there is no ozone!

Singing arc (modulated carbon arc light), 1899:
http://120years.net/machines/arc/

The .22 brass just makes it that much cooler.

@Grenadier: Congrats on being featured twice on HAD in a single day, and still having a functioning server!

In case it’s useful, some options for AC output from a flyback:

1) Some people have successfully drilled/dremelled into their transformer just before the diode to tap into the unrectified output; but success rate seems substantially less than 100% (I tried once and failed).

2) Old TVs that use separate voltage triplers have no rectifier in their flyback. Exactly how old (and large) a TV you’d need, I’ve never found out.

3) Or just buy a new flyback without a rectifier. Check out “FLYEXP” at “www.amazing1.com/transformers.htm” for a nice assortment which includes some non-rectified ones. There may be other sources, it’s been more than a decade since I’ve looked.

This is the same premise as the Tesla coils that produce sound. Pretty cool.

@Chris, HAD traffic isn’t near server crippling potential even for a double post in one day, unless you self host I guess.

Yeah I’ve got a great server. I think engadget might kill it though…

@omgkittenz
Trolololololo.

@chris
I know that, In fact I’m using an AC FBT in my next project…

@ejonesss
After 30 minutes there is still not a hint of O3 in the air.

@SpiralBrain
I used the 250 fets because I had about 20 of them. I’m sue the are better mosfets that one can use, but it was all a matter of convenience for me. Besides, the 250′s are pretty hard to kill.

But can you build it for stereo? For use as headphones?

I think there’s a very easy test to detect ozone, it’s your nose, ozone is very noticeable and there’s little doubt if you smell it.
And yeah any spark makes some ozone.

@James Munns

didn’t i catch you making one of these at the hardware hacking village at defcon a couple years ago?

This thing has to produce a lot of ozone. I did a great deal of research on this exact subject, and after less than a minute you could clear smell the ozone the arc is producing. And really who wants a fire hazard stereo combo? Sure the blue light is mesmerizing for the first few minutes, but after that all you will be left with is a space full of stanky ozone.