Comments on: Singing Tesla coils

By: shbazjinkens

shbazjinkens — Sat, 14 Jun 2008 09:17:38 +0000

These coils are DRSSTCs - double-resonant solid-state Tesla coils. They are powered with IGBTs, which limits the frequency to less than 20 kHz at best.

The reason for this is because they pass so much current - he wants those sparks as big as possible. These were 5 ft last I heard and they're not even turned up all the way because they're afraid to blow them before show season is up!

MOSFETs switch at a higher frequency but also have a much higher resistance. You can build a full-wave coil but your power is limited by what the MOSFETs can handle. If it is analog modulated there is A LOT of heat dropped, so even though the IGBT may be able to modulate at audio it should only be switched for heat concerns. If MOSFETs are pulse-width modulated like a class D amplifier it's not so bad but still nowhere close to 5 ft without massive MOSFET bricks.

The two links at the top of Steve Ward's site (the fella from Illinois) give a lot of info about the hows and whys with schematics.

http://www.stevehv.4hv.org/

They can be pitch-bent, like here:
http://www.youtube.com/watch?v=jH9gZBGFDmM

By: dave

dave — Sat, 14 Jun 2008 08:47:30 +0000

we had a very similar event this past year at our engineering open house (university of illinois).

it was spectacular. they even played the quintessential super mario brothers theme song.

awesome.

By: Zorink

Zorink — Sat, 14 Jun 2008 05:58:15 +0000

Sweet! I’m working on a 2 ft coil right now, so any chance of a full write up on how to make it play music?

By: Giovanni From arc attack

Giovanni From arc attack — Sat, 14 Jun 2008 00:19:36 +0000

Using monophonic coils we can get the sparks a lot bigger, but give it time :-)

By: Yann

Yann — Fri, 13 Jun 2008 19:29:07 +0000

Quick question: I always only see coils playing single notes songs. Is there a real limitation that prevents playing full wave sound, or would it require that it’s at least converted to a PMS signal first ?

By: John

John — Fri, 13 Jun 2008 18:54:43 +0000

This was at a regional Burning Man event called Flipside. Very cool to watch and listen to. Really impressive control schemes on the musical components. Ididnt get a chance to look at it during the day all the gear was put away. Was talking to the guy who thought it up. 3 Octaves worth of notes so far. They were experiment with jacobs ladders and other devices for different tunes. Absolutely brilliant

By: Jonas

Jonas — Fri, 13 Jun 2008 16:22:30 +0000

AWESOME!!!

By: bill

bill — Fri, 13 Jun 2008 15:48:01 +0000

if you’re interested in similar stuff Google “plasma tweeter”

You’ll find a number of related/similar projects.

By: samodelkin

samodelkin — Fri, 13 Jun 2008 07:34:56 +0000

Another variant – an organ made of rows of tesla coils, each of a fixed frequency. Even less practical, but should look impressive.

By: HeBD

HeBD — Fri, 13 Jun 2008 06:51:53 +0000

OMG!!!!!! the best hackaday post of over 100 this week(what happened to 7 a week?).

please for the love of god just a few words about it and the link for us to read the details. were not babies. we dont need to have the write up interpreted for us.

ONE blog per day with whatever has been found for that day. if u miss the deadline them just add it to tomorrows blog. its not like theres a low supply of hacks atm.

By: thegimpster

thegimpster — Fri, 13 Jun 2008 05:55:50 +0000

I can’t wait till the Blue Man Group get ahold of one of these. Much better than the PVC organ