Singing Tesla coils

The video above is ArcAttack! playing the classic “Popcorn” through their signature Tesla coils. Solid state Tesla coils (SSTC) can generate sound using what [Ed Ward] calls pulse repetition frequency (PRF) modulation. The heat generated by the plasma flame causes rapid expansion of the surrounding air and a resulting soundwave. An SSTC can be operated at just about any frequency, so you just need to build a controller to handle it. The task is made more difficult because very few electronics are stable in such an intense EM field. [Ed] constructed a small Faraday cage for his microcontroller and used optical interconnects to deliver the signals to the Tesla coils.

[via Laughing Squid]

Back from Vegas Extra

I made it home after a long day of travel. Airport security let me through with my new home server – a 1U dual P3 800Mhz Compaq rackmount that I scored from the guys at UNIX surplus. Yes, it was my carry-on personal item.

Somehow I missed the MIDI tesla coil last month. Thanks to [skuhl] for sending it in. It’s a solid state coil that’s modulated to create one bad-ass midi box. The videos are worth checking out.

[martin] tells me that the Pentax k10d firmware has been hacked for polish menus. I’ll let you guys sort through it, I’m honestly too tired to deal with translating it right now.

[Alex] re-cased a macbook power supply to repair a slightly ripped out power cable. Those power supplies aren’t cheap, so it’s worth noting.

By the way, I’ve got one of the midnight research wicrawl CDs, so ask nice if you want me to put up a torrent.

Tesla gone wild

I’ve gotten quite a few good submissions lately, so don’t get mad if you’re not up. I can’t resist high voltages, so this Tesla coil project capable of 30 inch lightning bolts built by [PlasmaFire] caught my eye. Not too bad for a high school project.

From his description: The Tesla Coil that I built runs on normal house current (120VAC, 60Hz), fed through line filters to two Franceformer 9060 P-E neon sign transformers that output 9000 volts at 60ma each. After going through a high-voltage Terry-style RFI filter, the power is stored in a 4.0-joule capacitor bank. This energy is dumped into a copper-coil primary. The secondary, made from cast acrylic and motor winding wire, and a topload, made from dryer duct, aluminum foil tape, and a wood disc, complete the overall assembly.

(oh, and just for fun: the cylon roomba. Thanks [tod])