PCB Tesla Coil Is Perfect Desk Toy

A Tesla coil easily makes it to the top spot on our list of “Mad Scientist” equipment we want for the lab, second only to maybe a Jacob’s Ladder. Even then, it’s kind of unfair advantage because you know people only want a Jacob’s Ladder for that awesome sound it makes. Sound effects not withstanding, it’s Tesla coil all the way, no question.

Unfortunately, winding your own Tesla coil is kind of a hassle. Even on relatively small builds, you’ll generally need to setup some kind of winding jig just to do the secondary coil, which can be a project in itself. So when [Daniel Eindhoven] sent his no-wind Tesla coil into the tip line, it immediately got our attention.

The genius in his design is that the coils are actually etched into the PCB, completely taking the human effort out of the equation. Made up of 6 mil traces with 6 mil separation, the PCB coil manages to pack a 25 meter long, 160 turn coil into an incredibly compact package. As you might expect, such a tiny Tesla coil isn’t exactly going to be a powerhouse, and in fact [Daniel] has managed to get the entirely thing running on the 500 mA output of your standard USB 2.0 port.

In such a low-power setup, [Daniel] was also able to replace the traditional spark gap pulse generator with a PIC18F14K50 microcontroller, further simplifying the design. An advantage of using a microcontroller for the pulse generator is that it’s very easy to adjust the coil’s operating frequency, allowing for neat tricks like making the coil “sing” by bringing its frequency into the audible range.

For those looking to build their own version, [Daniel] has put the PCB schematic and firmware available for download on his site. He also mentions that, in collaboration with Elektor magazine, he will be producing a kit in the near future. Definitely something we’ll be keeping an eye out for.

Incidentally, this isn’t the first time [Daniel] has demonstrated his mastery of high voltage. He scared impressed us all the way back in 2010 with his 11,344 Joule capacitor bank, perfect for that laptop-destroying rail gun you’ve been meaning to build.

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OneTesla Electrifies Maker Faire NY 2013

onetesla

Throughout the maker pavilion, the siren song of a musical Tesla coil could be heard. Those who followed their ears found themselves at the oneTesla booth. OneTesla is a hobby Tesla coil, with the added twist of polyphonic MIDI input.

Started by three MIT students, oneTesla had a successful Kickstarter campaign last year. Like many kickstarters, they are a bit behind in the shipping department. They are shipping out their third run of kits to backers now. The group had a small number of oneTesla coils for sale at the show, which appeared to have sold out by midday Sunday.

The actual process of generating sound with a Tesla coil is fascinating. All Tesla coils are resonant at high frequency. In oneTesla’s case, this is 220kHz. Human hearing ends around 20kHz, so this is well beyond the range of perception. Since the coil is locked in at this frequency, the power to the coil is modulated at the desired sound frequency. Playing an A note for example, would mean modulating the coil at 440Hz.

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