Tesla coils had some interesting applications in the early 20th century, including in sparkgap radio transmitters and electrotherapy medical devices, but they were mostly used by Nikola Tesla for experiments and demonstrations. Today, most people will recognize them as the electric arc-generating props in movies, or from a physics class. Usually they’re somewhat difficult to build, because the large coils need to be wound. But Niklas Fauth has designed a PCB-based Tesla coil that doesn’t require any coil winding.
Fauth was inspired to build this project after coming across two devices at an electronica fair in Germany. The first was a spiral Tesla coil created by Daniel Eindhoven. The second is a new series of gallium-nitride switches developed by Texas Instruments. Tesla coils work by taking a small current and using it to generate high voltages by quickly switching it through a double-tuned resonant transformer. Fauth thought Texas Instruments’ new gallium-nitride switches, which were designed for fast-switching power converters, would be perfect for making a compact Tesla coil.
The result is a small desktop Tesla coil that can be powered via a 5V 3A USB C power supply, which could just be your computer. The device is spread across three custom PCBs, which are stacked together. On top, there is a small needle, and electric arcs up to 5cm shoot off of that. When connected to a computer, the Tesla coil shows up as a standard MIDI device. That means the arcs can be controlled using any conventional MIDI software. Fauth does say that the components are difficult to solder onto the PCBs, but has released all of his design files on GitHub if you want to give it a try yourself.