Objectives
I have more than 10 years experience in electronics, however, I have never thought an electrical waveform can make someone fun. This project was done with DJ Umenos who studies nuclear fusion on his daytime. The combination of his physics-musical philosophy and my electro-mechanical skill seemed to be unique, and it is actually.
Sounds from Plasma
Among other sources of sound, like mechanics, fluidics or mathematical, we chose the plasma. Although the plasma can be found everywhere such as Neon sign and fluorescent tubes, most people have never heard the sound of it. So I designed the circuit to generate an open air spark (breakdown of the air) using the flyback capacitors scavaged from old CRT display.
While playing with this prototype, we found out that the phone pickups which is composed of induction coil and magnetic concentrator (like the picture below) could pick much clear sound than the capacitive microphone. This sound can be heard below.
Figure The phone pickup.
It is worth to mention here that the electrical noise from flyback transformer so some kind of electromagnetic shield is necessary.
Building machine
This part is most important to bring this experimental setup out of a laboratory. The machine must contain:
- Transformer and high voltage pulse generation circuit
- Low voltage regulator for gate drive circuit, cooling fan and indicator
- Current meter to protect FETs.
- EM shield for flyback transformer
- Adjustable spark gap
The completed machine is shown below. My current favorite material, plywood is used for this entire structure.
Figure 1 Completed synthesizer. Position adjustable spark gap is formed in the center. Circuit boards are visible through acrylic window to check any smoke coming out 😛
In contrast to research instruments, all knobs and switches are positioned on the top plate instead of a front panel. The box is assembled from laser-cut plywood plates. I will mention this design somewhere soon.
It’s time to live!
On Jan.30.2018, we launched this machine to the public on the local event of San Diego called “Open oscillator”. Dj Umenos’s sound effect with a minimum setup made the sound of this machine incredibly powerful. Please check the Youtube video below.
Appendix: Circuits
Please let me know that my transformer driver circuit still has the critical problem that FET sometimes toasted accidentally. Any ideas?
Figure X. Inside of the plasma synthesizer. Left above: the 180VDC generator and the transformer driver board, Right above: 12 V regulation board,Left bottom: electrical shield box for the flyback transformer.