DIY HF SSTC Plasma Tweeter

This time I will describe how to make the Plasma Speaker with the help of semiconductors, specifically high power Mosfet transistors.

This design has several advantages over the same device made with vacuum tubes: Vacuum tubes are difficult to obtain nowadays and Mosfet transistors are widespread and their price is very low. Then this device works with a low voltage of less than 40 volts as opposed to the one with tubes that worked with voltages from 300 to 600 volts. Also tunning the device, in this case, is much simpler, with the help of a variable capacitor.

In fact, this is a High-Frequency Solid State Tesla coil, which is amplitude modulated. Amplitude modulation can be implemented by grafting the simple circuit between the Mosfet source and GND.

The device consists of several components:

- The output coil consisting of 150 windings of copper insulated wire with a diameter of 0.6 mm, wound on a body with a diameter of 2.5 cm.

- Oscillator coil contains 7 windings of insulated copper wire with a diameter of 2 mm which is wound on a body with a diameter of 5 cm. This coil together with the variable capacitor defines the oscillation frequency which in this case is set to 10Mhz because it is the resonant frequency of the output coil.

- Small choke coil wound on a body with a diameter of 1.5 cm and contains about 50 turns of lacquered copper wire with a diameter of 0.5 mm.

- The variable capacitor, taken from an old mid-wave radio, serves to fine-tune the oscillator circuit at the desired frequency.

- Potentiometer changes the degree of modulation of the input audio signal.

Finally, I would like to mention that the transistors should be mounted on a relatively large aluminum cooler.

DISCLAIMER! High voltages are present in this device, strong electromagnetic fields are emitted during operation. The device should NEVER be run without proper shielding. I refuse to take ANY responsibility for any possible injuries, legal problems, property damage or deaths, anything you find here is provided WITHOUT ANY WARRANTY, you do everything AT YOUR OWN RISK!