Published April 3, 2021 © GPL3+

DIY Arduino Audio modulated (misical) Tesla Coil

This Tesla Coil has been modified so that the spark "sings" melody generated by a sound source.

IntermediateFull instructions provided5 hours6,007

DIY Arduino Audio modulated (misical) Tesla Coil

Things used in this project

Hardware components

Arduino Nano R3

Power MOSFET N-Channel

Rotary potentiometer (generic)

Capacitor 10 µF

capacitor 330 nF

Resistor 330 ohm

GU81 Tesla Coil

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Story

A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity.

In one of the previous videos I described the making of a Tesla Coil with Russian Vacuum tube GU81. This time this Tesla Coil has been modified so that the spark "sings" melody generated by a sound source.

Modulator circuit consist of one Power Mosfet and Arduino Microcontroller. The principle of operation is simple: Power tube oscillator, generating high frequency high voltage, is amplitude modulated. Changes in the intensity of the discharge is heard as sound. Thus, if oscillator is modulated by the audio signal, The discharge or plasma flame actc as a speaker.

Modulation is introduced to the cathode using MOSFET Transistor. In this case it is IRF740, but any Power mosfet can be used. It is only important that it be mounted on a large enough aluminum cooler.

The source of the audio signal in this case is the Arduino nano microcontroller. For this purpose, a simple codes are presented that generates a certain melody at output 9 of the microcontroller. This signal is now fed to the input of the modulator and next to the Cathode of the Vacuum Tube.

And at the end, If you decide to make this project, do not forget to watch my video where the construction of GU81 Tesla coil is described in detail, which is the basis for making this "Spark speaker":

Let me remind you that this circuit is a very dangerous one. The output voltage of this circuit is in Kilo volts and it can seriously injure you or kill you. Try this circuit only if you have enough experience dealing with high voltages. I have no responsibility on any hazards caused by the circuit. Be very careful. This is a humble request.

Code

const int c = 261;
const int d = 294;
const int e = 329;
const int f = 349;
const int g = 391;
const int gS = 415;
const int a = 440;
const int aS = 455;
const int b = 466;
const int cH = 523;
const int cSH = 554;
const int dH = 587;
const int dSH = 622;
const int eH = 659;
const int fH = 698;
const int fSH = 740;
const int gH = 784;
const int gSH = 830;
const int aH = 880;
 
const int buzzerPin = 9; // Digital Pin 9
const int ledPin1 = 4;  // Digital Pin 4
const int ledPin2 = 6;  // Digital Pin 6 Built In Led can Change it if you want
 
int counter = 0; 
 
void setup()
{
  //Setup pin modes
  pinMode(buzzerPin, OUTPUT); // Digital Pin 9
  pinMode(ledPin1, OUTPUT);  // Digital Pin 4
  pinMode(ledPin2, OUTPUT); // Digital Pin 6 Built In Led can Change it if you want
}
 
void loop()
{
 
  //Play first section
  firstSection();
 
  //Play second section
  secondSection();
 
  //Variant 1
  beep(f, 250);  
  beep(gS, 500);  
  beep(f, 350);  
  beep(a, 125);
  beep(cH, 500);
  beep(a, 375);  
  beep(cH, 125);
  beep(eH, 650);
 
  delay(500);
 
  //Repeat second section
  secondSection();
 
  //Variant 2
  beep(f, 250);  
  beep(gS, 500);  
  beep(f, 375);  
  beep(cH, 125);
  beep(a, 500);  
  beep(f, 375);  
  beep(cH, 125);
  beep(a, 650);  
 
  delay(650);
}
 
void beep(int note, int duration)
{
  //Play tone on buzzerPin
  tone(buzzerPin, note, duration);
 
  //Play different LED depending on value of 'counter'
  if(counter % 2 == 0)
  {
    digitalWrite(ledPin1, HIGH);
    delay(duration);
    digitalWrite(ledPin1, LOW);
  }else
  {
    digitalWrite(ledPin2, HIGH);
    delay(duration);
    digitalWrite(ledPin2, LOW);
  }
 
  //Stop tone on buzzerPin
  noTone(buzzerPin);
 
  delay(50);
 
  //Increment counter
  counter++;
}
 
void firstSection()
{
  beep(a, 500);
  beep(a, 500);    
  beep(a, 500);
  beep(f, 350);
  beep(cH, 150);  
  beep(a, 500);
  beep(f, 350);
  beep(cH, 150);
  beep(a, 650);
 
  delay(500);
 
  beep(eH, 500);
  beep(eH, 500);
  beep(eH, 500);  
  beep(fH, 350);
  beep(cH, 150);
  beep(gS, 500);
  beep(f, 350);
  beep(cH, 150);
  beep(a, 650);
 
  delay(500);
}
 
void secondSection()
{
  beep(aH, 500);
  beep(a, 300);
  beep(a, 150);
  beep(aH, 500);
  beep(gSH, 325);
  beep(gH, 175);
  beep(fSH, 125);
  beep(fH, 125);    
  beep(fSH, 250);
 
  delay(325);
 
  beep(aS, 250);
  beep(dSH, 500);
  beep(dH, 325);  
  beep(cSH, 175);  
  beep(cH, 125);  
  beep(b, 125);  
  beep(cH, 250);  
 
  delay(350);
}

int speakerPin = 9;

int length = 28; // the number of notes

char notes[] = "GGAGcB GGAGdc GGxecBA yyecdc";

int beats[] = { 2, 2, 8, 8, 8, 16, 1, 2, 2, 8, 8,8, 16, 1, 2,2,8,8,8,8,16, 1,2,2,8,8,8,16 };

int tempo = 150;

void playTone(int tone, int duration) {

for (long i = 0; i < duration * 1000L; i += tone * 2) {

   digitalWrite(speakerPin, HIGH);

   delayMicroseconds(tone);

   digitalWrite(speakerPin, LOW);

   delayMicroseconds(tone);

}

}

void playNote(char note, int duration) {

char names[] = {'C', 'D', 'E', 'F', 'G', 'A', 'B',           

                 'c', 'd', 'e', 'f', 'g', 'a', 'b',

                 'x', 'y' };

int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014,

                 956,  834,  765,  593,  468,  346,  224,

                 655 , 715 };

int SPEE = 5;

// play the tone corresponding to the note name

for (int i = 0; i < 17; i++) {

   if (names[i] == note) {
    int newduration = duration/SPEE;
     playTone(tones[i], newduration);

   }

}

}

void setup() {

pinMode(speakerPin, OUTPUT);

}

void loop() {

for (int i = 0; i < length; i++) {

   if (notes[i] == ' ') {

     delay(beats[i] * tempo); // rest

   } else {

     playNote(notes[i], beats[i] * tempo);

   }

   // pause between notes

   delay(tempo);

}

}

int speakerPin = 9;
int length = 26;
char notes[] = "eeeeeeegcde fffffeeeeddedg";
int beats[] = { 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2};

int tempo = 300;
void playTone(int tone, int duration) {
  for (long i = 0; i < duration * 1000L; i += tone * 2) {
    digitalWrite(speakerPin, HIGH);
    delayMicroseconds(tone);
    digitalWrite(speakerPin, LOW);
    delayMicroseconds(tone);
  }
}
void playNote(char note, int duration) {
  char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
  int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014, 956 };
  
  // play the tone corresponding to the note name
  for (int i = 0; i < 8; i++) {
    if (names[i] == note) {
      playTone(tones[i], duration);
    }
  }
}
void setup() {
  pinMode(speakerPin, OUTPUT);
}
void loop() {
  for (int i = 0; i < length; i++) {
    if (notes[i] == ' ') {
      delay(beats[i] * tempo); // rest
    } else {
      playNote(notes[i], beats[i] * tempo);
    }
    
    // pause between notes
    delay(tempo / 2); 

    }

  }

DIY Arduino Audio modulated (misical) Tesla Coil

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

Arduino Part

Modulator

Dimmer

Tesla Coil

Code

Code( Imperial March Theme)

Code(Happy Birdhday Theme)

Code(Jingle Bells Theme)

Credits

Mirko Pavleski

Comments

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DIY Arduino Audio modulated (misical) Tesla Coil

DIY Arduino Audio modulated (misical) Tesla Coil

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

Arduino Part

Modulator

Dimmer

Tesla Coil

Code

Code( Imperial March Theme)

Code(Happy Birdhday Theme)

Code(Jingle Bells Theme)

Credits

Mirko Pavleski

Comments

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