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The Tesla Coils' Mystery
Grupa: FILS 1221EA
Introduction
The purpose is to apply the knowledge gathered in the laboratory. To demonstrate the phenomenon, the Tesla coil circuit will generate an electric arc with a high voltage and a high frequency of the electromagnetic field that displays the phenomenon's bolt of artificial lightning. This electric discharge will also be modified to produce musical tones by modulating its spark output via an arduino interface. Optionally, I will redo some experiments to demonstrate alternative methods of highlighting the coil's high-frequency electromagnetic field such as (lighting an incandescent light bulb without any direct electrical connection), also using the arduino interface.
The basic phenomena is the Tesla coil effect, and it uses this phenomenon to replicate sound frequencies. Tesla Coil is an electrical Resonant Transformer Circuit that generates exceptional levels of voltage and sparks, as well as the capacity to destroy or switch on electronics from a distance. To resonate, tune, and adjust the voltage, the Tesla coil uses capacitors, spark gaps, and multiple coils.
General Description
The following block diagram corresponds to the project:
First case:
Second case:
The project will be put together as follows:
The data storage module communicates with the Arduino via both the Lab 5 (SPI) and Lab 1 (UART) interfaces in this setup. Internal connection between the module and the microcontroller is enabled by SPI, whereas bidirectional communication between the Arduino and the module is enabled through UART. This enables efficient file storing and retrieval of musical notes.
For the second case, the microSD card in the DFMini Player Mp3 module is used to store and play mp3 music. Through UART, the Arduino interfaces with the DFMini MP3 Player module, allowing for control and data exchange. Furthermore, the module uses SPI internally to communicate with the microSD card. The DFRobotDFPlayerMini library, which provides a higher-level interface for smooth interaction with the module and microSD card, is used for this internal SPI connection.
The Tesla coil's excitation module (circuit) will interpret the notes as signals of various frequency. The secondary coil will generate them in the auditory spectrum using a very high voltage electric arc. Optionally, based on the servo motor and a light bulb, I propose implementing PMW (L3) to emphasize the existence of the secondary coil's high frequency and high voltage electromagnetic field.
Hardware Design
| Component | Quantity |
|---|---|
| Arduino Uno R3 | x1 |
| Arduino Nano | x1 |
| DFPlayer - A Mini MP3 Player | x1 |
| Fan | x1 |
| BD243C High Power NPN 100V | x1 |
| 80NF70 N-channel 68V Power MOSFET | x1 |
| Transistor Heat Sinks | x2 |
| 10µF 50V electrolytic capacitor | x1 |
| 1µF 105J 100V polyester capacitor | x1 |
| 4N35 Optocoupler | x1 |
| 2kΩ Resistors | x2 |
| 10kΩ Resistors | x2 |
| 220Ω Resistor | x1 |
| 330Ω Resistor | x1 |
| LED red | x1 |
| LED blue | x1 |
| pre-wound coil | x1 |
| stereo audio socket | x1 |
| power jack | x1 |
| 3.5mm stereo audio cable | x1 |
| Dupont Jumper Wires | x30 |
| wire | 15cm |
| strip double-sided tape | 5cm |
| screws | x6 |
| brass standoffs | x4 |
| Power Supply 9V for Arduino | x1 |
| Power Supply 15-24V for Tesla Coil | x1 |
| Universal PCB board | x1 |
| Servo motor | x1 |
| Micro- SD Card Memory Module | x1 |
| Soldering iron | x1 |
| Led/Bulb | x1 |
| USB Cable for Arduino Uno | x1 |
| USB Cable for Arduino Nano | x1 |
| passive buzzer (optional) | x1 |
| Micro SDHC card 32GB | x1 |
Digital Input Signal
Analog Input Signal
This project's circuit is a modified version of the “slayer exciter,” a sort of Tesla transformer notable for its self-governing oscillation. The slayer exciter circuit, unlike classic Tesla coils, uses feedback from the secondary coil to enable self-tuning and self-resonating operation, avoiding the need for complex circuitry.
Some creative additions have been made to this version of the circuit. The current to the coil is modulated by an audio input via the 80NF70 NFET (Q2), while one LED (D2) is modulated by the audio input and another LED (D1) is modulated by the coil's oscillations. The audio-modulated coil can vibrate, and the plastic tube that acts as the coil's core resonates, effectively functioning as a speaker.
The “slayer exciter” self-governing oscillation is crucial to the circuit's operation.
Basic explanation of how it works with a single transistor:
- The circuit is initially powered on, and the transistor (Q1) is in the “on” position. This means that current can pass through the Tesla coil's primary coil.
- A magnetic field forms around the primary coil when current travels through it. This magnetic field causes a voltage to be generated in the secondary coil, which is wrapped around the primary coil.
- However, an unusual event occurs when the current in the secondary coil exceeds a particular threshold, often the breakdown current of an LED linked in series.The transistor's base is linked to ground, thus pulling it “down” and causing the transistor to reach a cutoff state.
- When the transistor reaches cutoff mode, current is no longer conducted through the primary coil. This causes the magnetic field generated by the primary coil to collapse.
- A high-voltage flyback voltage is induced in the primary coil as the magnetic field decreases. This flyback voltage discharges into the surrounding air, causing an electric arc or plasma to form.
- The interruption of current flow in the primary coil has an effect on the secondary coil as well. A voltage spike in the secondary coil is caused by the sudden shift in magnetic field, which might result in a high-voltage output.
- The process is repeated indefinitely. When the flyback voltage dissipates and the current in the secondary coil falls below the breakdown level of the LED connected in series, the voltage falls below the breakdown level of the LED. This permits the transistor to return to saturation mode, turning it “on” and commencing the magnetic field accumulation.
The slayer exciter circuit can be controlled by modulating the circuit on and off with an interrupter, such as an Arduino combined with an optocoupler. This modulation can be done at the frequency of a certain musical note, and the ensuing electric arcs created by the Tesla coil can produce audible sounds at the modulated frequency.
Software Design
To interface the Musical Tesla Coil Slayer exciter circuit, which can accept analog or digital input signals, I conducted experiments to determine how the circuit can receive the signal and implemented the code accordingly. When an analog input is received, the circuit plays melodies, while digital input triggers the playback of musical notes.
I developed the programs using the Arduino IDE and included additional libraries and 3rd-party sources
For Analog input:
- SoftwareSerial.h
- DFRobotDFPlayerMini.h
- Servo.h
In the program, I utilized functions from these libraries to control the DFMini Player and servo motor. The DFMini Player receives commands via serial communication, with pins 10 and 11 serving as RX and TX. Melodies in integer-numbered files (e.g., 1.mp3, 2.mp3, etc.) should be stored on the memory card before specifying the commands.
Here is a summary of the program flow:
- void setup():
- Initialized communication with the module and microSD card, as well as the Arduino serial communication.
- Set initial volume control, range control, equalization commands, and other features.
- Attached the servo object to pin 3.
- void loop():
- Called the danceServo() function.
- Transmitted commands via serial communication to manage the DFPlayerMini.
- void menu_opcoes():
- An interactive menu to select the command to be sent via serial communication.
- void danceServo():
- This function accepts a pattern as input and controls the servo motor. Each pattern defines a sequence of servo positions and delays between them.
For Digital input:
- SPI.h
- SD.h
- Servo.h
- Arduino-songs Library by RobsonCouto
I developed two programs to accommodate to this scenario:
In the first program, communication with the microSD card module was established in SPI mode. A file was created to store musical notes, specifying their frequency and duration.
- The necessary Arduino pin for the SD card module's Chip Select (CS) pin was defined, and an object was created to handle file operations.
- The total number of notes was also calculated
- void setup():
- Started serial communication and plugged in the microSD card.
- On the card, I created a “note.txt” file.
- Iterated through the musical notes array, writing to the file the total number of notes, frequency, and duration.
- Closed the file
The main objective of the second program is to play the musical notes read from the microSD card. I achieved this by utilizing a buzzer (for verification) and specifically through the Tesla coil.
- I defined pins for the servo motor, SD card module, and the buzzer/digital signal. Additionally, I created an object to handle file operations.
- void setup():
- Serial communication was initialized and connected to the microSD card and servo motor.
- The file was opened to retrieve the total number of notes, frequency, and duration.
- Frequency and duration values were stored in the note[maxNotes][2] matrix.
- Closing the file, the matrix was iterated to calculate the note durations.
- The corresponding sound was generated using the tone(), delay(), and noTone() functions.
- void loop():
- Called the danceServo() function.
The danceServo() function serves the same purpose as it does for the analog signal.
Rezultate Obţinute
Furthermore, I encountered some inconvenience when transmitting melodies from the MP3 player module to the circuit via the audio jack cable. Occasionally, the connection between the audio jack plug and the stereo audio socket is unreliable, causing interruptions in the audio playback.
Concluzii
The Tesla Coil project proved to be an incredibly enjoyable and rewarding experience for me. It provided a valuable opportunity to gain practical knowledge while exploring into the fascinating realm of electrical engineering and automation. By incorporating various technical concepts and utilizing Arduino, I was able to explore a wide range of subjects that I had learned.
The project was undoubtedly laborious and provided many challenges along the way. I had to adjust and work with the resources that were available. Despite obstacles, it was a rewarding accomplishment. Through rigorous research, careful component selection, system assembly, and code development, the long endeavor provided a deep understanding of both hardware design and software development, relying on the application of electrical and software engineering skills.
This comprehensive set of abilities gained from the project provided a solid foundation for my introduction into the realm of Arduino and the broader sphere of technology. I am grateful for the experience and knowledge that not only provided me joy but also broadened my horizons in this exciting field.
Download
Arduino_NANO_TESLA_COIL_MUSICAL_ANALOG-SIGNAL -Source Code sapcaliu_maria-viorica_1221ea_teslacoil.txt
Arduino_UNO_R3_INIT_SD-CARD_DIGITAL-SIGNAL -Source Code sapcaliu_maria-viorica_1221ea_teslacoil1.1.txt
Arduino_UNO_R3_TESLA_COIL_MUSICAL_DIGITAL-SIGNAL -Source Code sapcaliu_maria-viorica_1221ea_teslacoil1.2.txt
Jurnal
Bibliografie/Resurse
Components
Arduino
