Electromagnetic Ouija Board
March 2020 - September 2020
Status: Postponed
The concept for this project is to have a Ouija board that can be controlled through a matrix of electromagnets to mimic supernatural effects. I took on this project during the pandemic and made very promising progress. Due to the overwhelming budget of creating a second revision, I decided to postpone this project until I could revisit it in the future. Although this project never came to fruition, I learned many valuable skills.
Purpose of the project
During Electricity and Magnetism, I wanted to explore my own application of electromagnetism. I believed this project would be a challenge due to the requirements of the project, including a complicated custom PCB, matrix of strong electromagnets, Bluetooth, and induction charging as final project was going to be embedded in wood.
Outcome
While working on this project, I have gained proficiency in:
PCB Design
How to use transistors
Shift registers
Bluetooth basics
Good experimentation practices
Although the project has not yet been completed due to the overwhelming costs it would take to make a second revision, I learned many new skills. After analyzing errors with the first PCB, next time I would opt to be more efficient by making each part in sections instead of one large PCB. I would also seek a commercial solution for the coils as making them was expensive and time consuming despite their effectiveness. Besides some minor drawbacks, this prototype was very successful and yielded promising results for a future second revision.
Steps
Coil and Circuit Design
The majority of this project consisted of experimenting with coil design and matrix control design. The coils were especially tricky because an increase of wire turns resulted in an increase of resistance, thus making it difficult to balance reasonable current and magnetic field strength. For controlling the matrix, shift registers were used to turn on and off transistors placed on each row and column.
Coil Manufacturing and Assembly
All of the coils were personally 3D printed, and due to the nature of the design, they all had to be wound to the correct number of turns. Therefore, I made a small machine using two stepper motors to wind each coil to the exact same length. After winding, each coil was fitted with pins that can be soldered to the PCB.
PCB Design and Manufacturing
After the circuit was tested and finalized, I created the PCB in EAGLE CAD. The primary challenge was fitting every component, including the battery, into a board-sized profile in all three dimensions. The different sections are the Bluetooth module (top left), Arduino (below Bluetooth), shift registers (the 4 ICs placed above the columns) and the battery circuit (top right). After designing the PCB, I sent the design to a manufacturer to have it produced and delivered.
Coding and Final Assembly
Although the final assembly was not completed, each module was tested and verified to work well. The Bluetooth was able to connect to any device and receive messages, and the coils were able to be controlled as desired. After testing the battery circuit, all that was left to do was manufacture all of the remaining 171 coils and enclose the project in wood. Unfortunately, the overwhelming budget of fixing minor issues made the project difficult to complete. I look forward to the project's completion.