Fast and precise electromagnet driver for levitation in power storage and space launch applications

Carlton Cort, Jason Dyke

Overview

Magnetically deflected ballistic mass (MBDM) describes a system in which a metal rotor, the mass in the system, is suspended (like a maglev train) inside of an evacuated sheath. The metal rotor is sped up by linear induction motors. Because the rotor is in a nearly frictionless environment, inertia allows storage of energy in the movement of the rotor with minimal energy losses over time. This project is designed to take the first step towards MDBM technology by designing and testing an electronic control system for electromagnets that will be used to levitate a ferromagnetic object. A mild-carbon steel caster ball was selected to be the ferromagnetic object for the system. The electronics that were used to control the electromagnet were an Arduino UNO, L298N motor driver, 24V DC power supply, and two 24V DC Electromagnets. The Arduino UNO and L298N output a maximum 2A and 22V, which is greater than the electromagnets current draw, 0.1875A at a voltage less than the electromagnets’, 24V. Figure 7 shows a circuit diagram for the electronics. This control system is able to power the electromagnets at 256 different steps using PWM, allowing for precise control of the electromagnets' power at speeds much faster than can be manually achieved. During testing, it was found that at full power it takes 88.25ms on average for the top electromagnet to lift the caster ball, and the inverse exponential function is the best mathematical function for gradual correction.

Video

From the student

These are a set of slides describing my project with more detail. Some additional images of my testing setup (like the one used in my project board thumbnail) are in the additional information. There is also a picture of the finished control system which was the extension of this project that I completed in 2022.

From the student

These are just some of the pictures from the rest of my project board (and one of my senior year continuation fo the project not anywhere else) uploaded on their own so they can be seen clearly.

The first is the actual built electromagnet driver test rig.

The second is the circuit diagram of the electromagnet driver set up for testing (only one electromagnet shown).

The third is the picture of the electromagnet driver test setup that is in the thumbnail for my whole project board (and partially cut off) but not elsewhere.

The final picture is of my finished full control system test setup. This is not part of my AJAS project, but the continuation I completed over the summer and beginning of my senior year.