Trejo 1 Noah Trejo EECE 4991 Dr. Griffin 10 September 2024 Project Proposal 1. Problem Definition The problem I have is the simple fact that I always forget to charge my phone. The danger with this is that my phone is dead often; especially in the worst situations. If my phone dies when I am out on a hike, I have no way of calling for help if I get lost. If my phone dies during a power outage and I have to access my vehicle, I will also be unable to call emergency services if needed. This is a dangerous bad habit of mine, even portable chargers are futile because I forget to charge those too. 2. Solution Concept I propose the idea of designing and creating a device that can convert mechanical power into electrical power to charge my phone. The device will take an RPM input from the use of a hand crank system and convert that into AC power. The device will then take the AC power and convert to DC power that is sustainable for a cellphone to handle and thus charge the cellphone. I want this device to be a usable size that could fit into a backpack, so that I can use it while out on the road, during a hike, or at home while the power is out. 3. LSI Module Design Trejo 2 4. Design Implementation I will create this design primarily using MATLAB’s Simulink function to create the circuit diagram. I will need a few components such as some sort of generator or motor block that can be used in reverse. This will represent the power generating mechanism as I will be manually turning this device by hand to generate the input power for the device. Because this is a low voltage device, I may only use a single-phase generator for the design process. The hand crank generator will create a sinusoidal input, which will then need to be converted to DC current by a diode based bridge rectifier. The rectifier will output short “bursts” of current through the rest of the system, therefore I will need a smoothing capacitor to produce a consistent DC output. An LED will be used to visually show that the DC current is flowing through the capacitor. Because this device needs a constant 5V output to be usable to charge a cellphone, I will incorporate a mosfet to limit the voltage and allow most of the power output to be expressed as output current. When it is time to construct the project, I plan on utilizing my amazon prime account to purchase various common components in a timely manner. A will need a basic component kit, consisting of diodes, capacitors, wires, LED’s, and resistors. There are also mini induction motors that can be purchased that may be wired in reverse to produce power. I plan on attaching all of these components to a universal PCB board. To make this device more “usable and original,” I will construct a custom case and cranking mechanism by my own design. I can produce these designs using AutoCAD and my home 3D printer to make this device look like something you would see on the shelf at the store. Testing the device will require great use of the oscilloscope and multimeter to ensure that my phone will not explode when connected and to map the linearity of the device. I will hook up the oscilloscope to the output of the mini induction motor. I can compare the RPM’s of the crank to the sinusoidal output to show the linearity between the rotation of my hand to the output power going into my cell phone. I can measure the output power by attaching the multimeter in series with the mosfet at the end of the device to read the current and possibly another multimeter to read its voltage. I will need to consistently verify that the output will always be 5V. If the relationship between input RPM’s and output power is a non-linear relationship, I can always move things into the frequency domain and try there.
