P19463: Water Powered USB Charger
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# Preliminary Detailed Design

 Table of Contents 1 Team Vision for Preliminary Detailed Design Phase 2 Feasibility: Prototyping, Analysis, Simulation 3 Test Plans 4 Drawings, Schematics, Flow Charts, Simulations 5 Bill of Material (BOM) 6 Risk Assessment 7 Design Review Materials 8 Plans for next phase

## Team Vision for Preliminary Detailed Design Phase

Our team planned to have a better idea on the details of the design we have chosen. We planned to test motors and create a first draft of a blade design based off the values determined from motor testing. Motor testing will allow us to better calculate the dimensions of the blade design. The RPM values at different voltages are used to determine a torque value and ideal water speed value. This calculation will also help with purchasing the correct magnets that will be used as a plan A to waterproof the system.

We tested the motors at different voltages and created a plot of the corresponding RPM to voltage. The RPM was measured using a tachometer, and the voltage was the controlled input. These RPM values along with the electrical power are used to calculate the torque and theta values to help design the blades. A first version of the detailed design has been modeled. A first version anchor system has been discussed.

## Feasibility: Prototyping, Analysis, Simulation

Assumptions: Product will operate in 0.7-6.8 mph water speeds, largest radius will be 3 inches, will need to produce 7V of power for the motor to output 5V. To be able to design our product the governing equations below are available In the testing section you will see how the RPM at the needed power was measured from chosen motors. Then, the angular velocity needed for the turbine is calculated.

(1)

With this information and knowing the power that is needed the torque value is calculated from the equation below.

(2)

Calculated torque value is used for blade design attributes that can be found from the equation below

(3)

Theta is our pitch angle of the blades.

This will be the starting point in picking the correct motor and an efficient blade design. The calculations also verify if the requirement of 5V output if possible in these various water conditions.

## Test Plans

Test Set Up (1)

Test Set Up (2)

Test Set Up (3)

Test Set Up (4)

#### Procedure

1. Acquire all materials and make the disk as indicated in Figure 2.
2. Make electrical connections.
3. Measure the RPM at varied voltages starting at 5V and increasing by 1V until 15V. 15V being the last measurement.
4. Plot data collected. RPM vs. Voltage.

Test Set Up (5)

#### Results

Test Results (1)

Test Results (2)

Test Results (3)

Test Results UBEC DC_DC Efficiency (4)

Test Results LM2596 DC_DC Efficiency (5)

## Drawings, Schematics, Flow Charts, Simulations

Power Plant (1)

Power Plant Model(2)

Power Plant Generator Model(3)

Power Plant DC_Dc Buck Model(4)

#### Hydro Charge Simulation Results

Simulation Results(1)

Simulation Results(2)

#### Pacific DC Motor Model

DC Motor Block Diagram(1)

Code(4)

#### Output and Destination

DC Motor Step Response (1)

#### 3D Modeling

Section view of preliminary design(1)

Isometric View(1)

## Bill of Material (BOM)

Current List of Purchases(1)

Complied List of Expected Purchases:

• Coupling driven magnets
• Hub for the turbine
• Cord for electrical components
• Product to water proof electronics
• Offshore housing
• Anchor system

## Risk Assessment

• Updated assessment from Subsystems Design. Have you driven the likelihood and/or severity down as you worked through the details of your design?
• Include a snapshot of your current risk assessment as well as a link to the live document.

## Design Review Materials

Design Presentation

## Plans for next phase

Plans for Next Phase