Bike BuddyGroup 15 Sponsored byAri Nacius

Nowook Park

Ethan Pemble

Nick Quinlan

School of Electrical Engineering & Computer Science

Motivation

Bicycle generators on the market today are used only to power headlights.

Our goal is to expand on possible applications of this alternative energy source by providing additional features to the bike rider.

Bicycle headlight

Bike Buddy

Bike Buddy uses a portable AC generator to harness power from pedaling.

This power is stored in a lithium-ion battery and is supplied to the display unit and external USB devices.

Bike Buddy attaches to the bicycle and displays riding information. Speed (mph) and direction Lat./Long. coordinates Ambient temperature Power generated by pedaling

(Watts)

[picture]

12:37 PM67 °F

Lat: 28.60265

NE6.73 MPH

Lon: -81.23185

Generating 3.7 Watts

Goals

To provide the rider’s position and direction using GPS system.

To efficiently power all systems with the AC generator while displaying accurate information to the rider.

To serve as a portable, flexible charging system that can be mounted on any bike.

Bicycle tire-mounted generator

Power Flow Diagram

AC generator

DC converter

Battery charger

6v regulator 5v regulator 3.3v regulator

LCD Temp sensor µC GPS

Battery switcher

USB

Pedal the bikePower

System

Display System

Li-Ion

Li-Ion

Power Design Review

PeripheralOperating Voltage

Maximum Current

Power Requirement

uController 3.3v 19 mA 62.7 mW

LCD 6v 220 mA 1320 mW

GPS 3.3v 70 mA 231 mW

Temp sensor 5v 1 mA 5 mW

USB port 5v 500 mA 2500 mW

Total Power

4.12 W

System Power Requirements

Generator

The generator has a rated output of 6 watts, and produces 10-20 volts AC at a comfortable riding speed.

Battery charger

This is converted to DC and charges one of two Lithium-Ion batteries in roughly 60 minutes.

Battery switcher

When the battery level is nearly depleted at 3.5 volts, it is swapped with the charged battery.

Display system

Bike Buddy can operate for approximately 70 minutes before depleting one of the batteries.

Lithium-Ion BatteryCapacity 1400 mAh

Voltage 7.4 V (8.4 V peak)

Max charge current

1 C or 1.4 A

Max current draw 0.87 A

Weight 2.5 oz

Further Applications

Additional features for Bike Buddy Exercise (tracking calories burned, heart rate)

Implement a security system

Expand GPS capabilities with a map & directions system

Support charging for more kinds of devices

Modify design for indoor use as a household power generator

Thank you!

Bike Buddy

Group 15 Sponsored byAri Nacius

Nowook Park

Ethan Pemble

Nick Quinlan