Transcript Bike Buddy - Department of Electrical Engineering and Computer

Bike Buddy
Group 15
Sponsored by
Ari 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 lithiumion battery and is supplied to the
display unit and external USB
devices.
 Bike Buddy attaches to the bicycle
and displays riding information.


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
Speed (mph) and direction
Lat./Long. coordinates
Ambient temperature
Power generated by pedaling
(Watts)
Lat: 28.60265
Lon: -81.23185
NE
6.73 MPH
12:37 PM
67 °F
Generating
3.7 Watts
[picture]
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.
Bicycle tire-mounted generator
 To serve as a portable, flexible
charging system that can be
mounted on any bike.
Power Flow Diagram
Power
System
Pedal the bike
AC generator
DC converter
Battery charger
Battery switcher
LiIon
6v regulator
Display
System
LCD
LiIon
5v regulator
Temp sensor
3.3v regulator
USB
µC
GPS
Power Design Review
Generator

Lithium-Ion Battery
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.
Capacity
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
System Power Requirements
Peripheral
Operating
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
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
Bike Buddy
Thank you!
Group 15
Ari Nacius
Nowook Park
Ethan Pemble
Nick Quinlan
Sponsored by