Transcript ECE 4884 : Senior Design

LightSaVers
Satya Bhan
Andrew Ausley
Michael Moseley
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Modules
Project
Overview
Schematic
• Lighting
• Stepper &
Sensors
Design
Decisions
&
Tradeoffs
Testing
&
Demo
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Automated light balancing via remote
blinds and dimmers
Centralized, low-power wireless network
Low bandwidth information feed via remote
sensor network
LED-based light fixture
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Low-power, LED based lighting to reduce
energy costs
Brightness comparable to 100W light bulb
Automated dimming using a microcontroller
AC-to-DC power supply removes the need
for batteries
Medium Edison adapter allows the wireless
LED light to connect to standard light socket
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Power Line Interface: Pig Nose adapter
Power Supply:120VAC-12VDC transformer
12VDC stepdown: Resistors and zener diodes
Power LEDs: 9 Luxeon Rebel I (lambertian)
LED topography: 3 branches of 3 diodes each
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The Pig Nose adapter provides superior
interchangeability
The transformer is an easy implementation
but not efficient and is expensive and bulky
The diode based stepdown circuit is quick
and easy but it draws a set amount of current
continuously reducing efficiency
The LEDs are a matter of preference
The topography depends on the DC voltage,
desired light output, desired robustness
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Remote stepper motor for blinds modulation
Interfaced with microcontroller via 4 MOSFETs
Connected to window light sensor
5VDC transformer
power supply
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Operates at 800mA
Requires 5VDC
Steps based on applied voltages to control
transistors
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Stepper motor: Power/torque
Transistors: Voltage/current rating
Power supply: transformer vs. transformerless
ZigBee: One vs. Two modules
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Rapidity of the design process led to budget
overages
Necessity of reliable, easily implemented
power step-down led to loss of efficiency
Time constraints and part availability led to
implementation of expensive microcontrollers
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The drivers, the power supply, and the
stepdown circuits should be implemented in a
single compact semiconductor chip
A simple stepper motor mount should be
designed
The system should be designed on the
minimum possible microcontroller
A custom heat sink should be designed
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Cover sensors and simulate the flowchart
System will not be run for a long period of
time due to robustness issues
Blinds may be operated manually pending
mechanical mounting of the stepper
The power savings will be tested by
measuring the current flowing to the light
fixture vs. that of an incandescent light bulb
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The system will be implemented in the Aware
Home on 10th St.
The flowchart simulation will be
demonstrated as well as the measurement
techniques for measuring the current
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