lightsavers satya bhan andrew ausley michael moseley 1

LightSaVers

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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

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

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