May06-06 Traffic Signs Outlined by Solar-Powered LEDs
Team Members Alexander Beecher Jason Chose James Kopaska Matthew Treska
Definitions DOT - Department of Transportation PV – Photo Voltaic (refers to solar panels) NiMH – Nickel Metal Hydride (type of battery) Pb-SN – Lead-Tin (type of battery) NiCd – Nickel Cadmium (type of battery) NEMA – National Electric Manufacturers Association (provides a forum for electrical equipment standardization)
Project Description
-Purpose of the signs are to raise driver awareness in potentially hazardous traffic areas -Signs are self-sustainable, meaning they operate with minimal operator maintenance 24/7 -The stop sign is continually operating, dimming in low light in order to allow for maximum battery efficiency and limiting distractions to drivers -The school crossing sign operates only during times of activity, determined by the user -The chevron sign only operates in low light conditions
Project Description -LEDs will not effect shape of the sign, thus eliminating confusion to drivers -Signs are constructed to handle various weather conditions -Signs have anti-vandalism features, such as locks over battery and circuit casings -An Excel spreadsheet gives criteria to the user so signs can be constructed for any locale within the continental U.S. -Signs follow federal traffic regulations, including LED flashing no more than 60 times/min and no less than 50 times/min
Technical Specifications -System operates from a 12V NiMH battery -Signs utilize either 55.5 Candela or Candela LEDs -System charges from a 14.2V solar panel -Software interface based on Microsoft Excel
Component Description PV CHARGE CONTROLLER -Prevents over current and over voltage damage to PV panel, battery, and circuit -Handles battery charging and power distribution to circuitry
Component Description LED CLUSTER -LED selection based on operational requirements Cd cluster used on night use only signs Cd cluster used on 24 hour operation signs -Color specific for each sign
Component Description FLASHER DIMMER MODULE -Ensures flashing rate between 50 and 60 times per minute -Integrated photoresistor allows automatic dimming of LEDs to match ambient light levels
Component Description FLASHER MODULE -Used on chevron sign in lieu of flasher/dimmer module -Maintains flashing rate between 50 and 60 times/min
Component Description TIMER MODULE -Used on school crosswalk sign -Allows user defined hours of operation
Component Description PHOTOVOLTAIC PANEL -Utilized on all signs -Operates at 14.2V to provide sufficient energy for 12V system
Component Description NiMH BATTERY -Operates at 12V and 1.5A -Suitable for use throughout continental U.S.
Stop Sign Specifications -Continuous operation 24 hours a day, 7 days a week -8 LED 1120mA -Automatically dims with changing ambient light
Stop Sign Specifications
School Crossing Specifications -Operates 6 hours a day, 5 days a week -5 LED 700mA -User programmable for varying school schedules
School Crossing Specifications
Chevron Specifications -Operates in low or no light conditions, 7 days a week -4 LED 360mA -LEDs located on 4 corners
Chevron Specifications
Circuit Demands Stop Sign 8 LED 1120mA Drive circuitry to operate 3.17mA Charge controller operating 30mA TOTAL: mA
Circuit Demands School Crossing Sign 5 LED 700mA Drive circuitry to operate 3.17mA Charge controller operating 30mA Timer module operating 350mA TOTAL: mA
Circuit Demands Chevron Sign 4 LED 360mA Drive circuitry to operate flasher 3.17mA Charge controller operating 30mA TOTAL: mA
Planned Construction
CONSTRUCTION COMPONENTS -Telespar tubular post -(8) BA15 LED sockets -18 AWG wire for circuitry -1/2” PVC conduit for wire raceway -1/2” PVC TB junction -Screws and other fastening tools -36” DOT stop sign -12 AWG wire for PV panel -NEMA 3R enclosure -1/2” PVC conduit straps for post mounting -NEMA 3R junction box for back of sign -Silicone calking
Software -Based on Microsoft Excel -User defines the type of sign desired, geographic location of the sign, estimated hours of day usage, estimated hours of night usage, and desired number of days sign can operate without sunlight -Calculations based on information gathered from the National Renewable Energy Laboratory
Software Screen shot for use in Birmingham, AL
Questions??