DESIGN, OPERATION, AND UTILIZATION OF CHANGEABLE-MESSAGE SIGNS WITH EMPHASIS ON THE ROTATING-DRUM TYPE
ALTHOUGH TABLES ARE PRESENTED ON THE FUNCTIONS AND TYPES OF VARIABLE MESSAGE SIGNS AVAILABLE, THE ROTARY DRUM TYPE IS SINGLED OUT FOR SPECIAL ATTENTION. BASICALLY, IT IS DESCRIBED AS A TRIANGULAR-SHAPED DRUM PIVOTED ON EACH END, MOUNTED WITHIN AN ENCLOSURE WITH ROTORS ATTACHED TO EACH FACE BEARING THE MESSAGE SIGN. HEATING COILS LOCATED IN THE PERIPHERY OF THE DRUM OPENING PREVENT ICE FORMATION: A 12-V DC MOTOR IS PROVIDED IN THE EVENT OF POWER FAILURE: MANUAL ROTATION OF THE ROTORS IS A BUILT-IN FEATURE. SIMPLE RELAYS, TIMERS, THERMOSTATS, CAPACITOR MOTORS, AND MICROSWITCHES ARE COMBINED IN A STRAIGHT-LINE HARDWIRE CIRCUITRY. TWO TYPES OF REMOTE CONTROL SYSTEMS ARE DESCRIBED: (1) AN UNDERGROUND HARD-WIRE CABLING SYSTEM FOR CONTROL UP TO 5 MILES, AND (2) A TIME-SHARING OF A 2-WIRE COMMUNICATION CIRCUIT FOR SIGNS OVER LONG DISTANCES.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309020530
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Supplemental Notes:
- Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
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Corporate Authors:
Highway Research Board
2101 Constitution Avenue, NW
Washington, DC 20418 -
Authors:
- Dunne, Samuel B
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Conference:
- Conference on the Changeable-Message Concept of Traffic Control
- Date: 1971-7-15 to 1971-7-16
- Publication Date: 1972
Media Info
- Media Type: Digital/other
- Features: Tables;
- Pagination: p. 33-36
- Monograph Title: THE CHANGEABLE-MESSAGE CONCEPT OF TRAFFIC CONTROL
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Serial:
- Highway Research Board Special Report
- Issue Number: 129
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Coils (Electromagnetism); Design; Direct current motors; Electric circuits; Remote control; Tables (Data); Variable message signs
- Old TRIS Terms: Circuits; Remote control systems
- Subject Areas: Design; Highways; Operations and Traffic Management;
Filing Info
- Accession Number: 00226393
- Record Type: Publication
- ISBN: 0309020530
- Files: TRIS, TRB, ATRI
- Created Date: Feb 3 1973 12:00AM