Home-Securtiy Light-emitting diodes are one of the wonders of electronics. They have been around as semiconductors since the 60s and have been used for all sorts of electronic applications; from car alarms, camera active warning lights to indication of working circuits on mainframe computers. Nowadays the display monitors in airports and in electronic billboards are using LED backlights instead of the not really very old Liquid Crystal display (LCD) These LED Screens offer finer resolution. In recent years the output and development of LEDs has increased in brightness and color range so it is no wonder that police and other emergency vehicles are standardizing on The LED Lightbar as the best solution for warning lights. The LED Lightbar on emergency vehicles are those robust, multi-colored sets of lights that are often roof mounted. With the modern increase in luminescence and the durability and reliability of the modern LED the advantages are that they can be switched on at a moment’s notice and are instantly noticeable. If one is driving in traffic and a blue flashing LED lightbar on an emergency vehicle is behind you, you know it is a police vehicle on an urgent mission and it is best to get out of the way. The life of an LED is in the region of 25,000 hours and upwards provided they are not subject to excessive current and heat. A further advantage of the LED technology is the increased efficiency. LEDs use far less current for a similar candlepower output that do incandescent lights. Incandescent lights generate heat as the filament lights up with the resistance to current. It is the heat which uses up the current. LEDs do not get hot so there is no loss of current from unwanted waste. (Another big advantage is that LEDs are clearly visible in the daytime. The old rotating beacons have largely been replaced by The LED Lightbar . They use clear and colorless domes as the LED itself is the source of the color. And because of the electronics involved and very rapid on/off capabilities all sorts of patterns may be programmed. The old strobe beacons were typically just one color. Blue meant Police, Red was fire or ambulance and yellow was for services (street sweepers, road crews, garbage trucks). These are still pretty much the case now. Blue lights, sometimes combined with Red flashing on The LED Lightbar are almost exclusively Law enforcement, whether police or traffic control. If one comes across a whole lot of blue flashing lights at the side of the road, be it in daylight or after dark it behooves one to slow down and exercise caution as it almost certainly is a police action ahead. Many a Police LED lightbar has a programmable message board that can either be a static or rolling message. These can be programmed for a stock of standard messages or typed in by the officer at the scene. Typical of these messages would be "Slow Down, Accident ahead" or "Stop, Police roadblock" A red LED lightbar is for an emergency vehicle in all states of the USA. There are minor additions in Iowa, Wisconsin and Washington State. An Amber or yellow LED lightbar still means construction vehicles or similar services. Usually no one has to give way to amber light but caution must be exercised as the speed is likely to be slow and there may be attendants on foot moving about on the roadway. The LED Lightbar is a major step forward in the equipping of the modern emergency vehicle. About the Author: 相关的主题文章: