21-10-2009, 02:32 PM
[attachment=110]
check http://scribddoc/13141303/LED-Wireless for full presentation
A light-emitting diode (LED) is an electronic light source. LEDs are based on the semiconductor diode. LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching
LEDs IN Traffic light
The new traffic lights you are seeing are made out of arrays of light emitting diodes (LEDs). These are tiny, purely electronic lights that are extremely energy efficient and have a very long life
TRADITIONAL HALOGEN BULBS V/S LEDs HALOGEN BULBSLEDs
Max. lamp lifetime six months Big brightness loss after only 5000 hours Not uniform brightness Long distance visualization problems
Max. LED lifetime 10 years Brightness loss after 10,000 hours between 6% to 12% Uniform brightness Long distance better view
TRADITIONAL HALOGEN BULBS V/S LEDs CONTD¦ HALOGEN BULBS
LEDs
Delay of the bulb in the on/off Yearly interior and exterior cleaning of the Lamp
On/off cycle delay is negligible No interior cleaning is necessary
ADVANTAGES
High-speed operation are available at low cost. FCC licenses are not necessary Penetrate through glasses, but not through walls LED light beams follow a straight-line path and are well suited for the wireless delivery of large quantities of voice and data information High directional features of LEDs
DISADVANTAGES
Suitable for short range only Intensity modulation with direct detection seems the only practical transmission method. As a communication medium, it has limited range. It is subjected to noise arising from sunlight, incandescent lighting,and fluorescent lighting.
APPLICATIONS
IN TRAFFIC LIGHT IN TRAFFIC INFORMATION SYSTEM IN MUSEUM
IN TRAFFIC LIGHT
Low power consumption and minimal required maintenance. Safety Long term warranty
IN TRAFFIC NFORMATION SYSTEM
Traffic light can be used as an audio broadcasting device. A receiver some distance away pointing at the traffic light can receive voice messages. The message can announce the time until the next signal change. Voice message can tell the location or directional information.
IN MUSEUM
Information be broadcast via a plurality of LEDs. One can listen to the audio message about the specific exhibit item
check http://scribddoc/13141303/LED-Wireless for full presentation
A light-emitting diode (LED) is an electronic light source. LEDs are based on the semiconductor diode. LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching
LEDs IN Traffic light
The new traffic lights you are seeing are made out of arrays of light emitting diodes (LEDs). These are tiny, purely electronic lights that are extremely energy efficient and have a very long life
TRADITIONAL HALOGEN BULBS V/S LEDs HALOGEN BULBSLEDs
Max. lamp lifetime six months Big brightness loss after only 5000 hours Not uniform brightness Long distance visualization problems
Max. LED lifetime 10 years Brightness loss after 10,000 hours between 6% to 12% Uniform brightness Long distance better view
TRADITIONAL HALOGEN BULBS V/S LEDs CONTD¦ HALOGEN BULBS
LEDs
Delay of the bulb in the on/off Yearly interior and exterior cleaning of the Lamp
On/off cycle delay is negligible No interior cleaning is necessary
ADVANTAGES
High-speed operation are available at low cost. FCC licenses are not necessary Penetrate through glasses, but not through walls LED light beams follow a straight-line path and are well suited for the wireless delivery of large quantities of voice and data information High directional features of LEDs
DISADVANTAGES
Suitable for short range only Intensity modulation with direct detection seems the only practical transmission method. As a communication medium, it has limited range. It is subjected to noise arising from sunlight, incandescent lighting,and fluorescent lighting.
APPLICATIONS
IN TRAFFIC LIGHT IN TRAFFIC INFORMATION SYSTEM IN MUSEUM
IN TRAFFIC LIGHT
Low power consumption and minimal required maintenance. Safety Long term warranty
IN TRAFFIC NFORMATION SYSTEM
Traffic light can be used as an audio broadcasting device. A receiver some distance away pointing at the traffic light can receive voice messages. The message can announce the time until the next signal change. Voice message can tell the location or directional information.
IN MUSEUM
Information be broadcast via a plurality of LEDs. One can listen to the audio message about the specific exhibit item
