How many LEDs are in this red traffic light?
| Note the difference in the color between the LEDs at the top of the
and the incandescent bulb/red lens at the bottom of the picture.
|The housing has been opened to reveal the 135 W lamp and the reflector of the traditional red traffic light.|
|Looking north on Park St. at University Ave. in the heart of the University of Wisconsin - Madison campus. Note the three red LED traffic lights.|
|Close up of red LED traffic signal. The 680 LEDs draw a total of 25 watts of power.|
|Click here to view emission spectra of traffic signals, both incandescent and LED.|
|Solar powered portable LED traffic signal. Solar cells are used to charge batteries of this LED traffic signal. Two of these signals are linked by radio across a one-way bridge while the bridge is being replaced. The green and red of the high signal have been used for target practice yet they still function. Highway NN Dunklin County, MO. Click here for more photos of this site.|
Wiring mistakes can even happen with LED traffic lights.
Notice the correct yellow signal across the street with both
red and green showing on the near signal.
Additive color mixing anyone!
For more information about LEDs in traffic lights see these suppliers:
Shin Bon Eng. Co. Ltd.
LED Traffic Lights at:
Research Center, School of Architecture, Rensselaer Polytechnic Institute
SUMMARY OF LED AND TRAFFIC SIGNAL TECHNOLOGY