Solar traffic lights are signaling devices powered by solar panels positioned at road intersections, pedestrian crossings and other locations to control the flows of traffic. They assign the right of way to road users by the use of lights in standard colors (red - amber/yellow - green), using a universal color code (and a precise sequence to enable comprehension by those who are color blind). Most of the solar traffic lights have battery back-up for functioning during night.
In the typical sequence of colored lights:
• Illumination of the green light allows traffic to proceed in the direction denoted, • Illumination of the yellow/amber light denoting, if safe to do so, prepare to stop short of the intersection, and • Illumination of the red signal prohibits any traffic from proceeding. Usually, the red light contains some orange in its hue, and the green light contains some blue, for the benefit of people with red-green color blindness, and "green" lights in many areas are in fact blue lenses on a yellow light (which together appear green).
Most solar traffic lights use LED lamps as they are more reliable and have more advantages over other lighting devices like CFL lamps as they are more energy efficient, have a longer life span and turn on and turn off quickly. Solar traffic lights contain enclosures which house the batteries and the control panel circuitry.
The other parts in a solar traffic light include a charge controller to control the charging and discharging of the battery and a countdown timer which displays the amount of time left before the battery discharges fully.
• Solar traffic lights are self sufficient as they do not require external power sources. • They are easy to set up and operate.
• They require very little to no maintenance as they have no moving parts
Traffic lights can have several additional lights for filter turns or bus lanes. This one in...