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Role Of Photo Dimmer Sensors In LED Traffic Directors

March 08, 2023

LED traffic directors have become a prominent feature in emergency vehicles, in particular, utility vehicles. It makes it easier for drivers to navigate the roads and for other motorists to follow the rules. But what makes these devices so effective is not just their bright lighting, but also their sophisticated photo-dimmer sensors. In this article, the role of photo dimmer sensors in LED traffic directors will be examined via a prominent mechanism.


What are dimmer sensors in an LED?


Dimmer sensors are used in LED traffic directors to control the brightness or intensity of the LEDs. By controlling the intensity of the LEDs, dimmer sensors help to improve visibility and safety for drivers and pedestrians. 


How to dim an LED?


Pulse Width Modulation

Pulse Width Modulation, or PWM, is a common technique for controlling the intensity of LEDs. By rapidly turning the LED on and off at a high frequency, the average power delivered to the LED can be controlled. PWM controllers are available in a variety of sizes and capabilities. The size and capability of the controller will determine how many LEDs can be controlled and at what intensity.


When selecting a PWM controller for an LED application, it is important to consider the switching frequency or refresh rate of the controller. The refresh rate determines how often the LED is turned on and off and should be matched to the specific application. It is also important to consider the voltage and current capabilities of the controller. The voltage must be high enough to support all of the LEDs in the circuit, and the current must be able to provide enough power for all of the LEDs at their full brightness.


For complete fleet solutions including traffic arrows, police sirens, perimeter lighting and more, check out D&R Electronics Co. Ltd., a firm believer in providing solutions through innovation. Our 40+ years of enriched experience and knowledge working with police and public work departments around the globe is a definite advantage, further strengthened by our after-sales service policies. For more information, visit

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