Operation of Electronic Devices for Controlling Led Light Sources When the Environment Temperature Changes

Abstract

Ambient temperature significantly affects the electrical and light parameters of LEDs, such as forward and reverse current, voltage drop LEDs and luminous flux. With an increase in temperature, the decrease in the intensity of LED radiation is explained by physical processes, including the phenomena of non-radiative recombination due to impurity levels, recombination on the surface, losses carriers in the barrier layers of heterostructures, etc. The increase in temperature is also significantly reduces the useful life of LEDs and the LED device in general. Drivers, which allows to stabilize the operating current with a change in the supply voltage of the device and, as the result is light flux. But in LEDs of various types, current stabilization does not lead to the stabilization of the light flux when the temperature regime of their operation changes. When changing ambient temperature in the range of +40…+60 °C, the luminous flux of LEDs is significant decreases even in the case when their current is kept constant, as we can see from documentation for most of LED types. An article analyzes the effect of temperature on electrical and light parameters LEDs with different types of drivers as part of LED lighting devices, such as LED lamps and LED spotlights, in order to offer possible constructive solutions for partial reduction or elimination of the decline problem luminous flux of LED devices under conditions of their operation at high temperatures.

Surface Illumination as a Factor Influencing the Efficacy of Defect Recognition on a Rolled Metal Surface Using a Deep Neural Network

“…The power consumption in industrial conditions can be reduced by lighting devices based on semiconductor light sources, the main advantages of which include high luminous efficiency, long service life, and environmental friendliness [28]. The standard values of qualitative and quantitative light parameters can be ensured by increasing the power and, consequently, the light flux coming out of lighting devices at the level of the diagnosed surface of the metal strip, which leads to a variation in the illuminance level.…”

Research Control Devices for LED Light Sources under Their Operating Conditions at Elevated Temperatures

“…In recent years, light-emitting diodes (LEDs) light sources have become widely used. As the analysis shows, in most drivers used to control LEDs in LED lighting devices, there is no compensation for changes in the light parameters of LEDs or LED matrices when the temperature regime of their operation changes, although temperature significantly affects the electrical and light parameters of LEDs [1][2][3].…”

“…The temperature dependence luminous flux of LEDs is most significant in cases of using LEDs in some industrial halls, outdoor conditions, etc., when their luminous flux significantly decreases with increasing temperature [2,18]. To compensate for this decrease, it becomes necessary to increase the LED current rather than keeping it constant [19,20].…”