Approach to Remote Control and Detection of Degradation of LEDs in IoT Devices

This paper presents an approach to remote temperature control of a semiconductor light source (light-emitting diode - LED) with an unknown emissivity of the surface of its elements. We developed a testbed to study the thermal modes of LED modules and verify the proposed approach. In the experiment, the values of color temperature, direct voltage, full width at half maximum (FWHM), and the surface temperature of an LED module were obtained and analyzed. Based on the conducted studies, the temperature values obtained using the thermocouple, and thermal imager differ by no more than 3 °C. This fact confirms the adequacy and applicability of the proposed remote approach to the control of the temperature of the LED modules, including smart ones (based on the Internet of Things (IoT) technology). During the experiment, the correlated color temperature (CCT) of the LED module increased by about 60 K due to the luminophore degradation and the increase of the radiation intensity in the blue region of the spectrum. Further studies imply laboratory and practical experiments on remote temperature control of the LED modules with standard bulbs and IoT lighting devices.