No abstract

Abstract. In this paper, the finite element method (FEM) and experiment were adopted to evaluate the thermal performance and luminous flux of gas-cooled light-emitting diode (LED) filament lamp. The results show that the maximal temperature of the lamp with standard A55 glass bulb with four 1W LED elements can be limited under 140 °C. Air, nitrogen, helium are investigated as a gas filling of LED light bulb. The gas filling has a significant effect on the light flux and can change light flux of up to 15 percent. Characteristics of those gases also are object of this work. The effect of pressure on the thermal conductivity of gases inside the sealed glass bulb is estimated. This article discusses the results and provides recommendations for manufacturers of such lamps.

Five types of phosphors for LED ribbon beam elements in white LED lamps have been studied. The phosphor composition and colorimetric parameters have been researched during the experiment. It is found that the larger and more uniform the grains of the phosphor, the higher the emission efficiency. The most similar in color to the white color coordinates of the sample No. 5 phosphor having also higher brightness compared with samples No. 1 – No. 4.

No abstract