Sensorless converter for low-power LED lamp with improved power factor

The implementation of power factor correction for electronic ballasts in lighting applications usually is related with additional costs. Besides the requirements for power factor and total harmonic distortion in European standard IEC 1000-3-2 (class C) are defined only for lighting products above 25 W. All this discourages the manufacturers from the implementation of power factor correction for small power devices. This paper considers the possibility to implement power factor correction for non-dimmable small power LED drivers using very small or even no additional investments. The idea and preliminary calculations of the proposed converter are discussed at the beginning of the paper. The simulations of different configurations of the converter as well as the results of these simulations are discussed then. The following section describes the experiments and summarizes the results of these experiments. Finally the conclusions are given at the end of this article.