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The purpose of the paper is to investigate the various modulation types for control of transformerless non-dimmable AC/DC/DC converters in nominal operation mode intended for LED illuminants. A combined PWM (pulse width modulation) is investigated. The optimal selection of power converter inductor core is considered. The derived results lead to conclusions for improvement of the power converter characteristics. Furthermore, the DC link capacitor is reduced without significant effect on circuit performance. It is proven that utilizing combined PWM would result in less current ripple and improved power factor. Utilization of nanocrystalline materials additionally reduces losses in the examined power converter. [ABSTRACT FROM AUTHOR]

The paper presents improvement on operation time of cell balancing algorithm compared to conventional multiple cell LiFePO4 charge methodology. A flowchart is synthesised to explain the main steps of the software design, which afterwards is implemented in a microcontroller. Experimental results are provided to clarify the transition between charge and balance process. Graphical data for a voltage equalization of eight cells is presented to verify the proposed improvement. [ABSTRACT FROM AUTHOR]

This paper presents current stage and future trends of magnetic properties, advantages and applications of nanocrystalline magnetic materials in electronics. The advanced magnetic properties of the material are discussed and compared with properties of other magnetic materials. Typical relations of initial permeability, saturation induction and operating frequency are depicted to prove the advantages of these alloys. The ability to control their B-H loop, to operate at high temperatures and their low losses are shown to prove the corresponding dominant applications. Novel grades of nanocrystaline alloys are addressed to focus on the further improved characteristics. Typical and new applications of nanocrystalline materials in Electronics and Power Electronics are discussed. It is concluded that because of their advanced magnetic and operating properties the nanocrystalline materials are very prospective in future electronic equipment. [ABSTRACT FROM AUTHOR]