Abstract. At the present there is a wide variety of step down converters on market. Due to differences in converter's prices, parameters and principles of function, it is not that easy to choose a proper one suitable for a concrete application. Moreover, really strict standards are applied in order to achieve high EMC compatibility between different devices. This article tries to show the possibilities of a really low-end DC/DC converter controller AOZ 1284. The set of measurements according to the set specifications and standard EN 61000-6-3 are presented together. Moreover, measures needed to comply to limits of the standard are shown along with it's results.

Abstract. Most remote controllers for entrance gates operate on free frequencies 433 or 868 MHz. However, this technology limits the user comfort, as it is usually not common that bi-directional communication is established. A higher comfort of controlling the entrance gates can be achieved by employing the GSM network for transmission of commands and messages between the gate controller and the user. In this case, only a conventional GSM cellular phone is needed to control the gate. A description of such a controller based on the GSM module and Arduino controller is provided in this paper.

Paper describes suggestions on the improvement of the common On-line structure of the uninterruptable power supply units used for powering of network devices. According to these suggestions a prototype circuit able to deliver the output power up to 150 W was constructed. The topology was optimized in order maximum efficiency was achieved when the output is fed by an accumulator in order the operating time was as long as possible.

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The spurious aka counterfeit components represent still a serious danger for functionality, reliability and lifetime of any electronic device these components are part of its manufactured assembly. There exist a lot of methods aimed at revealing counterfeit components before they are used in electronic module production. Those methods differ in complexity and also in counterfeit component filtering yield. In short, any efficient method based on specification parameters manifestation, functionality and appearance comparison is applicable. This presentation illustrates the diagnostic abilities of some representative methods for counterfeit components preventive filtering from a production process. As a result of our research activities, the capability of popularly known Analogue Signature Analysis method is mentioned and illustrated as well as laser decapsulation method and a comparison of visual features accentuated with light exposure.