A developed method and measurement setup for measurement of noise generated in a supercapacitor is presented. The requirements for noise data recording are considered and correlated with working modes of supercapacitors. An example of results of low-frequency noise measurements in commercially available supercapacitors are presented. The ability of flicker noise measurements suggests that they can be used to assess quality of tested supercapacitors.

Thanks to a very high luminous efficacy of LED lamps (over 160 lm/W) they are the most preferred light sources in lighting applications today. The useful lifetime of LED modules exceeds 50,000 hours. Chromatic parameters of lamps making use of SSL (Solid State Lighting) have already equalled classic solutions, although they were noticeably worse not so long ago. High values of the Colour Rendering Index (CRI) and ease of control over the luminous flux cause that lamps with LEDs have become very attractive solutions. Today, the most important problem concerns LED drivers supplied from the 230 VAC mains. The lifetime of switched-mode converters, including electrolytic capacitors, is considerably shorter than that of LEDs. This paper discusses the features of alternative drivers for LED modules which are supplied directly from the 230 VAC mains and do not contain any electrolytic capacitors. In particular, power factor and efficiency of lamps with one or two LED strings are analysed and some hints concerning optimal design of such lamps are given. A unique feature of this work is a detailed analysis of harmonics contents in the supply current of such drivers, proving their conformity with the relevant standard. Finally, some problems associated with flicker resulting from the considered type of supply are mentioned.

This paper presents a portable exhaled breath analyser, developed to detect selected diseases. The set-up

employs resistive gas sensors: commercial MEMS sensors and prototype gas sensors made of WO3 gas

sensing layers doped with various metal ingredients. The set-up can modulate the gas sensors by applying

UV light to induce physical changes of the gas sensing layers. The sensors are placed in a tiny gas

chamber of a volume of about 22 ml. Breath samples can be either injected or blown into the gas chamber

when an additional pump is used to select the last breath phase. DC resistance and resistance fluctuations

of selected sensors using separate channels are recorded by an external data acquisition board. Low-noise

amplifiers with a selected gain were used together with a necessary bias circuit. The set-up monitors other

atmospheric parameters interacting with the responses of resistive gas sensors (humidity, temperature, atmospheric

pressure). The recorded data may be further analysed to determine optimal detection methods.