Passive Power Filters

Power converters require passive low-pass filters which are capable of reducing voltage ripples effectively. In contrast to signal filters, the components of power filters must carry large currents or withstand large voltages, respectively. In this paper, three different suitable filter structures for d.c./d.c. power converters with inductive load are introduced. The formulas needed to calculate the filter components are derived step by step and practical examples are given. The behaviour of the three discussed filters is compared by means of the examples. Practical aspects for the realization of power filters are also discussed.Comment: 25 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

Thermal Design of Power Electronic Circuits

The heart of every switched mode converter consists of several switching semiconductor elements. Due to their non-ideal behaviour there are ON state and switching losses heating up the silicon chip. That heat must effectively be transferred to the environment in order to prevent overheating or even destruction of the element. For a cost-effective design, the semiconductors should be operated close to their thermal limits. Unfortunately the chip temperature cannot be measured directly. Therefore a detailed understanding of how losses arise, including their quantitative estimation, is required. Furthermore, the heat paths to the environment must be understood in detail. This paper describes the main issues of loss generation and its transfer to the environment and how it can be estimated by the help of datasheets and/or experiments.Comment: 17 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

T_0*-compactification in the hyperspace

A *-compactification of a T0 quasi-uniform space (X,U) is a compact T0 quasi-uniform space (Y,V) that has a T(V∨V−1)-dense subspace quasi-isomorphic to (X,U). In this paper we study when the hyperspace with the Hausdorff–Bourbaki quasi-uniformity is *-compactifiable and describe some of its *-compactifications.Kunzi, HA.; Romaguera Bonilla, S.; Sanchez Granero, MA. (2012). T_0*-compactification in the hyperspace. Topology and its Applications. 159:1815-1819. doi:10.1016/j.topol.2011.06.064S1815181915

Quasi-pseudo-metrization of topological preordered spaces

We establish that every second countable completely regularly preordered space (E,T,\leq) is quasi-pseudo-metrizable, in the sense that there is a quasi-pseudo-metric p on E for which the pseudo-metric p\veep^-1 induces T and the graph of \leq is exactly the set {(x,y): p(x,y)=0}. In the ordered case it is proved that these spaces can be characterized as being order homeomorphic to subspaces of the ordered Hilbert cube. The connection with quasi-pseudo-metrization results obtained in bitopology is clarified. In particular, strictly quasi-pseudometrizable ordered spaces are characterized as being order homeomorphic to order subspaces of the ordered Hilbert cube.Comment: Latex2e, 20 pages. v2: minor changes in the proof of theorem 2.

Logic Programs for Primitive Recursive Sets

Meyer and Ritchie have previously given a description of primitive recursive functions by loop-programs. In this paper a class of logic programs is described which computes the primitive recursive sets on Herbrand universes. Furthermore, an internal description of primitive recursive functions and sets on Herbrand universes is give

A note on uniform ordered spaces

We characterize the generalized ordered topological spaces X for which the uniformity (X) is convex. Moreover, we show that a uniform ordered space for which every compatible convex uniformity is totally bounded, need not be pseudocompac