Open Access

Neue Erkenntnisse zur Wichtigkeit ausreichender Tageslichtversorgung im Innenraum haben planungsrelevante Änderungen normativer Vorgaben nach sich gezogen. Renate Hammer und Mathias Wambsganß veranschaulichen die neuen Anforderungen und erläutern die Möglichkeiten zur planerischen Umsetzung. Die Autoren klären, wann Tageslichtversorgung und Besonnung als ausreichend gelten, welche Qualitäten die Sichtverbindung nach außen erfüllen muss und wie Blendung durch Tageslicht zu begrenzen ist. Angaben zur melanopischen Wirkungsweise von Tageslicht bieten einen Einstieg in den planerischen Umgang mit nicht-visuellen Kriterien. Ein weiteres Kapitel zeigt die Schnittstellen mit anderen Aspekten der Bauplanung.

One major problem of a continuous process like plastic extrusion is their incapability to deal with non-local gas pressure. This is an inherent problem because a continuous process has an open end in the feeding port where pressure can escape. In this study a novel feeding system was developed to enable granulate feeding into gas pressurized processes inside a single- or twin-screw extruder. With this apparatus gas pressure can be applied inside the extrusion process. The apparatus separates the pressurized extruder from the dosing equipment that feeds the extruder. It keeps the pressure inside the system while continuously feeding new material into the process. A small-scale prototype was designed for proof-of concept. The small size of the prototype was able to handle small amounts of granulates of around 100 - 200 g/h. An applied gas pressure of 8 bar was achieved. In future optimizations, throughput can be increased and maximum applied gas pressure towards 15-20 bar.

We present inductive power transfer (IPT) with a half-bridge converter based on differential relaxation self-oscillation. The oscillation dynamics of the converter automatically adapts to variation in the inductive coupling link and changes in the load, respectively. Design equations based on theoretical circuit analysis reveals a high power transfer efficiency (>90%) for alteration of coupling distance in the strong coupling regime. A prototype system employing GaN-HEMTs confirms the theoretically predicted characteristics of the proposed circuit.

We present a novel differential relaxation oscillator for inductive power transfer. The proposed oscillator offers an automatic adaption of the oscillation period to a change in the power link impedance, which ensures a high efficient operation for variable loads and coupling factors. A detailed circuit model of the self-oscillation system is provided with analytical design equations. We find a large self-oscillation range for variable coupling factors and loads. The theoretical results are confirmed by circuit simulation and measurements carried out on a low-power demonstrator system. We demonstrate non-resonant and robust self-adaption of the relaxation oscillator to coupling factors ranging from k=0.6-0.9.