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Validation and calibration of Electrothermal Device Models Using Infrared Laser Probing Techniques
(1998)
Enhanced inductive power transmission (IPT) between coaxially arranged circular coils is introduced by time-modulation of the mutual inductance. This modulation is accomplished by coherent switching of the short circuit current induced in a third loop. An analytical circuit model supporting the design for future time-modulated IPT systems is derived. We demonstrate an increase in load rms-voltage by 13% (28% gain in power) compared to an unmodulated transfer on an experimental system operating at fundamental frequencies ranging from 40kHz to 500kHz.
Due to their lightweight potential and good eco-balance, thermoplastic hybrid composites with natural fiber reinforcement have long been used in the automotive industry. A good alternative to natural fibers is wood fibers, which have similar properties but are also a single-material solution using domestic raw materials. However, there has been hardly any research into wood fibers in thermoplastic back-injected hybrid composites. This article compares the bond strength of an injection molded rib from polypropylene (PP) and wood fibers to different non-wovens. The non-wovens consisted of wood fibers (spruce) or alternatively natural fibers (kenaf, hemp), both with a polypropylene matrix. Pull-off and instrumented puncture impact tests show that, given similar parameters, the natural and wood-fiber-hybrid composites exhibit very similar trends in bond strength. Further tests using viscosity measurements, microscopy, and computed tomography confirm the results. Wood-fiber-reinforced thermoplastic hybrid composites can thus compete with the natural fiber composites in terms of their mechanical behavior and therefore present a good alternative in technical semi-structural applications.
A DDR2 DRAM test setup is developed and implemented on the Griffin III ATE test system from HILEVEL Technologies. The test system provides a raw platform for performing various mixed signal and digital tests. In order to configure patterns easily in a vector format, a software platform is developed to manage test patterns according to the user's analysis needs. As examples, retention test patterns with disabled self-refresh are applied to 2 Gbit DDR2 SDRAM of two different DRAM vendors. The devices are characterized in respect to their intrinsic leakage and data retention behavior under the influence of stress conditions such as temperature or access algorithm. The tests are automated and test data is logged for an off-line data analysis. Data is recorded before and after solder simulation steps in order to observe a retention time degradation.
The System HAILsens implements a device for Real-Time sensor data processing, running on a Texas Instruments Concerto M3 core. An I2C interface is used for sensor communications. Ethernet with UDP on a custom developed three layered frame organisation of sensor data serves as a link to the main system on board of an aeroplane. For backing up the acquired data, all frames are locally stored on an SD Card. To have the possibility of easily checking the current system status, an LCD module and a push-button provide a minimal user interface.