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Input Voltage (input + voltage)
Selected AbstractsA White LED Driver Using a Buck,Boost ConverterIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2010Kei Eguchi Member Abstract For mobile backlighting applications, a white LED (WLED) driver using a buck,boost converter is proposed in this letter. Unlike conventional converters using boost converters, 2×/1.5× charge pumps, and so on, the proposed converter offers the negative stepped-down voltage to drive the LED's cathode only when the input voltage is insufficient to drive a 1× transfer mode. Furthermore, unlike the LED backlight using charge pumps, the proposed converter can adjust the output voltage by controlling the duty factor of the clock pulse. Thus, the proposed converter can realize high power efficiency. The validity of the proposed converter is confirmed by simulations and experiments. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Synthesis of general impedance with simple dc/dc converters for power processing applicationsINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 3 2008J. C. P. Liu Abstract A general impedance synthesizer using a minimum number of switching converters is studied in this paper. We begin with showing that any impedance can be synthesized by a circuit consisting of only two simple power converters, one storage element (e.g. capacitor) and one dissipative element (e.g. resistor) or power source. The implementation of such a circuit for synthesizing any desired impedance can be performed by (i) programming the input current given the input voltage such that the desired impedance function is achieved, (ii) controlling the amount of power dissipation (generation) in the dissipative element (source) so as to match the required active power of the impedance to be synthesized. Then, the instantaneous power will be automatically balanced by the storage element. Such impedance synthesizers find a lot of applications in power electronics. For instance, a resistance synthesizer can be used for power factor correction (PFC), a programmable capacitor or inductor synthesizer (comprising small high-frequency converters) can be used for control applications. Copyright © 2007 John Wiley & Sons, Ltd. [source] The First Teleautomatic Low-Voltage Prosthesis With Multiple Therapeutic Applications: A New Version of the German Artificial Sphincter SystemARTIFICIAL ORGANS, Issue 8 2010Olaf Ruthmann Abstract To date, there are no artificial sphincter prostheses for urinary or fecal incontinence that may be implemented elsewhere instead, for example, in the upper gastrointestinal tract. Conventional systems are conceptually similar but are constructed specifically for distinct applications and are manual in operation. The German Artificial Sphincter System (GASS) II is the evolution of a highly integrative, modular, telemetric sphincter prosthesis with more than one application. Redesigning and integrating multilayer actuators into the pump allows us to reduce the input voltage to ,10 to +20 V (VPP = 30 V). This provides for a flow rate of 2.23 mL/min and a counterpressure stability of 260 mbar. Furthermore, multiple applications have become feasible due to our standardized connection system, therapy-specific compression units, and application-specific software. These innovations allow us to integrate not only severe fecal and urinary incontinence, erectile dysfunction, and therapy-resistant reflux disease, but also morbid adiposity into the gamut of therapeutic GASS applications. [source] Structures and modulation algorithms of direct ac/ac converters with two legs and three legs for two-phase systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2010Sangshin Kwak Abstract Two-phase ac/ac matrix converter configurations are presented based on direct power conversion processes from three-phase input ac supplies to two-phase output ac loads. Two types of two-phase matrix converter topologies, utilizing the standard matrix converter configuration, are introduced with two-leg and three-leg based structures. Pulse width modulation (PWM) strategies with high-frequency composition for the two-leg and the three-leg based two-phase matrix converters are developed to synthesize sinusoidal output waveforms of two-phase loads from time-varying input ac voltages. Grounded on the developed modulation algorithms, the presented matrix converters directly generate controllable two-phase output voltages from sinusoidal input voltages with no intermediate dc conversion and concomittant dc-link elements. The proposed matrix converters can provide sinusoidal output current/voltage waveforms with independently controlled magnitude and 90° phase angle to two-phase loads. Thus, the converters are effective for both balanced and unbalanced two-phase loads. The presented two-phase operations with the standard matrix converter structures add the versatility for the matrix converter systems to function in multi-phase loads as a universal converter. Simulation and experimental results are presented to verify the developed modulation techniques and the converter configurations for the two-phase matrix converters. Copyright © 2009 John Wiley & Sons, Ltd. [source] Generalised algorithm of novel space vector modulation: for N -level three-phase voltage source inverterEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2008Hachemi Chekireb Abstract This paper concerns the development of a generalised algorithm of a novel space vector modulation (SVM) for N -level three-phase voltage source inverter. It is considering that the (N,1) DC input voltages of inverter are constant. The proposed method ensures initially the determination of the N3 inverter switching states, the extraction of the redundancies to obtain 3N(N -1),+,1 independent switching states and their organisation by sector in six distinct matrices Wk with k,=,(1,,,,,6). After that, these matrices Wk with k,=,(2,,,,,6) are ordered as the matrix W1 related to the first sector. So, the research of the three closest vectors to the reference vector is carried out only in first sector and for this purpose, the equivalent reference vector is introduced which is resulting from the rotation by ,(k,1),/3 of the reference vector. The on-line choice of the three vectors (three switching states of the inverter) is based on the distances between the equivalent reference vector and some vectors located in its vicinity in the (,,,) plane of the first sector. Moreover, a simple method for the calculation of the duty cycles for these three switching states is proposed which exploits directly the three shortest distances associated to these three selected vectors. The sequence of these three switching states over a sampling period is investigated in view to reduce the harmonic contents of the voltage output. The application is carried out on an N -level three-phase voltage source inverter, where N is an arbitrary odd integer. Finally, the phase voltage and its harmonic spectrum provided by a three-phase N- level inverter with N,=,(3,5,7,9,13,15) are presented to confirm the generalisation of this method. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||