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73 results for “High voltage”
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Research ArticleOpen accessIn the abstractA Novel Method for Testing Digital to Analog Converter in Static RangeK. Hariharan, S. Gouthamraj, B. Subramaniam et al.Problem statement: Linearity testing methods for DAC usually involves usage of non-linear analog components, which are indeed prone to various errors. Few other testing methodologies involve complex circuitry for measuring exactitude of DAC. Practically, it is difficult to build those as Built In Self Test (BIST) due to complexity of calculation, which demands more usage of ALU (or core of … …American Journal of Applied Sciences, Vol. 7, Issue 8 · 31 Aug 2010 · 7,458 accessesView PDFCite
Research ArticleOpen accessIn the abstractInfluence of Process Parameters on Electrical Discharge Machined Job Surface IntegrityA.K.M. Asif Iqbal, Ahsan Ali KhanProblem statement: Electrical Discharge Machining (EDM) is the most widely used non conventional machining process for removing material from workpiece by means of a series of repeated electric discharges. Electrical Discharge milling (ED-milling) is an emerging technology where a cylindrical tool electrode follows a programmed path in order to obtain the desired shape of a part. During machining of metals … …American Journal of Engineering and Applied Sciences, Vol. 3, Issue 2 · 30 Jun 2010 · 8,584 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Novel Low-Power CMOS Operational Amplifier with High Slew Rate and High Common-Mode Rejection RatioIsmail Nabhan, Moussa AbdallahProblem statement: High speed operational amplifier is always an on-going research topic since major high speed application are needed. Approach: A two-stage operational amplifier (op amp) is designed, simulated and fabricated using a UMC 0.5 μm 2P2M CMOS technology. Results: This chip includes a compensation technique to ensure stability and zero systematic input-offset-voltage. The fabricated chip achieves a 84 dB … …American Journal of Engineering and Applied Sciences, Vol. 3, Issue 1 · 31 Mar 2010 · 8,237 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Dynamic Voltage Restorer for Voltage Sag Mitigation in a Refinery with Induction Motors LoadsTarek I. El-Shennawy, Abdel-Mon’em Moussa, Mahmoud A. El-Gammal, Amr Y. Abou-GhazalaProblem statement: ANRPC is a refinery based in Alexandria, Egypt. The plant was subjected to several shutdowns due to tripping of large induction motors, either by under voltage or by over current relays, sometimes by the mechanical protection. The main cause for such unplanned shutdowns was voltage sags. The Dynamic Voltage Restorer (DVR) has recently been introduced to protect the … …American Journal of Engineering and Applied Sciences, Vol. 3, Issue 1 · 31 Mar 2010 · 8,922 accessesView PDFCite
Research ArticleOpen accessIn the abstractApplication of Direct Current and Temperature Stresses of Low-Voltage ZnO Based Varistor CeramicsM. G.M. Sabri, B. Z. Azmi, Zahid Rizwan et al.Problem statement: The stresses to humidity, DC and AC bias, multiple impulse voltages and high temperatures are known to affect the varistor performance and it is also interesting to know the effect of both DC bias and temperature stresses at the same time. Approach: Here, the simultaneous DC and temperature stresses degradation was investigated to see the changes of nonlinear … …American Journal of Applied Sciences, Vol. 6, Issue 8 · 31 Aug 2009 · 8,379 accessesView PDFCite
Research ArticleOpen accessIn the abstractLow Power Phase Locked Loop Frequency Synthesizer for 2.4 GHz Band ZigbeeNesreen Mahmoud Hammam Ismail, Masuri OthmanProblem statement: Wireless communication systems are required for many applications. There are different standards for these systems. IEEE 802.15.4 defines the communication system standard for zigbee. This study discussed designing one of the blocks of zigbee transceiver which is the Phase Locked Loop (PLL). A major target for any communication systems is saving battery power, especially for zigbee as it … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 2 · 30 Jun 2009 · 8,057 accessesView PDFCite
Research ArticleOpen accessIn the abstractInverse Sine Phase Detector Phase Locked Loop Associated with Modified Multi Band LC Quadrature Voltage Controlled Oscillator for Wireless Communication Systems at 0.9, 1.8, 2.4, 3.5 GHzMahmoud AbdellaouiProblem statement: In this study and in consequence of the restricted performance of the multi standard wireless receiver utilizing the classical architectures, we proposed and presented a new architecture of multi band wireless receiver based on an Inverse Sine Phase Detector Phase Locked Loop (ISPDPLL) associated with modified multi band LC quadrature Voltage Controlled Oscillator (VCO), supporting GSM/DCS/DECT/Bluetooth/WiMax systems. Approach: … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 2 · 30 Jun 2009 · 8,251 accessesView PDFCite
Research ArticleOpen accessIn the abstractVoltage Collapse Risk Associated to Under-Voltage Capacitive Compensation in Electric Power System OperationHeraldo Silveira Barbuy, Alexandre Rocco, Luiz Augusto Pereira Fernandes, Geraldo Caixeta GuimarãesProblem statement: In the operation of an Electric Power System (EPS), it has been usual to provide reactive power injection to avoid an under-voltage bus condition. In some situations an adequate voltage profile will not be a guarantee against Voltage Collapses (VCs) that may cause blackouts as seen in many occurrences around the world. The repeatedly injection of reactive power … …American Journal of Applied Sciences, Vol. 6, Issue 4 · 30 Apr 2009 · 7,253 accessesView PDFCite
Research ArticleOpen accessIn the abstractAn Assessment of the Electric Power Quality and Electrical Installation Impacts on Medical Electrical Equipment Operations at Health Care FacilitiesMário César Giacco Ramos, Carlos Márcio Vieira TahanProblem statement: Medical electrical equipments at health care facilities presented malfunction and wrong medical information due to poor electric power quality and to inadequate electrical Installations. Some equipment such as X-ray, computerized axial tomography and magnetic resonance imaging are considered as polluting ones due to their high amount of harmonics and voltage transients produced on the electrical power supply when … …American Journal of Applied Sciences, Vol. 6, Issue 4 · 30 Apr 2009 · 7,514 accessesView PDFCite
Research ArticleOpen accessIn the abstractDesign Analysis of High-Speed Axial-Flux GeneratorM. Sadeghierad, A. Darabi, H. Lesani, H. MonsefProblem Statement: Axial flux permanent magnet machines are regarded as compact high efficiency generators for micro-turbines employed in the distributed power generation systems. High-speed rotor of the generator causes some designing and modeling problems. Sensitivity analysis tasks of the machine parameters are difficult and completely different in comparison with the problems associated with conventional machines. Approach: This article presents a … …American Journal of Engineering and Applied Sciences, Vol. 1, Issue 4 · 31 Dec 2008 · 7,559 accessesView PDFCite