Results 271 to 280 of about 152,057 (309)
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High frequency wideband power transformer design
[Proceedings] 1992 IEEE International Conference on Systems, Man, and Cybernetics, 2003The transmission line transformer (TLT) is presented as a viable solution to the problem of high-frequency/wideband transformer design for the latest high frequency DC-DC resonant converters. Utilizing transmission line circuit theory, the authors present the characteristics of the TLT. Turn ratio 2:1 and 3:1 TLT prototypes with isolation were designed
D. Gan +3 more
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High-Frequency Planar Transformer Parameter Estimation
IEEE Transactions on Magnetics, 2015This paper presents different methods to determine the parameters for the equivalent electrical circuit model of a high-frequency planar transformer. The first method is implemented in the circuit simulation software utilizing a 1-D electromagnetic analysis.
Lew Andrew R. Tria +2 more
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High–Frequency Transformation of Penicillium Chrysogenum
Nature Biotechnology, 1987We report high–frequency transformation of penicillin–producing strains of Penicillium chrysogenum using plasmid vectors carrying the pyr4 gene of Neurospora crassa. Transformation to stable uracil independence is associated with acquisition of transforming DNA in high molecular forms that are not simple multimers of the vector.
J. M. Cantoral +4 more
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A new type high frequency transformer
IEEE Transactions on Magnetics, 1991In order to realize small power supplies, the authors propose a type of coreless high-frequency transformer. This transformer is composed of simple twisted coils and its operating principle is based on the skin effect of current carrying conductors. Approximate analysis based on the symmetrical current distributions in each of the coil axes has been ...
S. Hayano +3 more
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Modeling of high-frequency micro-transformers
IEEE Transactions on Magnetics, 2004A dynamic model has been developed to predict the efficiency of a micro-transformer, operating at 5 MHz. The model includes a core hysteresis model, core eddy current model and winding copper loss model. Measurements and finite element analysis were carried out in order to validate the model.
null Ningning Wang +5 more
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High-Frequency Impedance Transformations
2010Active devices such as transistors or Op-Amps have bandwidth limitations that can result in instability or undesirable dynamic response in feedback circuits. As gain decreases with frequency, feedback-amplifier port-resistance values also change and effectively become reactive. These bandwidth-related reactances can resonate with other circuit elements.
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High-frequency thin-film piezoelectric transformers
2012 IEEE International Frequency Control Symposium Proceedings, 2012A voltage step-up/impedance transformer is presented which operates by modifying the electrode configuration of lateral-extensional mode thin-film piezoelectric-on-substrate (TPoS) resonators. The individual electrode pairs that cover the stress concentration areas of a 10th order harmonic 30MHz resonator are connected in series at the output port to ...
Hediyeh Fatemi, Reza Abdolvand
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Design considerations for high power high frequency transformers
21st Annual IEEE Conference on Power Electronics Specialists, 2002Various design considerations for high-power (multikilowatt), high-frequency transformers for DC-DC power converters are investigated. Although Ferrite (PC40) is lossier than Permalloy80 (0.5 mil) at the frequencies of interest (25-50 kHz) the use of the former is justified on the basis of cost, weight, and wide ranges of shapes.
M.H. Kheraluwala +2 more
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Calculation of Leakage Inductance for High-Frequency Transformers
IEEE Transactions on Power Electronics, 2015Frequency-dependent leakage inductance is often observed. The high-frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high-frequency leakage inductance and proposes an accurate prediction ...
Ouyang, Ziwei +2 more
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High voltage, high frequency transformer switching converter integration
IET Conference on High Power RF Technologies, 2009This paper presents a high voltage (HV), high frequency (HF) transformer with high voltage rectifier. The described systems employ a low profile HV, HF transformers and voltage bridge technology multiplier. A model of the converter of 150 kW is presented and verified by Saber simulator.
T. Filchev +3 more
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