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Full-Text Articles in Engineering
Aeroelastic Energy Harvesting Using A Nonlinear Electromagnetic Oscillator, Katherine Bender, Ndungu Muturi, Alex Spies, Christopher Lee
Aeroelastic Energy Harvesting Using A Nonlinear Electromagnetic Oscillator, Katherine Bender, Ndungu Muturi, Alex Spies, Christopher Lee
Christopher Lee
Results are presented from the design, fabrication and testing of an electromagnetic-inductor device to convert aeroelastic-induced oscillations of an airfoil into electricity. The energy harvester consists of three magnets configured such that the force-displacement relationship can be described by a fifth-degree polynomial. the integration of the harvester into a two-degree-of-freedom, pitch/plunge airfoil system introduces nonlinear stiffness into the plunge direction. This nonlinearity gives rise to limit cycle oscillations which, in turn, are converted to electric power by the harvester. Experimental measurements from wind tunnel tests are compared to predictions of limit cycle response and resulting power generation using a two-degree-of-freedom …
Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti
Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti
José Oscar Mur-Miranda
Wireless power transfer can create the illusion of portable devices with infinite power supplies. Power transfer using magnetically coupled series resonators is maximized when the load presented to the sender is matched to the series impedance of the source. This determines an optimal separation distance between the sender and the receiver. However, the maximum power transferred only depends on the losses in the system and is independent of this distance and the resonant frequency. Closed-form expressions describe the power transferred and efficiency for all distances and system values. These expressions are validated with systems operating at 23 kHz, 40 kHz …
Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe
Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe
José Oscar Mur-Miranda
Wireless power transfer can create the illusion of portable devices with infinite power supplies and enable applications that are currently unimaginable because of power constraints. Magnetic induction has been extensively used for wireless power transfer, but its efficiency depends on magnetic coupling that decays as the inverse cube of distance. At long enough distances, the magnetic coupling is weak enough that the effect of the receiver coil on the sender coil can be neglected. In this weakly coupled limit, series resonance in both the sender and the receiver increases the power transfer. Compared to magnetic induction, the power transfer increases …
Evolution Of A Folded Floating-Gate Differential Pair, Bradley Minch
Evolution Of A Folded Floating-Gate Differential Pair, Bradley Minch
Bradley Minch
The author presents a folded floating-gate MOS (FGMOS) differential pair circuit that is capable of simultaneously providing a rail-to-rail common-mode input voltage range and a rail-to-rail output voltage swing with a low power-supply voltage. In this configuration, the voltage drop across the bias current source is folded up into the same range over which the output voltages swing, facilitating low-voltage operation. The floating-gate charge can be used to trim out the offset voltage of the differential pair and to reduce the required power-supply voltage for a given bias current level. The author provides both a qualitative description of how the …