Yazar "Ripka, P." seçeneğine göre listele

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    Characterisation of magnetic wires for fluxgate cores
    (Elsevier Science Sa, 2008) Ripka, P.; Butta, M.; Malatek, M.; Atalay, S.; Atalay, F. E.
    Orthogonal fluxgate sensors need only a single core and they can be made very small. We show how to measure properties of composite Cu/Py ferromagnetic wires to be used as cores for these sensors. Besides the well known axial loops we show how to measure the circumferential hysteresis loop and gating curves, which can directly be used for sensor modeling. It is generally believed that in composite wires the majority of the current flows through the copper core, thus reducing the possible perming effect of poorly magnetized core sections. We will show that this is true only at very low frequencies and for low magnetic layer thickness. The calculated values can be used as a starting point for FEM simulations. (c) 2007 Elsevier B.V All rights reserved.
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    Coil-less fluxgate effect in (Co0.94Fe0.06)72.5Si12.5B15 amorphous wires
    (Elsevier Science Bv, 2010) Atalay, S.; Ripka, P.; Bayri, N.
    In this study, the coil-less fluxgate properties of the as-cast and annealed amorphous wires with the composition (Co0.94Fe0.06)(72.5)Si12.5B15 were investigated. As its name implies, a coil-less fluxgate is a new type of magnetic-field sensor without a coil. When the wire is periodically saturated in a magnetic field in the circumferential direction with a 30 kHz, 62 mA driving current under a 16.5 pi rad/m torsional strain, there is a linear variation in the second harmonic of the voltage from the wire ends as a function of the applied external DC magnetic field along the length of the wire. Current-stress annealing of each sample improved the sensitivity of the coil-less fluxgate sensor. This is the first time that it has been shown that a linear change in the output of the coil-less fluxgate sensor. This is the first time that it has been shown that a linear change in the output of the coil-less fluxgate sensor can be obtained using torsion annealed wire without the necessity of twisting the wire during measurement. We showed that the linear operating range of the sensor can be increased by increasing the demagnetization factor in the sensing direction, so that the coil-less fluxgate sensor can be miniaturised just by reducing the wire length. (C) 2010 Elsevier B. V. All rights reserved.
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    Fluxgate effect in twisted magnetic wire
    (Elsevier Science Bv, 2008) Butta, M.; Ripka, P.; Atalay, S.; Atalay, F. E.; Li, X. P.
    In this paper a novel kind of fluxgate is presented. The sensor is based on helical anisotropy of the ferromagnetic layer, electrodeposited on copper wire. The saturating field is provided by current. owing in the wire, and the output voltage is measured directly at the terminations of the wire. Therefore no coils are necessary, making possible high miniaturization of the sensor. The effect has been tested twisting the wire: the second harmonic is shown to be strongly dependent on the applied torsion. Consideration on the practical use of the sensors is finally presented. (c) 2008 Elsevier B.V. All rights reserved.