Browsing Publikační činnost ČVUT by Author "Ripka P."

Now showing items 1-20 of 74

    • A 3-Phase Current Transducer based on microfluxgate sensors 

      Author: Ripka P.; Grim V.; Chirtsov A.
      (Elsevier, 2019)
      Novel 3-phase DC/AC current transducer for 3-phase current lines is based on 8 integrated fluxgate sensors. Using full information from each sensor rather than gradiometric pairs, we suppress crosstalk between individual ...

    • 3D Analytical Modeling of Rotational Eddy Current Speed Sensor 

      Author: Mirzaei M.; Ripka P.
      (IEEE Sensors Council, 2024)
      —The main goal of this paper is to present a novel 3D analytical method for precise and fast modeling of rotational eddy current speed sensors with cylindrical structures. An equivalent linearized model is developed using ...

    • AC/DC Current Transformer With Single Winding 

      Author: Ripka P.; Draxler K.; Styblíková R.
      (IEEE, 2014)
      AC/DC Current Transformer With Single Winding is a device which allows simultaneously measure AC and DC current using fluxgate effect

    • AMR Gradiometer for Mine Detection 

      Author: Vyhnánek J.; Janošek M.; Ripka P.
      (Elsevier Science, 2012)
      Anisotropic magnetoresistors (AMRs) are used to build an advanced mine detector. The sensing head involves a gradiometric pair of AMR sensors and a continuous-wave driven excitation coil, so the gradiometer is capable of ...

    • AMR Proximity Sensor With Inherent Demodulation 

      Author: Ripka P.; Vyhnánek J.; Janošek M.; Včelák J.
      (IEEE Sensors Council, 2014)
      Our novel position sensor is based on the combination of the eddy-current and permeability effects. The primary field is excited by a coil, but instead of induction coil, the sensing part uses anisotropic magnetoresistor ...

    • Analysis of Material Effect on Rail Impedance 

      Author: Mirzaei M.; Ripka P.
      (IEEE, 2018)
      In this paper, two different solid iron materials are used for two different size rails. The internal impedances, resistances and inductances of the rails are evaluated and analyzed with time harmonic and time stepping ...

    • The apparent permeability and the amplification factor of magnetic wires and wire arrays 

      Author: Ripka P.; Grim V.; Mirzaei M.
      (Elsevier, 2021)
      We have calculated and plotted the apparent permeability and the demagnetization factor of single magnetic wires. We have also confirmed the accuracy of the analytical formula for the conversion between the apparent ...

    • An Axial Airgap Eddy Current Speed Sensor 

      Author: Mirzaei M.; Grim V.; Ripka P.
      (IEEE Industrial Electronics Society, 2022)
      This paper presents a novel configuration of the eddy current speed sensor to measure the rotating speed of iron rods and shafts up to 3000 rpm. The proposed eddy current speed sensor has an axial airgap structure with ...

    • An axial flux eddy current sensor with perpendicular coils for speed measurement 

      Author: Mirzaei M.; Ripka P.; Grim V.; Hazdra Z.
      (Elsevier, 2024)
      This paper presents an axial flux eddy current sensor with a compact and simple structure for measuring the rotating speed of iron shafts. The sensor structure is optimized for high sensitivity with a novel configuration ...

    • C-Shape Busbar With Frequency Invariant Points for Wideband Current Measurement 

      Author: George N.; Ripka P.; Grim V.
      (IEEE Industrial Electronics Society, 2024)
      A yokeless busbar current transducer with frequency-invariant points is presented for the first time in this article. Existing rectangular busbar current transducers suffer from the frequency dependency issue due to the ...

    • Calibration of the 3D Coil System's Orthogonality 

      Author: Zikmund A.; Ripka P.
      (IEEE, 2013)
      Two methods were tested for calibration procedures of the 3D coil system which is used as a source part of the magnetic tracker. Precise magnetometer’s positions with respect to the coil system were used for determining ...

    • Co-Based Amorphous Material for Giant Magneto-Impendance and Fluxgate Sensing Cores 

      Author: Sarkar P.; Včelák J.; K Roy R.; K Panda A.; Mitra A.; Ripka P.
      (IEEE, 2015)
      Alloy composition (Co94Fe6)72.75Si12.25B13.25Cr1.75 was designed to develop nearly zero-magnetostrictive materials in the form of ribbons and wires to obtain suitable magnetic properties for use as giant magneto-impedance ...

    • Contactless measurement of electric current using magnetic sensors 

      Author: Ripka P.
      (Oldenbourg Verlag, 2019)
      We review recent advances in magnetic sensors for DC/AC current transducers, especially novel AMR sensors and integrated fluxgates, and we make critical comparison of their properties. Most contactless electric current ...

    • Contribution to the Ring-Core Fluxgate Theory 

      Author: Ripka P.
      (The Royal Swedisch Academy of Sciences, 1989)
      Existing theories for open-core fluxgate are not fitting experimental results in the case of ring-core sensors. Simple description based on transfer functions which takes into account the interaction between two half-cores ...

    • Crossfield response of industrial magnetic sensors 

      Author: Ripka P.; Vyhnánek J.; Chirtsov A.
      (IOS Press, 2017)
      Magnetic sensors used for non-destructive testing, metal detection and other applications are subjected to large perpendicular field. In this paper we show that the existing models describing the response of anisotropic ...

    • D. Hrakova, P. Ripka, A. Laposa, D. Novotny, J. Kroutil, V. Povolný, O. Kaman, P. Veverka 

      Author: Hrakova D.; Ripka P.; Laposa A.; Novotný D.; Kroutil J.; Povolný V.; Kaman O.; Veverka P.
      (Elsevier, 2022)
      Non-planar fluxgate sensors measuring the magnetic fields in the uT range are required for electric current, position, and torque transducers. We report the first sensor based on an inkjet-printed 17 mm diameter ring core. ...

    • DC current sensor using switching-mode excited in-situ current transformer 

      Author: Grim V.; Ripka P.; Bauer J.
      (Elsevier, 2020)
      DC current component in the power grid may cause gross measurement errors and lead to overheating of power transformers. We have previously developed method how to measure DC current using fluxgate effect in existing current ...

    • DC-Compensated Current Transformer 

      Author: Ripka P.; Draxler K.; Styblíková R.
      (Molecular Diversity Preservation International, 2016)
      Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC ...

    • Demagnetization of Current Transformers Using PWM Burden 

      Author: Bauer J.; Ripka P.; Draxler K.; Styblíková Renata
      (IEEE, 2015)
      Current transformers (CTs) show large errors when they are magnetized by dc current. This error can be reduced after proper demagnetization. One of the methods to demagnetize the CT is to increase the core flux by increasing ...

    • Design and modeling of a linear speed sensor with a flat type structure and air coils 

      Author: Mirzaei M.; Ripka P.; Chirtsov A.; Vyhnánek J.; Grim V.
      (Elsevier, 2020)
      This paper presents the design and modeling of a linear eddy current speed sensor with a flat type structure and an air coil configuration. The theory of the eddy current speed sensor is based on utilizing the speed component ...