Now showing items 1-19 of 19

    • Advances in Magnetic Field Sensors 

      Author: Ripka, Pavel; Janošek, Michal
      (IEEE, 2010-06)
      The most important milestone in the field of magnetic sensors was when AMR sensors started to replace Hall sensors in many applications where the greater sensitivity of AMRs was an advantage. GMR and SDT sensors finally ...
    • Busbar current transducer with suppression of external fields and gradients 

      Author: Ripka, Pavel; Chirtsov, Andrey
      (IEEE, 2018)
    • Crossfield Sensitivity in AMR Sensors 

      Author: Ripka, Pavel; Janošek, Michal; Butta, Mattia
      (IEEE, 2009-10)
      We discuss the origin of the crossfield sensitivity of AMR sensors, the way how this error may influence the performance of an AMR compass and methods for its correction. Finally, we confirm the simple formulas experimentally. ...
    • Current Sensor in PCB Technology 

      Author: Ripka, Pavel; Kubík, Jan; Duffy, Maeve; Hurley, William Gerard; O’Reilly, Stephen
      (IEEE, 2005-06)
      A novel DC/AC current sensor works on the fluxgate principle. The core in the form of a 7/10-mm ring made of electrodeposited permalloy is sandwiched in the middle of a printed circuit board (PCB), whereas the sensor ...
    • Double-Core GMI Current Sensor 

      Author: Malátek, Michal; Ripka, Pavel; Kraus, Luděk
      (IEEE, 2005-10)
      A novel design of the giant magnetoimpedance contactless current sensor is presented. A double-core structure is used in order to improve the temperature stability. The temperature coefficient of sensitivity and offset ...
    • The effect of conductor permeability on electric current transducers 

      Author: Mirzaei, Mehran; Ripka, Pavel; Chirtsov, Andrey; Kašpar, Petr; Vyhnánek, Jan
      (American Institute of Physics, 2018)
      In this paper, experimental works and theoretical analysis are presented to analyze the influence of the conductor permeability on the precision of yokeless current sensors. The results of finite-element method (FEM) fit ...
    • Excitation and Temperature Stability of PCB Fluxgate Sensor 

      Author: Tipek, Alois; O’Donnell, Terence; Ripka, Pavel; Kubík, Jan
      (IEEE, 2005-12)
      Printed circuit board (PCB) integrated inductors have been adapted for operation as fluxgate sensors. A ring core is made from an electrodeposited permalloy thin film and is sandwiched between the layers of the PCB. The ...
    • Fluxgate sensor with increased homogeneity 

      Author: Ripka, Pavel; Jireš, František; Macháček, Milan
      (IEEE, 1990-09)
      Several types of fluxgate sensors were developed for measuring microvariations of the earth's magnetic field. Sensor cores were produced by etching, leading to better geometric homogeneity and long-term stability. This ...
    • Fluxgate: Tuned vs. Untuned Output 

      Author: Ripka, Pavel; Billingsley, S.W.
      (IEEE, 1998-07)
      Fluxgate voltage output contains information about the measured DC magnetic field in amplitude of even harmonic components. Tuning the sensor output causes the concentration of output energy to specific harmonics (usually ...
    • Giant Magnetoimpedance Sensors 

      Author: Hauser, Hans; Kraus, Luděk; Ripka, Pavel
      (IEEE, 2001-06)
      Magnetoinductance and giant magnetoimpedance (GMI) sensors have greatly benefited from the development of amorphous wires. These soft ferromagnetic substances exhibit exquisite sensitivity (in the nT range) and wide bandwidth ...
    • Inductance position sensor for pneumatic cylinder 

      Author: Ripka, Pavel; Chirtsov, Andrey; Mirzaei, Mehran; Vyhnánek, Jan
      (American Institute of Physics, 2018)
      The position of the piston in pneumatic cylinder with aluminum wall can be measured by external inductance sensor without modifications of the aluminum piston and massive iron piston rod. For frequencies below 20 Hz the ...
    • Linearity of Pulse Excited Coil-Less Fluxgate 

      Author: Butta, Mattia; Ripka, Pavel
      (IEEE, 2009-10)
      In this paper, we study the open-loop linearity of pulse excited coil-less fluxgate. Narrow current pulses can be used instead of classical sinewave for the excitation of the coil-less fluxgate. This method has shown several ...
    • Low-Power Printed Circuit Board Fluxgate Sensor 

      Author: Kubík, Jan; Pavel, Lukáš; Ripka, Pavel; Kašpar, Petr
      (IEEE, 2007-02)
      A new printed circuit board flat fluxgate sensor with integrated coils and amorphous alloy core was developed and its excitation parameters optimized for low-power consumption. The power consumption achieved with 10 kHz, ...
    • Multiple Layer Scanning in Magnetopneumography 

      Author: Tomek, Jiří; Platil, Antonín; Ripka, Pavel
      (IEEE, 2009-04)
      In magnetopneumography (MPG), we scan weak remanent magnetic fields (in the range of nT) of ferromagnetic dust deposited in the lungs of affected workers. This is carried out in an unshielded lab. Variations of the background ...
    • Off-Center Error Correction of AMR Yokeless Current Transducer 

      Author: Mlejnek, Pavel; Ripka, Pavel
      (Hindawi Publishing Corporation, 2017)
      We present a method of calibration and error correction of the AMR yokeless current transducer consisting of a circular array of eight anisotropic magnetoresistors (AMR) with one feedback compensation loop. The main sources ...
    • Pulse Excitation of Micro-Fluxgate Sensors 

      Author: Ripka, Pavel; Choi, San On; Tipek, Alois; Kawahito, Shoji; Ishida, Makoto
      (IEEE, 2001-07)
      Miniature fluxgate sensors with symmetrical closed core elements on both sides of the planar coils were manufactured using standard microtechnology. The new sensors have shown substantial improvement over the standard ...
    • Sensitivity and Noise of Wire-Core Transverse Fluxgate 

      Author: Ripka, Pavel; Butta, Mattia; Jie, Fan; Li, Xiaoping
      (IEEE, 2010-02)
      Fluxgate sensors with cores made of amorphous microwire have low sensitivity due to the small cross-sectional area of the wire. Previous studies with multiwire cores have shown nonlinear increase of sensitivity with number ...
    • Single-core fluxgate gradiometer with simultaneous gradient and homogeneous feedback operation 

      Author: Janošek, Michal; Ripka, Pavel; Ludwig, Frank; Schilling, Meinhard
      (American Institute of Physics, 2012-03-06)
      A novel configuration of a single-core gradiometer, utilizing both homogeneous and gradient feedback operation, is presented. The fluxgate gradiometer comprises of a standard pick-up/ feedback coil and an additional gradient ...
    • Two-Domain Model for Orthogonal Fluxgate 

      Author: Butta, Mattia; Ripka, Pavel
      (IEEE, 2008-11)
      In this paper a new model for orthogonal fluxgate is presented. A first attempt to explain the working principle of the orthogonal fluxgates was done in the 1970's. We show that this model does not work well on recently ...