Patents Assigned to LEM INTELLECTUAL PROPERTY SA
  • Publication number: 20140253100
    Abstract: An electrical current transducer comprising a housing, at least one magnetic core comprising an air gap and defining a central passage configured to receive a primary conductor carrying a primary current to be measured through the central passage, a magnetic field detector positioned at least partially in the air gap, and a grounding element. A lateral surface of the magnetic core is positioned against the grounding element without direct fixed attachment between the magnetic core and the grounding element, and the grounding element overlaps the magnetic core to an extent configured to ensure that a capacitive coupling (C3) between the magnetic core and the grounding element is greater than a capacitive coupling (C2) between the magnetic core and the magnetic field detector.
    Type: Application
    Filed: July 12, 2012
    Publication date: September 11, 2014
    Applicant: LEM INTELLECTUAL PROPERTY SA
    Inventors: Gèrard Lepine, Vinh Tho Vo, Arnaud Labbe
  • Patent number: 8797020
    Abstract: Electrical current sensor comprising a measuring circuit (6) and an inductor (4) for measuring a primary current IP flowing in a primary conductor (2), the inductor comprising a saturable magnetic core (10) made of a highly permeable magnetic material and a secondary coil (12) for carrying an alternating excitation i configured to alternatingly saturate the magnetic core, the coil being connected to the measuring circuit. The measuring circuit is configured to supply a positive or negative voltage to the inductor, to switch off the voltage when a condition signalling saturation is reached, to measure the time to saturation t1 in one direction and the time to saturation t2 in the other direction of the magnetic core and determine therefrom a value of the primary current for small current amplitudes, the measuring circuit being further configured for evaluating the average value of the excitation current i and determining therefrom the value of the primary current for large currents.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: August 5, 2014
    Assignee: LEM Intellectual Property SA
    Inventors: Wolfram Teppan, Davide Azzoni
  • Patent number: 8618796
    Abstract: Closed-loop current sensor comprising a magnetic circuit, a magnetic field sensor, and a compensation circuit configured to generate a magnetic field opposing a magnetic field created by an electrical current to be measured flowing in one or more primary conductors (10) extending through a central opening (38) of the magnetic circuit. The magnetic circuit comprises a magnetic core (4) made of at least two core parts (28a, 28b) assembled together to form a substantially closed magnetic circuit, wherein a second branch (32) of the magnetic circuit comprises inner (40a, 40b) and outer (42a, 42b) wall portions joined by one or more lateral wall portions (46a, 46b, 46a?, 46b?) at least partially surrounding a cavity portion (44) receiving the magnetic field sensor (8) therein, the lateral and outer wall portions extending from one or both lateral edges of the inner wall portion.
    Type: Grant
    Filed: January 21, 2009
    Date of Patent: December 31, 2013
    Assignee: LEM Intellectual Property SA
    Inventors: Wolfram Teppan, Dominik Schlafli
  • Publication number: 20130241534
    Abstract: A closed-loop current transducer for measuring a current (Ip) flowing in a primary conductor (5), the transducer powered by series connected voltage supplies (V_H, V_L) and comprising a magnetic field detector (WS2), a signal processing circuit including an amplifier circuit (1, 2) connected to the magnetic field detector, and a compensation winding (WS1) connected to the amplifier circuit and configured to generate an opposing magnetic field seeking to cancel a magnetic field generated by the current flowing in the primary conductor. The amplifier circuit comprises a first switched mode power stage configured to drive the magnetic field generator, and a second switched mode power stage (2) configured to balance the currents of the voltage supplies.
    Type: Application
    Filed: September 20, 2011
    Publication date: September 19, 2013
    Applicant: LEM INTELLECTUAL PROPERTY SA
    Inventor: Marc Schaerrer
  • Patent number: 8519699
    Abstract: An electrical current sensor is disclosed having conducting coil portion and an insulating body portion, the conducting coil portion comprising a coil portion with one or more helical windings made of a wire conductor and encircling a central cavity. Adjacent windings are separated by a dielectrically effective gap, wherein the insulating body portion comprises a dielectric spacer comprising a helical gap maintaining protuberance configured for insertion in the central cavity of the windings such that the gap maintaining protuberance is at least partially inserted in the gap between windings.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: August 27, 2013
    Assignee: LEM Intellectual Property SA
    Inventors: Mikio Kurosawa, Takashi Kato
  • Publication number: 20130154629
    Abstract: Toroidal fluxgate current transducer comprising a ring shaped fluxgate sensing unit (6) comprising a ring-shaped support (40), a saturable magnetic core (38) mounted on the support (40), an excitation coil (44) wound around the support and saturable core and a magnetic shell (32) mounted around the excitation coil, ring-shaped support and saturable core. The support is ringed-shape and comprises terminals (50,48) fixed to the support, a first pair of said terminals connected to ends of the excitation coil, and a second pair of said terminals connected to ends of a secondary coil of the current transducer.
    Type: Application
    Filed: August 19, 2011
    Publication date: June 20, 2013
    Applicant: LEM INTELLECTUAL PROPERTY SA
    Inventors: Claude Gudel, Benjamin Marcoz, Bernard Richard, Gérard Gery
  • Publication number: 20130099782
    Abstract: Integrated circuit Hall sensor system comprising a plurality of elementary blocks (EB), each elementary block including a Hall cell (4), a differential pair (8) of an input stage of a Differential Difference Amplifier (DDA), and terminals (12a, 12b), wherein the terminals (12a, 12b) are placed laterally on opposing outer sides of each elementary block parallel to a Y axis and the plurality of elementary blocks are arranged in a juxtaposed manner to form at least one row (6a, 6b) extending along an X axis orthogonal to the Y axis and interconnected by the terminals.
    Type: Application
    Filed: July 1, 2011
    Publication date: April 25, 2013
    Applicant: LEM INTELLECTUAL PROPERTY SA
    Inventors: Pavel Kejik, Serge Reymond
  • Publication number: 20130093412
    Abstract: Magnetic field sensor including a magnetic field sensing circuit (2) comprising a reference magnetic field generator (8) and a magnetic field sensing cell (6), and a signal processing circuit (4) connected to the output of the magnetic field sensing cell and comprising a demodulator circuit and a gain correction feedback circuit (30, 28, 47) for correcting error fluctuations in the transfer characteristic of the magnetic field sensor. The sensor further comprises a reference current generator (3) configured to generate a reference current I ref, the reference current generator connected to the magnetic field sensing circuit (2) configured for generating the reference magnetic field B ref and to the gain correction feedback circuit configured for providing a reference signal (yref) to which an output signal of the demodulator circuit may be compared.
    Type: Application
    Filed: June 27, 2011
    Publication date: April 18, 2013
    Applicant: LEM INTELLECTUAL PROPERTY SA
    Inventors: Giovanni Maria Anelli, Marc Pastre, Andrea Ajbl, Maher Kayal
  • Patent number: D684927
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: June 25, 2013
    Assignee: LEM Intellectual Property SA
    Inventor: Philippe Sage
  • Patent number: D685325
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: July 2, 2013
    Assignee: LEM Intellectual Property SA
    Inventor: Takayuki Hayashi
  • Patent number: D685734
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: July 9, 2013
    Assignee: LEM Intellectual Property SA
    Inventor: Philippe Sage
  • Patent number: D686156
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: July 16, 2013
    Assignee: LEM Intellectual Property SA
    Inventor: Nanshan Ye
  • Patent number: D686989
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: July 30, 2013
    Assignee: LEM Intellectual Property SA
    Inventor: Takayuki Hayashi
  • Patent number: D688626
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: August 27, 2013
    Assignee: LEM Intellectual Property SA
    Inventor: Nanshan Ye
  • Patent number: D742842
    Type: Grant
    Filed: September 23, 2014
    Date of Patent: November 10, 2015
    Assignee: LEM INTELLECTUAL PROPERTY SA
    Inventor: Takayuki Hayashi