Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

1099 results about "Magnetic orientation" patented technology

A magnetic orientation the same as that of Earth's current magnetic field. Magnetic orientations in rock that are opposite to the current orientation of Earth's magnetic field. A change in Earth's magnetic field in which the north magnetic pole becomes the south magnetic pole and vice versa.

Magnetic Field Sensor For Measuring A Direction Of A Magnetic Field In A Plane

A magnetic field sensor for measuring a direction of a magnetic field in a plane comprises a sensing structure comprising a ring-shaped well, a plurality of contacts of equal size placed at equal distance from each other along the ring-shaped well, and an electronic circuit comprising a plurality of electronic switches associated with the contacts of the sensing structure, a logic block for controlling the electronic switches, at least one current source, a means for measuring a difference between a first voltage and a second voltage, a timing circuit providing a control signal for controlling the logic block and providing a reference signal, wherein the logic block is adapted to close and open the electronic switches under the control of the control signal according to a predetermined scheme such that a predetermined number of contacts of the plurality of contacts form a vertical Hall element that is supplied with current from the at least one current source and that has two contacts connected to the means for measuring, and such that the vertical Hall element is moved in steps along the ring-shaped well, and a means for measuring a phase shift between the reference signal and an output signal of the voltage measuring means.
Owner:ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)

Electromagnetical ultrasonic thickness-measuring method

The invention discloses a method for detecting ferrous magnetic material thickness by utilizing electromagnetic ultrasound, and is characterized in that a magnet inside an electromagnetic ultrasound transducer takes a U-shaped permanent magnet, a coil takes a PCB double-layer coil that takes the shape of a Chinese character, 'Hui' and is positioned at an opening of the permanent magnet, and an effective lead part of the coil is parallel to the direction of a bias magnetic field. In thickness measurement, the electromagnetic ultrasound transducer is positioned on a detected object, high-frequency electric sinusoidal pulse current passes through the coil, according to the magnetostrictive effect, the detected object generates partial stretching deformation and oscillation, and consequently excites ultrasonic transverse wave and leads the ultrasonic transverse wave to spread downwards in a direction vertical to surfaces of the detected object. The ultrasonic wave is reflected by a lower surface of the detected object, and then the reflected wave is received by the coil. A received ultrasonic signal is collected and input into a computer after being amplified. If the ultrasonic wave spreading velocity in the detected object is v, and the spreading time is t, then the thickness of the detected object d is equal to a half of v multiplied by t. The method for detecting ferrous magnetic material thickness by realizing the thickness detection of ferrous magnetic materials, has the non-contact and couplant-free advantages, and can be used in high-temperature environment and for detecting materials with rough surfaces.
Owner:TSINGHUA UNIV

Method for determining initial position angle of rotor of permanent magnet synchronous motor

The invention relates to a method for determining an initial position angle of a rotor of a permanent magnet synchronous motor, which belongs to the field of motor control. The invention aims to solve the problems that a rotor detection method provided by a patent of a method and a device for detecting an initial position of a motor rotor in an alternating current servo system has complex logical decision and easy failure of detection. The method for determining the initial position angle of the rotor of the permanent magnet synchronous motor comprises the following steps: controlling the amplitude and the phase of the current of a d shaft and a q shaft under a two-phase synchronous rotating shaft system to further control the amplitude and the phase of the current of a three-phase stator under a three-phase stationary shaft system; controlling the rotation of the motor rotor under a given stator magnetic field; and according to a pulse signal fed back by an incremental encoder, making the direction of the given magnetic field gradually and circularly approach the actual position angle of the rotor until the direction of the given stator magnetic field corresponding to the current of the d shaft and the q shaft is coincident with the direction of a rotor magnetic field. The direction of a given stator current magnetic field is changed by 90 degrees, so that a torque vertical to the direction of the rotor magnetic field is generated on the rotor, and according to the rotating direction of the rotor, the initial position angle of the actual rotor is determined.
Owner:HARBIN INST OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products