Energized Movable Sensing Coil Magnetometers Patents (Class 324/256)
  • Patent number: 11243272
    Abstract: A magnetic field gradient sensor includes a support and a structure having at least a first and a second mobile element, at least one magnetic sensor, each magnetic sensor being mechanically secured to one of the first and/or second mobile elements so as to be able to apply a mechanical force to the structure in the presence of a magnetic field gradient, a coupler for coupling between the first and second mobile elements so that the structure can be moved in at least one balanced mechanical mode in the presence of a magnetic field gradient, and a sensor for measuring the movement of the structure at least in balanced mode.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: February 8, 2022
    Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
    Inventors: Guillaume Jourdan, Bertrand Delaet, Loic Joet
  • Patent number: 11126213
    Abstract: Systems and methods are disclosed for managing power supplied over an electric power grid from at least one power supply source. A coordinator manages communications between at least one server and the at least one power supply source, wherein the server is operable to initiate power commands, wherein the communications comprise an actual amount of power supply available for the electric power grid from the at least one power supply source, and wherein the at least one power supply source is operable to provide power supply to the electric power grid based on the power commands.
    Type: Grant
    Filed: September 27, 2019
    Date of Patent: September 21, 2021
    Assignee: CAUSAM ENTERPRISES, INC.
    Inventor: Joseph W. Forbes, Jr.
  • Patent number: 10637270
    Abstract: A battery charging circuit for charging a battery is provided. The battery charging circuit includes a control module and a charging mode adjusting module. The charging mode adjusting module adjusts a charging mode according to a voltage value or a current value or an internal resistor of the battery. The charging mode adjusting module includes a charging unit and a detecting unit. The charging unit provides a charging current or a charging voltage to charge the battery. The detecting unit is electrically connected to the charging unit to detect the voltage value or the current value or the internal resistor of the battery.
    Type: Grant
    Filed: April 26, 2019
    Date of Patent: April 28, 2020
    Assignee: ANPEC ELECTRONICS CORPORATION
    Inventor: Chih-Ning Chen
  • Patent number: 10429871
    Abstract: Systems and methods for managing power supplied over an electric power grid by an electric utility and/or other market participants to multiplicity of grid elements and devices for supply and/or load curtailment as supply, each of which having a Power Supply Value (PSV) associated with its energy consumption and/or reduction in consumption and/or supply, and wherein messaging is managed through a network by a Coordinator using IP messaging for communication with the grid elements and devices, with the energy management system (EMS), and with the utilities, market participants, and/or grid operators.
    Type: Grant
    Filed: February 6, 2017
    Date of Patent: October 1, 2019
    Assignee: CAUSAM ENERGY, INC.
    Inventor: Joseph W. Forbes, Jr.
  • Patent number: 9194919
    Abstract: An electric storage device includes an electric storage unit that includes one or a plurality of electric storage elements, a measurement unit that measures voltage, a current, and a temperature of the electric storage element, and a calculation unit that calculates internal resistance of the electric storage element based on the voltage, the current, and the temperature measured by the measurement unit. When a determination unit detects discontinuity of temporal variation of the calculated internal resistance, it is determined that the electric storage element has been exchanged. Since the electric storage element such as a lithium ion secondary battery has such a characteristic that the internal resistance increases as the number of use is increased, the exchange of batteries can be detected from the change in the internal resistance.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: November 24, 2015
    Assignee: Sony Corporation
    Inventor: Shinichi Uesaka
  • Publication number: 20150035526
    Abstract: A magnetic-field sensor, including: a die, a current generator in the die. The current generator generating a driving current. A Lorentz force transducer also in the die and being configured to obtain measurements of magnetic field based upon the Lorentz force is coupled to the current generator. The transducer having a resonance frequency. The current generator is such that the driving current has a non-zero frequency different from the resonance frequency.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 5, 2015
    Inventors: Giacomo Langfelder, Alessandro Tocchio, Dario Paci
  • Patent number: 8945469
    Abstract: A magnetic immunoassay system with a mechanism for compensating the direct current residual magnetic field in the vicinity of the specimen measurement position, in a direction perpendicular to the magnetic marker direction of magnetization for the measurement target. This invention reduces the effects of the magnetic field emitted from the unbound magnetic marker due to the residual magnetic field in the specimen solution and detects with high sensitivity the signal of the bound target magnetic marker. The magnetic field at the measurement position is regulated so as to intersect the direction of magnetization of the magnetic marker for the measurement target, in order to make the magnetization direction of the magnetic marker that is unbound due to residual magnetism or remanence in the sample solution, intersect the magnetization direction of the magnetic marker for the measurement target.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: February 3, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Akira Tsukamoto, Kazuo Saitoh
  • Patent number: 8907680
    Abstract: A voltage detector for detecting a voltage generated in a second resonant coil that is disposed to face a first resonant coil and that performs at least one of electric power transmission and electric power reception to and from the first resonant coil in a contactless manner by means of electromagnetic resonance includes: a first high-impedance element having one end connected to one end of the second resonant coil; a second high-impedance element having one end connected to the other end of the second resonant coil; a low-impedance element connected between the other end of the first high-impedance element and the other end of the second high-impedance element and having an impedance smaller than each of those of the first and second high-impedance elements; and an output terminal for outputting a signal associated with a voltage applied across the low-impedance element.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: December 9, 2014
    Assignees: Nippon Soken, Inc., Toyota Jidosha Kabushiki Kaisha
    Inventors: Hiroyuki Sakakibara, Shinji Ichikawa
  • Patent number: 8796979
    Abstract: Disclosed is an apparatus for driving a BLDC motor, the apparatus including: a BLDC motor having a single sensing coil therein; a position/speed calculation unit for calculating a current position and a current speed of a rotor by using voltages at both ends of the sensing coil; a control unit for comparing the current speed of the rotor calculated by the position/speed calculation unit with a command speed and then outputting a control signal through a Proportional Integral (PI) control; a motor driving unit for generating a PWM signal based on the current position of the rotor calculated by the position/speed calculation unit and the control signal output by the control unit; and a power device unit for controlling the BLDC motor according to the PWM signal generated by the motor driving unit.
    Type: Grant
    Filed: November 9, 2012
    Date of Patent: August 5, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventor: Jimin Oh
  • Publication number: 20140184215
    Abstract: An eddy current testing apparatus includes: an eddy current testing probe having an eddy current testing coil arranged on a bottom portion of a casing; a pressing mechanism configured to press the eddy current testing probe so that the bottom portion of the eddy current testing probe is placed in contact with a part of an inner wall surface of a slot formed in an object to be inspected; a carriage configured to mount the pressing mechanism and the eddy current testing probe, the carriage traveling in a depth direction of the slot; and an eddy current testing control device configured to control defect detection for the inner wall surface of the slot by acquiring a detected eddy current signal from the eddy current testing coil.
    Type: Application
    Filed: November 14, 2013
    Publication date: July 3, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Akira NISHIMIZU, Atsushi ISHIHARA, Jun MATSUMOTO, Takayuki KAWANAKA
  • Publication number: 20140077798
    Abstract: Two suspended masses are configured so as to be flowed by respective currents flowing in the magnetometer plane in mutually transversal directions and are capacitively coupled to lower electrodes. Mobile sensing electrodes are carried by the first suspended mass and are capacitively coupled to respective fixed sensing electrodes. The first suspended mass is configured so as to be mobile in a direction transversal to the plane in presence of a magnetic field having a component in a first horizontal direction. The second suspended mass is configured so as to be mobile in a direction transversal to the plane in presence of a magnetic field having a component in a second horizontal direction, and the first suspended mass is configured so as to be mobile in a direction parallel to the plane and transversal to the current flowing in the first suspended mass in presence of a magnetic field having a component in a vertical direction.
    Type: Application
    Filed: May 29, 2013
    Publication date: March 20, 2014
    Inventors: Lorenzo Baldo, Francesco Procopio, Sarah Zerbini
  • Patent number: 8664950
    Abstract: A method for measuring longitudinal bias magnetic field in a tunnel magnetoresistive sensor of a magnetic head, the method includes the steps of: applying an external longitudinal time-changing magnetic field onto the tunnel magnetoresistive sensor; determining a shield saturation value of the tunnel magnetoresistive sensor under the application of the external longitudinal time-changing magnetic field; applying an external transverse time-changing magnetic field and an external longitudinal DC magnetic field onto the tunnel magnetoresistive sensor; determining a plurality of different output amplitudes under the application of the external transverse time-changing magnetic field and the application of different field strength values of the external longitudinal DC magnetic field; plotting a graph according to the different output amplitudes and the different field strength values; and determining the strength of the longitudinal bias magnetic field according to the graph and the shield saturation value.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: March 4, 2014
    Assignee: SAE Magnetics (H.K.) Ltd.
    Inventors: Siuman Mok, Hokei Lam, Cheukwing Leung, Juren Ding, Rongkwang Ni, Wanyin Kwan, Cheukman Lui, Chiuming Lueng
  • Patent number: 8648590
    Abstract: An induction detecting type rotary encoder includes: a stator; a rotor configured to be rotated with respect to a rotary shaft; a first transmitting coil; a second transmitting coil; a first receiving coil; a second receiving coil; a first magnetic flux coupling body; and a second magnetic flux coupling body. The first transmitting coil is disposed between the first and second receiving coils. A distance between the second transmitting coil and the rotary shaft is larger than that of the second receiving coil and the rotary shaft. The first magnetic flux coupling body forms a first track for causing a periodic change for each rotation. The second magnetic flux coupling body forms a second track for causing a periodic change for each rotation. The second magnetic flux coupling body has a pattern of which an inner peripheral side is substantially continuous in a circumferential direction.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: February 11, 2014
    Assignee: Mitutoyo Corporation
    Inventor: Hirokazu Kobayashi
  • Patent number: 8575944
    Abstract: A primary device for inductive power transfer to a secondary device is disclosed. The primary device includes a primary coil, the primary device being configured to (i) operate in a first mode during which the primary coil transfers power through inductive coupling to the secondary device, and (ii) operate in a second mode during which a foreign object is detected. The primary device further includes a primary controller configured to operate the primary coil (i) using a first frequency during the first mode, and (ii) using a second frequency during the second mode. A method to detect a foreign object which is in proximity of an inductively coupled environment of a primary device is also disclosed.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: November 5, 2013
    Assignee: Robert Bosch GmbH
    Inventors: Hariharakumaran Dorairaj, Rajeev Kumar, Surabhi Ganguly
  • Patent number: 8508242
    Abstract: A rotary position sensor having a transmitter coil energized by a high frequency current source. A first receiver coil includes an even number N of loops wherein adjacent loops of the first receiver coil are oppositely wound. A second receiver coil also includes N loops where adjacent loops are oppositely wound. Furthermore, the second receiver coil is angularly offset from the first receiver coil by 180/N degrees. A noncircular coupler constructed of an electrically conductive material is rotatably mounted relative to the coils so that the coupler element overlies at least a portion of the first and second receiver coils. A circuit processes the output signals from the first and second receiver coils and generates an output signal representative of the rotational position of the coupler.
    Type: Grant
    Filed: January 24, 2011
    Date of Patent: August 13, 2013
    Assignee: KSR Technologies Co.
    Inventors: Lingmin Shao, Joong K. Lee, Ryan W. Elliott
  • Patent number: 8290572
    Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The navigational domain contains navigational magnetic energy and disturbing magnetic energy, and the field influencing object produces the disturbing magnetic energy in response to the navigational magnetic energy. The correction system includes a first transmitter for projecting into the navigational domain field energy in a first waveform sufficient to induce a first signal value in the sensing coil. The system also includes a second transmitter for projecting into the navigational domain field energy in a second waveform sufficient to induce a second signal value in the sensing coil. The system further includes a signal processor for receiving the first signal value and for receiving the second signal value to determine the effect of the electrically conductive object on the field sensor.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: October 16, 2012
    Assignee: Medtronic Navigation, Inc.
    Inventors: Michael A. Martinelli, Paul Kessman, Bradley A. Jascob
  • Patent number: 8098066
    Abstract: A magnetometric device for evaluating a physical parameter (D, K), comprising a circuit (1) which is sensitive to a magnetic field, a measurement circuit (2) and a magnetic field generator (3), the sensitive circuit (1) being subjected to a magnetic field which varies with the physical parameter to be measured and having an electrical characteristic which is evaluated by the measurement circuit and which varies as a function of the magnetic field. The field generator (3) is designed to reverse the polarity of the applied magnetic field, the evaluation of the physical parameter thus being able to be corrected of the parasitic influence of the terrestrial magnetic field.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: January 17, 2012
    Assignee: Michelin Recherche et Technique S.A.
    Inventors: Thomas Ledoux, Nathalie Levain, Denis Martin
  • Patent number: 7797032
    Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The system includes a first and second transmitter to create signals. A signal processor is able to process the created signals. The method can include determining interference and/or a correct signal based on the two signals. Also, a shield can be provided to limit transmission of selected fields.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: September 14, 2010
    Assignee: Medtronic Navigation, Inc.
    Inventors: Michael A. Martinelli, Paul Kessman, Brad Jascob
  • Publication number: 20070216407
    Abstract: A battery monitor apparatus and method for an automotive battery system including a battery for supplying power to in-vehicle electrical equipment and sensors for detecting battery voltage, the charge/discharge current and the battery temperature are disclosed. The capacitance and the internal actual resistance of the battery are calculated at the time of starting the engine. Further, the theoretical internal resistance of the battery corresponding to the ambient temperature and the battery open-circuit voltage during the stationary engine state are detected in advance. Based on the change in the battery open-circuit voltage, the battery change is provisionally determined. After that, battery change or degeneration can be determined based on battery capacitance, the actual and theoretical internal resistance values of the battery, the battery open-circuit voltage and the provisional battery change determination value.
    Type: Application
    Filed: February 27, 2007
    Publication date: September 20, 2007
    Applicant: FUJITSU TEN LIMITED
    Inventor: Kazuhi Yamaguchi
  • Patent number: 6836121
    Abstract: A power switching control device and methods for using the same to control a magnetic actuator within a power switching device are disclosed. The power switching control device uses a series of modulated current pulses to control a magnetic actuator within a power switching device. The power switching control device inputs a power signal and applies a series of modulated current pulses through the coil of the magnetic actuator in a first direction such that the actuator moves from a first position to a second position. Certain operating characteristics of a power switching device can be ascertained by analyzing the impedance of the magnetic actuator coil within the power switching device. The power switching device control device also has an improved energy management system therein. In this manner, the controller includes a voltage regulator that has the ability to switch between operating modes.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: December 28, 2004
    Assignee: ABB Inc.
    Inventors: Erskine R. Barbour, Carl J. LaPlace
  • Patent number: 6788053
    Abstract: A sensor coil is provided on a core which forms a magnetic circuit for driving a linear motor, and the core is excited by electrifying the sensor coil at a high frequency. The high-frequency excitation is carried out in such a manner that the sensor coil is not magnetically saturated, and an eddy current is generated in the core. The impedance of the sensor coil is detected in this state and the quantity of a magnetic flux generated in the core constituting the magnetic circuit is detected on the basis of the impedance. Thus, the influence on the magnetic circuit itself is reduced and higher accuracy, miniaturization and lower power consumption are realized.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: September 7, 2004
    Assignee: Sony Precision Technology Inc.
    Inventors: Yasuo Nekado, Masaaki Kusumi, Ken Onoe
  • Patent number: 6549800
    Abstract: The systems and methods of the present invention provide for MRI probes adapted for insertion into a plurality of body orifices, in order to evaluate the anatomy of proximate anatomic structures, to diagnose abnormalities thereof and to treat the diagnosed abnormalities. MRI probes are described that are suitable for use in the mediastinum, in the pancreaticohepaticobiliary system, in the tracheobronchopulmonary system, in the head and neck, in the genitourinary system, the gastrointestinal system, the vascular system, and in the evaluation, diagnosis and treatment of internal fluid collections.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: April 15, 2003
    Assignee: Johns Hopkins Unversity School of Medicine
    Inventors: Ergin Atalar, Paul A. Bottomley, Elias Zerhouin, Henry Halperin, Elliot McVeigh, Albert C. Lardo
  • Patent number: 6123902
    Abstract: An apparatus for the qualitative and/or quantitative measurement of analytes, in particular in biological samples by means of receptor ligand binding and having a magnetizing device for the production of a magnetic field at the location of the sample and with a detection device for measurement of magnetic properties of the sample is characterized in that the magnetizing device is spatially disposed with respect to the detection device in such a fashion that the magnetic field produced by the magnetization device at the location of the magnetization is attenuated by at least a factor of 10, and preferentially by a factor of 1000 or more, at the location occupied by the sample during the measurement, or in that a switching device is provided for which, throughout a predetermined time duration and in particular during the measurement phase of the detection device can switch-off the magnetic field of the magnetizing device at the location of the sample.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: September 26, 2000
    Assignee: Institut Fuer Diagnostik-Forschung an Der Freien Universitaet Berlin
    Inventors: Hans Koch, Hartmut Matz, Roman Kotitz, Dietmar Drung, Lutz Trahms, Werner Weitschies, Wolfhard Semmler
  • Patent number: 6064201
    Abstract: Small metallic patches embedded in a mainly non-metallic surface may be detected and mapped by placing a wire coil at the free end of a cantilever, with a fine tip made of a ferro-magnetic material located at its center. An alternating current is passed through the coil so that when it is near a metallic patch eddy currents are induced in the patch. These produce a small magnetic moment in the patch which pulls the tip towards the surface. This movement of the tip is detected by observing a light beam that is reflected off the surface of the cantilever. By plotting the output of a photodetector, sensistive to small changes in the reflected beam's position, as a function of the tip's location over the surface, a map of the metallic patches is produced.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: May 16, 2000
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Cher Liang Randall Cha, Hao Gong, Eng Fong Chor, Lap Chan
  • Patent number: 5731703
    Abstract: A micromechanical D'Arsonval magnetometer for sensing magnetic fields at low frequency with high sensitivity for operation near the resonant frequency of a micromechanical structure comprising a movable proof mass supported by torsion flexures, a conductive winding formed on the movable proof mass, at least one bridge electrode spanning the movable proof mass, a source for electrically biasing the movable proof mass relative to the bridge electrode(s), and a drive for electrically driving the conductive winding. Magnetic fields in the plane of the proof mass perpendicular to an axis of rotation formed by the torsion flexures interact with current passing through the conductive winding so as to torque the proof mass about the axis of rotation, whereby the resulting rotation is sensed through capacitors formed between the proof mass and the bridge electrode(s). The present invention micromechanical D'Arsonval magnetometer can be operated either open or closed loop.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: March 24, 1998
    Assignee: The Charles Stark Draper Laboratory, Inc.
    Inventors: Jonathan J. Bernstein, Marc S. Weinberg
  • Patent number: 5548279
    Abstract: A method and apparatus for detecting power lines including a pickup coil for detecting the magnetic field generated by the current conducted by a power line and for producing a sense current in response to the detected magnetic field, a gyrator circuit for generating a sense voltage in response to the sense current and tuning means for producing an output voltage in response to the sense voltage such that a power line can be detected thereby. The tuning means also tunes the power line detecting apparatus to the predetermined frequency of the current conducted by the power lines. The power line detecting method and apparatus also preferably analyzes the magnitude and frequency of the output voltage produced by the tuning means so as to distinguish output voltages generated in response to the magnetic fields produced by power lines from those generated by extraneous electromagnetic noise.
    Type: Grant
    Filed: July 22, 1994
    Date of Patent: August 20, 1996
    Assignee: McDonnell Douglas Corporation
    Inventor: Robert B. Gaines
  • Patent number: 5541507
    Abstract: A magnet position detector, particularly for implantable medical devices, has a resiliently supported coil, a current source delivering a current to the coil and a detecting device for detecting the movement of the coil in a magnetic field when fed with an electric current from the current source. The coil has a core with a non-linear B-H curve and the current source is a pulse source delivering current pulses with at least one positive and one negative side. The detecting device detects the movements of the coil in opposite directions respectively excited by differentiated signals respectively corresponding to the leading and trailing edges and permits the magnitudes of the respective, oppositely directed movements to be compared to each other, thereby indicating the position of a source of the magnetic field, relative to the coil, to be determined.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: July 30, 1996
    Assignee: Pacesetter AB
    Inventor: Christer Ekwall
  • Patent number: 5424642
    Abstract: A magnetic field detector, particularly for implantable medical apparatuses, has a coil mounted at the free end of a resilient member fixed at its opposite end portion, and a detecting device for detecting, as a measure of a magnetic field, the movement of the coil in the field when fed with an electric current from a controllable current source. The resilient member is bent to form at least two shanks interconnected at one end. The coil is mounted at the free end of one of the shanks and the resilient member is fixed at the free end portion of the other shank.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: June 13, 1995
    Assignee: Siemens Aktiengesellschaft
    Inventor: Christer Ekwall
  • Patent number: 5387863
    Abstract: A synthetic array comprising a moving magnetic sensor that provides a signal representative of an array of magnetic sensors is coupled to a digital signal processor is used to break a magnetic dipole field into its components, and a magnetic signature of the present magnetic field is created. Predicted dipole signatures are precomputed for multiple magnetic orientations of the dipole at each of a plurality of range locations, expressed in terms of Anderson functions, which are a set of equations that decompose the magnetic field in each of the magnetic response locations, and are stored in a lookup table for reference. Input data measured by the moving synthetic array are processed and each magnetic value is predicted to process against background noise. A long term time average consistent with the relative motion of the dipole is computed using bandpass filtering of the signals from the synthetic array.
    Type: Grant
    Filed: April 14, 1992
    Date of Patent: February 7, 1995
    Assignee: Hughes Aircraft Company
    Inventors: Allen K. Lo, Wilbur W. Eaton, Jr., Ben R. Breed
  • Patent number: 5309096
    Abstract: In a known magnetic field detector, an electrical coil (8) is secured to a motion-sensitive, for example piezoelectric sensor (3); this electrical coil is charged with an electrical current for detecting the magnetic field with the sensor (3) and an evaluation means (14) which follows thereupon. In order to also be able to employ the magnetic field detector given arrangement thereof in an implantable medical device as activity sensor for the physical activity of a patient, the current charging of the coil (8) can be switched on and off with a control signal (21), whereby the control signal (21) is utilized for characterizing the sensor signal as an activity signal corresponding to the physical activity or as a detection signal that detects a magnetic field.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: May 3, 1994
    Assignee: Siemens Aktiengesellschaft
    Inventor: Kurt Hoegnelid
  • Patent number: 4887032
    Abstract: A vibration type sensor can make a noncontacting measurement of position or sense the passage of an object past a point. The sensor has a coil of wire placed on a vibrating structure. A power supply causes current to be passed through the coil at the resonant frequency of the vibrating structure. As an object with an attached magnet approaches the coil, a force is exerted on the current carrying coil thereby exciting the structure at its resonant vibrational frequency. A piezoelectric bimorph is attached to the structure so that it flexes with the structure producing an emf output proportional to the vibrational amplitude. As the object moves, the field strength at the coil, the amplitude of the vibration and the induced emf change. The latter quantity is used to sense the motion of the object.
    Type: Grant
    Filed: May 2, 1988
    Date of Patent: December 12, 1989
    Assignee: Ford Motor Company
    Inventor: Robert E. Hetrick
  • Patent number: 4730263
    Abstract: A method and device for measuring peak gamma radiation is provided wherein the method includes the steps of determining a minimum and maximum number of counts within a preselected multiple channel energy spectrum measurement range, determining a channel having approximately one-half the number of maximum counts, determining a channel representing a background energy, computing a peak energy centroid channel, computing a channel to energy conversion factor and recomputing the boundry channels for the preselected multiple channel energy spectrum measurement range.
    Type: Grant
    Filed: March 4, 1985
    Date of Patent: March 8, 1988
    Assignee: Gearhart Industries, Inc.
    Inventor: Gary L. Mathis
  • Patent number: 4523147
    Abstract: A fine balancing three-coil type gradiometer, comprising a support member for the coils which consists of two elements, the first of which bears the central coil and one of the end coils, while the second supports the other coil and is arranged to controllably cause the micrometric axial displacement of the element itself with respect to the other one, in order to vary the distance between the planes of the coils and to achieve the desired balancing.
    Type: Grant
    Filed: July 28, 1982
    Date of Patent: June 11, 1985
    Assignee: Consiglio Nazionale Delle Ricerche
    Inventors: Silvano D'Angelo, Ivo Modena, Gian L. Romani
  • Patent number: 4506221
    Abstract: A dual-axis magnetometer employs an electromagnet mounted by bender arms within a housing to permit pivotal vibration of the electromagnet with respect to the housing. The electromagnet is driven by an alternating current that causes it to vibrate in the presence of an external magnetic field having a component in a plane perpendicular to the axis of the electromagnet. Output signals are provided at conductors on opposite surfaces of the benders. By observing the relative magnitudes of the output signals and the relationships of their phases with that of the excitation signal, it is possible to determine the direction of that component of the external magnetic field that lies in a plane perpendicular to the electromagnet axis.
    Type: Grant
    Filed: June 28, 1982
    Date of Patent: March 19, 1985
    Assignee: Sanders Associates, Inc.
    Inventor: Paul F. Hayner