Abstract: A sensing apparatus includes a fluxgate module which outputs an analog signal corresponding to terrestrial magnetism using a fluxgate having a magnetic substance core and a driving coil, and an analog-to-digital (A/D) converter which converts an analog signal output from the fluxgate module into a digital signal. The fluxgate module includes first and second current amplifiers for exciting the magnetic substance core by applying pulses to first and second ends of the driving coil, and a pulse restricting part for driving the first and second current amplifiers to apply the pulses and for stopping driving the first and second current amplifiers when converting the analog signal into the digital signal is completed.

Abstract: A magnetic detection device includes a mode switching section capable of switching over a 1-output mode in which a (+) magnetic-field detected signal and a (?) magnetic-field detected signal are both outputted from a first external output terminal, and a 2-output mode in which the (+) magnetic-field detected signal and the (?) magnetic-field detected signal are outputted respectively from the first external output terminal and a second external output terminal. The provision of the mode switching section in an integrated circuit makes it possible to perform mode selection, in particular to realize the mode selection with a simple circuit configuration resulting in a reduction of the production cost.

Abstract: An array of three-axis magnetometers used for dynamic magnetic anomaly compensation are located at the corners of a parallelopiped, with pairs of magnetometer outputs used to derive a magnetic anomaly gradient vector used to compensate a compass and/or the output of a gyroscope in an inertial management unit. The system may be used in a neutrally buoyant remotely operated vehicle to permit ascertaining of course and position in the absence of surface control signals.

Abstract: A magnetic type angle sensor includes a rotary body having a first sensed part provided on a circumferential surface thereof with projecting parts and recessed parts at equal intervals in a circumferential direction thereof and a second sensed part provided on a circumferential surface thereof with a projecting parts at just one location, and a magnetic sensing device for sensing a change in a magnetic field along with rotation of the rotary body. The rotary body is formed with a plurality of projecting parts and recessed parts in a gear shape by gear cutting on the circumferential surface, then is cut with a groove at the center thereof in the axial direction thereof and has all projecting parts in a half section in the axial direction thereof cut off except for one.

Abstract: To provide a low-cost magnetic detection circuit, in which the differential detection function accomplished by outputting differential signals may not be lost, and which may be hardly affected by temperature fluctuations and may be resistant to noise, and in which the number of magnetic detection elements may be reduced, and to provide an encoder, the costs of which may be further reduced by using such a magnetic detection circuit for the multi-revolution detection part, etc., a magnetic detection circuit includes a bridge circuit formed by two bridge sections between the current-source terminal and the grounding terminal. The first bridge section and the second bridge section of the bridge circuit include magnetic detection elements MR1, MR2, respectively, and, viewed from the output-signal output points, the magnetic detection elements MR1, MR2 in the two bridge sections are arranged on only one of the sides that include the current-source side and the grounding-terminal side.

Abstract: An instrument is disclosed for measuring resistivity of Earth formations from within a conductive pipe inside a wellbore drilled through the formations. The instrument includes a plurality of housings connected end to end and adapted to traverse the wellbore. At least one electrode is disposed on each housing. Each electrode is adapted to be placed in electrical contact with the inside of the pipe. The instrument includes a source of electrical current, a digital voltage measuring circuit and a switch. The switch is arranged to connect the source of electrical current between one of the electrodes and a current return at a selectable one of the top of the pipe and a location near the Earth's surface at a selected distance from the top of the pipe, and to connect selected pairs of the electrodes to the digital voltage measuring circuit. The pairs are selected to make voltage measurements corresponding to selected axial distances and selected lateral depths in the Earth formations.

Abstract: A loop antenna useful, for example, in investigation of earth formations. Embodiments of the invention provide a loop antenna circuit comprising a loop antenna disposed to generate, in response to an electromagnetic wave, a pick-up signal on an output node. Loop antenna circuit further includes a tuning network coupled to the loop antenna. The tuning network is disposed to provide simultaneous tuning at a plurality of interrogation frequencies. Further embodiments include a preamplifier circuit coupled to the loop antenna. The preamplifier circuit is disposed to receive the pick-up signal on an input node and provide a high impedance load to the loop antenna for a first of the plurality of interrogation frequencies to reduce the secondary radiation from the loop antenna to below a predetermined value at the said first interrogation frequency.

Abstract: A micro-machining method of manufacturing a micro fluxgate sensor manufactured having an amorphous magnetic core includes forming lower coils of an excitation coil and a magnetic field detecting coil on a wafer, depositing a first insulating layer on the lower coils and forming an amorphous magnetic core, depositing a second insulating layer on the amorphous magnetic core and forming upper coils connected to the lower coils to complete the excitation coil and the magnetic field detecting coil, and covering the excitation coil and the magnetic field detecting coil with a protective film, and etching the protective film to expose a portion of the excitation coil and magnetic field detecting coil, thereby forming a pad.

Abstract: A rotary position sensor apparatus includes a magnet having a surface and a plurality of Hall components placed in association with the surface of the magnet. The Hall components are located on a neutral axis of the magnet thereby forming a rotary position sensor apparatus having an enhanced linearity, a reduced calibration time and a compact size. A printed circuit board (PCB) can also be provided and the Hall components mounted to the PCB. The magnet preferably possesses a rectangular shape, but other shapes may be implemented depending upon design considerations.

Abstract: A magnetic field measuring device, equipped with a fluxgate magnetometer, the device including a magnetic sensor equipped with at least one magnetic core and a plurality of windings, and configured to deliver at least one output signal, pulse generating means for emitting at least one excitation signal at the input of the magnetic sensor, in the form of a succession of excitation pulses, one excitation pulse of the excitation pulses having a duration at least 50 times less than a period of the at least one excitation signal, sampling means for sampling the output signal of the magnetic sensor, and means for, following the emission of at least one excitation pulse of the succession of excitation pulses and during the duration of the at least one excitation pulse, triggering at least one acquisition of the output signal of the magnetic sensor by the sampling means.

Abstract: A rotational position sensor having a compact and simple structure, in which a magnetic surface can be formed to have a more accurate shape, and an electronically controlled throttle device for an internal combustion engine, which employs the rotational position sensor. The rotational position sensor comprises a pair of substantially half disk-shaped magnetic cores disposed in an opposed relation to each other with a magnetic sensitive device interposed therebetween, a pair of substantially arc-shaped magnetic cores disposed in an opposed relation to each other along outer peripheries of the half disk-shaped magnetic cores, and a permanent magnet fixed in contact with at least one of the arc-shaped magnetic cores. Magnetic flux generating from the permanent magnet flows successively through one of the arc-shaped magnetic cores, the half disk-shaped magnetic cores, and the other of the arc-shaped magnetic cores, followed by returning to the permanent magnet.

Abstract: An underground digital locating system includes a receiver capable of acquiring a signal produced by an underground object and displaying a digital representation of the orientation of underground object and of its depth. The system includes a carrying case for the digital locating receiver, the carrying case further including a transmitter for energizing underground objects to emit a magnetic field. A method of locating an underground object using the described system is also disclosed, as well as methods of measuring a flux field and translating a flux field signal of an underground object into a visual representation of the underground object on the display screen of the locating receiver.

Abstract: A printed circuit board integrated with a two-axis fluxgate sensor includes a first soft magnetic core formed lengthwise in a first axial direction, a first excitation coil formed of a metal film and wound around the first soft magnetic core, a first pick-up coil formed of a metal film and wound around the first soft magnetic core and the first excitation coil, a second soft magnetic core formed lengthwise in a second axial direction, the second axial direction being perpendicular to the first axial direction, a second excitation coil formed of a metal film and wound around the second soft magnetic core, a second pick-up coil formed of a metal film and wound around the second soft magnetic core and the second excitation coil, and a pad for establishing conductivity between the first and second excitation coils and the first and second pick-up coils and an external circuit.

Abstract: An electric current perturbation probe includes at least one driver coil and at least one receiver. The at least one driver coil produces an omni-directional magnetic field. The at least one receiver is decoupled from the omni-directional magnetic field. In one example, the at least one driver coil includes a first driver coil that defines a first effective coil axis which is positioned orthogonally to a second effective coil axis of a second driver coil. The first driver coil is provided with a first electrical excitation signal which is phase shifted by 90 degrees from a second electrical excitation signal used to drive the second driver coil.

Abstract: This invention concerns a method of making airborne geophysical measurements. Such measurements may be made from fixed or moving wing airplanes or dirigibles. The method comprises the following steps: taking first real time measurements from one, or more, geophysical instruments mounted in an aircraft to produce geophysical data related to the ground below that instrument. Taking second real time measurements from navigation and mapping instruments associated with or carried by the aircraft. Computing a background response of each geophysical instrument using the second real time measurements to take account of its time varying altitude, and the time varying topography of the ground below it. Adjusting an operating or data processing condition of each geophysical instrument using the respective background response and the instrument's attitude to enhance the performance of that instrument.

Abstract: A system for non-destructive non-contact quality inspection of dry electrode units of energy storage includes an eddy current-based inspection system having a conveyor belt, and a hollow dielectric shell. An outer surface of the shell has a plurality of spaced apart measuring transducers. Each of the transducers include a feed-through eddy current probe and at least two strap capacitors spatially linked therewith. In the related method, an electrode unit to be inspected is placed on the conveyor belt and enters and moves through the dielectric shell. The electrode unit is excited using a magnetic field from the eddy current probe as it passes by each of the plurality of transducers, where eddy currents at a plurality of frequencies are induced in the electrode unit. The modulation characteristics of impedance at a plurality of frequencies are measured by the probes, and from the impedance data it is determined whether the electrode unit is defective.

Abstract: The invention pertains to an eddy current sensor with a sensor circuit having a head portion, including a sensor coil, a base portion and a transmission cable connecting the head portion to the base portion. The transmission cable is a triaxial cable and the sensor coil is connected between the inner conductor and the outer shield of this cable. The base portion of the sensor circuit comprises a voltage follower connected to buffer the voltage of the center conductor and apply it to the inner shield of the triaxial cable in order to isolate the cable's line capacitance from the sensor coil. The invention further concerns a sensor coil for an eddy current sensor, having a segmented winding structure with a particularly low self-capacitance. In a preferred embodiment, the triaxial transmission cable is combined with a sensor coil having this segmented winding structure.

Abstract: A thickness detecting apparatus comprises a printed board in a part of which a coil is patterned, a detection roller which is disposed near the coil, which detects thickness of a sheet P of paper as a displacement amount, and a thickness detection circuit mounted on the surface of the printed board, which supplies a high frequency signal to the coil via a wiring pattern formed on the surface of the printed board and detects the amplitude of the high frequency signal which changes according to the displacement amount of the detection roller as a thickness of the sheet P of paper.

Abstract: A method for tracking an object includes producing energy fields at a plurality of different frequencies in a vicinity of the object, and receiving signals that are generated at a location of the object at the different frequencies in response to the energy fields. Multiple computations are made of spatial coordinates of the object based on the signals received at the different frequencies. Convergence of the computations is tested in order to ascertain whether the energy fields have been perturbed by an article in the vicinity of the object.

Abstract: A magnetic encoder apparatus has a housing that includes a base portion and a cover plate portion. The housing also has a magnet that is contained in the base portion of the housing, a sensor chip having a major surface located adjacent to the magnet, and an alignment spacer having a first side and a second side. The first side of the alignment spacer has an opening through to the second side of the alignment spacer, and the second side fits into the base portion of the housing. The opening of the alignment spacer encloses the sensor chip.