Abstract: Improved receiver antennas are disclosed for long offset tensor induction army logging tools. The disclosed antennas include a bobbin which accommodates a ferromagnetic core. The outer surface of the bobbin is wrapped around a binding so that winding is thicker or includes more turns towards a center of the bobbin and is thinner or includes less turns towards the outer ends of the bobbin. The result is that the primary winding with a curved or parabolic profile that enhances the effective magnetic permeability and magnetic moment of the antenna. A secondary winding may also be utilized for flux feedback compensation. The elimination of winding turns towards the ends of the magnetic coil result in reduced DC resistance and the reduction in parasitic capacitance of the antennas. The disclosed antennas may be used in x-y-z receiver arrays.

Abstract: An electrical device includes a terminal connected with an electronic component, a pliant member which contacts a part of the terminal in a longitudinal direction of the terminal and covers a whole circumference of the part, and a casing for holding the electronic component and the terminal and the pliant member. The casing is molded by a resin material with the electronic component, the terminal and the pliant member being insert-molded. The end portion of the terminal of an opposite side to the electronic component extends to an outer side of the casing. One part of the pliant member is covered by the casing and the other part thereof is exposed to the outer side of the casing. The pliant member is compressed in a direction substantially orthogonal to the longitudinal direction of the terminal.

Abstract: A method for determining electrical properties of a submarine petroleum fluid-bearing formation (1) under overburden geological layers (2) of thickness (s) under a seafloor (3) of a sea. The method includes: *arranging one or more transmitter antennas (9) in the sea, and arranging one or more electromagnetic receivers (8) in the sea, *the sea having a shallow sea depth (d) of 50-350 meters; *using the transmitter antenna (9) transmitting electromagnetic signals (10) of one or more pulses (11) having frequency of very low frequency between 0.01 Hz and 0.

Abstract: Apparatus and method for harvesting energy from the environment and/or other external sources and converting it to useful electrical energy. The harvester does not contain a permanent magnet or other local field source but instead relies on the earth's magnetic field of another source of a magnetic field that is external to the sensing device. One advantage of these new harvesters is that they can be made smaller and lighter than energy harvesters that contain a magnet and/or an inertial mass.

Abstract: A pressure distribution detector is less influence by installation environment, that is, a pressure distribution detector that detection sensitivity or detection accuracy is less adversely affected even if the device is fitted not only to a flat surface but also a surface having an arbitrary shape such as a curved surface. The pressure distribution detector comprises a plurality of drive coils (1) provided on a substrate, a plurality of detection coils (2) electromagnetically coupled with the plurality of drive coils in pairs respectively, and a spacer (4) for keeping a constant distance between the plurality of drive coils and the plurality of detection coils, respectively. In order to vary the degree of electromagnetic coupling between the drive coil and the detection coil, a variable electromagnetic coupling (3) formed of a conductor or a magnetic body is provided movably adjacent to the drive coil and/or the detection coil.

Abstract: Using eddy currents for automatic inspection of a rectilinear hole formed in a metal part. An eddy-current probe is carried by a drive system associated with a positioning baseplate that carries a calibration part including a hole similar to the hole for inspection and in alignment with an orifice thereof.

Abstract: A marine electromagnetic sensor cable includes a plurality of sensor modules disposed at spaced apart locations along a cable. Each module includes at least one pair of electrodes associated therewith. The electrodes are arranged to measure electric field in a direction along the direction of the cable. A plurality of spaced apart magnetic field sensors is associated with each module and arranged to enable determining an electric field amplitude in a direction transverse to the direction of the cable from magnetic field gradient.

Abstract: After the periphery of the magnetic sensitive element is surrounded by an elastic member, the magnetic sensitive element is mold-formed with resin material. Soft epoxy or gel resin is employed as the elastic member, poured in an element-mounting space and solidified. The magnetic sensitive element is surrounded by silicone rubber. Such construction allows the magnetic sensitive element not to be affected by vibration and allows the elastic member to absorb the stress which is created due to the thermal deformation of the molded resin.

Abstract: A magnetic encoder constituting rotation detector in combination with a magnetic sensor, comprising a circular multipolar magnet and a metal reinforcing ring to which the circular multipolar magnet is fixed is disclosed. The encoder is characterized by a projecting portion which is provided at a surface of the circular multipolar magnet facing to the metal reinforcing ring, so as to form an adhesive space to secure uniform adhesive layer between metal reinforcing ring and the circular multipolar magnet, thereby preventing from being peeled off or cracked. And the height of the projecting portion is adapted to define the thickness of the adhesive layer.

Abstract: A first sensor detects a rotational position of a first shaft in a noncontact fashion and generates a first output signal by phase-shifting a reference A.C. signal in accordance with the detected rotational position of the first shaft. A second sensor detects a rotational position of a second shaft in a noncontact fashion and generates a second output signal by phase-shifting the reference A.C. signal in accordance with the detected rotational position of the second shaft. First and second timing signals corresponding to phase shift amounts of the first and second output signals are output via respective output lines. Relative rotational position detection data, representing a rotational difference or amount of torsion between the two shafts, appears in a time difference between the first and second timing signals. A PWM signal, having a pulse width corresponding to a time difference between the first and second timing signals, may be output.

Abstract: A magnetoresistive (MR) sensing device includes MR elements electrically connected to form a bridge circuit and one or more non-functional (or “dummy”) MR elements for improved matching of the bridge circuit MR elements.

Abstract: A rotary encoder includes two component groups arranged in a manner allowing rotation relative to each other about an axis, the first component group having a triggering sensor and a plurality of magnetic sensors. The second component group includes a first magnet, a second magnet, and a third magnet. The component groups are configured such that, in response to a full revolution, the magnetic field of the first magnet and of the third magnet are detectable by the magnetic sensors. A trigger signal is able to be generated by the triggering sensor due to the second magnet and the third magnet, while the first magnet does not bring about a triggering of a trigger signal by the trigger sensor.

Abstract: A vibration canceling circuit for a metal detector. The metal detector includes a transmit coil, first and second receive coils, a differential circuit coupled to the first and second receive coils, a controller coupled to the differential circuit, and a vibration canceling circuit coupled to the controller. The controller uses a signal provided by the vibration canceling circuit to remove a vibration component from a metal detection signal.

Abstract: The invention concerns a system for determining the position of mobile element relative to a stationary structure, the system comprising an encoder configured to emit a pseudo-sinusoidal spatial signal representing the position of the encoder, a sensor (2) comprising a current-loop mount between at least two resistive elements (3) and a signal processing device Vi configured to supply two quadrature signals respectively SIN and COS of same amplitude. The invention also concerns an antifriction bearing equipped with such a system for determining the angular position of the rotating ring relative to the stationary ring.

Abstract: A magnetic sensor that is inexpensive and suppresses changes in offset voltage caused by wear. The magnetic sensor includes magnetoresistance elements having electrical resistances that change in accordance with magnetism changes. The magnetic sensor detects magnetism based on changes in the electrical resistances. The magnetoresistance elements are covered by a protective film. Part of the protective film is etched and eliminated to form a recess.

Abstract: The invention provides an eddy current testing method for an internal finned pipe or tube which can securely detect a micro defect generated in a trough portion in an inner surface of the pipe or tube, even in the case that an inner surface shape of the internal finned pipe or tube is ununiform in a circumferential direction of the pipe or tube. The eddy current testing method in accordance with the invention detects a defect existing in a trough portion of the pipe or tube (P) by arranging a differential coil (2) constructed by a pair of coils (21, 22) having such a dimension as to be arranged within the trough portion of the pipe or tube (P) and coming away from each other in an axial direction (X) of the coil, within the trough portion of the pipe or tube (P) along a direction in which the trough portion of the pipe or tube (P) extends, and relatively moving the differential coil (2) in the direction in which the trough portion of the pipe or tube (P) extends.

Abstract: Provided is an electromagnetic coil arrangement comprising a set of electromagnetic sensors at fixed locations with respect to each other, each of the electromagnetic sensors comprising a planar coil coupled to a conductive layer, the planar coil comprising non-concentric rings. Further, provided is an electromagnetic tracking system, comprising an electromagnetic coil arrangement, at least one complementary electromagnetic sensor and a processor configured to process a signal comprising data indicative of a mutual inductance between the at least one complementary electromagnetic sensor and each of the set of the electromagnetic sensors of the electromagnetic coil arrangement. Also, provided are a method of tracking and a method of manufacturing an electromagnetic coil arrangement.

Abstract: A semiconductor device including a Hall effect sensor and related method. The Hall effect device includes a substrate having a first conductivity type and an epitaxial layer having a second conductivity type defining a Hall effect portion. A conductive buried layer having the second conductivity type is situated between the epitaxial layer and the substrate. First and second output terminals and first and second voltage terminals are provided, with the second voltage terminal being coupled to the conductive buried layer.

Abstract: A method for coding an output signal of a sensor of an apparatus for determining a rotation angle of a shaft, in particular of a crankshaft of an internal combustion engine, the shaft being joined to a sensor wheel having teeth and tooth gaps having an asymmetrical pitch, and the sensor wheel having associated with it at least one differential sensor encompassing two sensor elements, the differential sensor generating an output signal that is a difference of signals of the two sensor elements, the output signal being a square-wave signal that can assume a first value or a second value. The rotation direction of the shaft, as well as a pitch ratio of a tooth sweeping past the sensor with respect to an adjacent tooth gap, are ascertained from the signals of the two sensor elements, and the rotation direction as well as the pitch are coded as a pulse width coded output signal.

Abstract: A device rotates at least one static magnetic field about an axis, producing a rotating magnetic dipole field, and is movable in relation to the surface of the ground. The field is periodically sensed using a receiver to produce a receiver output responsive to the field. A positional relationship between the receiver and the device is monitored using the output. In one aspect, changing the positional relationship, by moving the device nearer to a boring tool which supports the receiver, causes an increase in accuracy of depth determination. In another aspect, determination of an actual overhead position of the boring tool, and its application, are described. Use of a plurality of measurements over at least one-half revolution of each magnet is disclosed. Establishing a surface radial direction toward a boring tool and resolution of multi-valued parameters is described. Calibration techniques, as well as a three transmitter configuration are also described.