Abstract: A sensor is provided for changing an operational characteristic of a circuit within a housing structure of the sensor to a preselected stimulus. The circuit within the housing structure is provided with magnetically sensitive components to change an operational parameter thereof. An object is provided to change the status of the magnetically sensitive component. The present invention incorporates a Hall effect element within the housing structure that is placed proximate a permanent magnet. Between the magnet and the Hall effect element a depression is formed to permit the insertion of a magnetically permeable object to change the magnetic field. The change in the magnetic field creates a change in the status of the Hall effect element and permits the circuit to change its operational characteristic.

Abstract: An apparatus for detecting an angular position of a crankshaft of an internal combustion engine includes a disk which is rotatable in synchronism with the rotation of the crankshaft, a row of magnetic elements disposed on the disk along a circumferential periphery thereof at circumferentially equal intervals, an electromagnetic pick-up device disposed orthogonally to a plane of rotation of the disk in opposition to the row of magnetic elements, and a shaping circuit for shaping an output signal of the electromagnetic pick-up device into a rectangular waveform signal. The shaping circuit is combined integrally with the electromagnetic pick-up device into a single unit to prevent external noise from being superposed on the output signal from the pick-up device. The shaping circuit includes an integrator for integrating the output signal to produce a reference signal for the comparator.

Abstract: The apparatus of the invention is a segmented pig body having an electrical instrumentation subassembly mounted thereto. The subassembly consists of a plurality sensors for electromagnetically coupling to the inner surface of the pipeline, each of which generates a signal that varies as the localized relative permeability of the pipeline metal; an odometer assembly for generating correlating data; and an instrument for recording the signal and data for later analysis. The method of the invention comprises passing the pig through the pipeline while it is electromagnetically coupled by the sensors to the inner surface of the pipeline. During the pass, signals varying with the localized magnetic permeability of the pipeline wall and correlative data are generated and recorded. After the pass, the correlative data is used to correlate the signals to wall locations to locate stress occurrences.

Abstract: An eddy current probe for detecting material flaws by inducing and measuring eddy currents in the surface of a material. The probe is held at a constant lift-off distance from the surface by a probe carriage that slides across the surface in a straight scan line. The carriage moves relative to a motorized bracket that slides the carriage across the surface. This relative movement allows the carriage to move across an uneven surface without deflecting the probe from a straight scan line. The probe has a split core so that an adjacent pair of coils project and detect electromagnetic fields on the surface being measured. Both coils have opposing flat sides that allow the coils to be closely packed together within the probe body.

Abstract: A circuit is disclosed for detecting a conductive region in a body. The circuit includes a remote module (12) coupled to a driver and logic module (14). The remote module is mountable on a probe (16) and senses contact between a conductive detector electrode and the conductive region. The driver and logic module provides energy to the remote module and responds to the operation of the remote module by producing an output indicative of detection of the conductive region. In the preferred arrangement, current from a constant current source Q.sub.4 normally flows through a first transistor Q.sub.1, which is maintained in an "on" state by a charged capacitor C.sub.1. When the detector electrode contacts the conductive region, however, charge is bled from the capacitor, switching the first transistor to an "off" state and causing the current from the current source to be redirected to a switching transistor Q.sub.3.

Abstract: Disclosed is an apparatus for detecting magnetically conductive metals in a flow of material. The apparatus includes a metal casing open at both ends thereof and adopted to receive the material flow therethrough. Magnet bars are attached at two opposite inner walls of the casing in such a manner that, on one side, the north poles are directed inwards into the casing and the south poles are attached magnetically conductively to the casing, and on the other side the polarity of the magnetic bars is opposite, detector means being provided at the two remaining walls of the casing so as to detect the magnetic field at those positions. Finally, electronic circuit elements are connected to the detectors in order to convert the detected magnetic field variations into an observable form. The material flow may take place in a trough positioned within and extending through the casing.

Abstract: A device for uncovering imperfections in electrical conducting wire, particularly superconducting wire, by detecting variations in eddy currents. Eddy currents effect the magnetic field in a gap of an inductor, contained in a modified commercial ferrite core, through which the wire being tested is passed. A small increase or decrease in the amount of conductive material, such as copper, in a fixed cross section of wire will unbalance a bridge used to measure the impedance of the inductor, tripping a detector and sounding an alarm.

Abstract: An apparatus for magnetically detecting a position of a movable magnetic body includes a three-terminal magnetic field-intensity sensing structure formed by a pair of magneto-resistors. The magnetic field-intensity sensing structure is disposed opposite to a magnetic body arranged for movement relative thereto in a magnetic field and generates a first electrical signal of sinusoidal waveform in response to a change in the intensity of the magnetic field due to the relative movement of the magnetic body. This first electrical signal appears from the apparatus as a second electrical signal of rectangular waveform or of sinusoidal waveform having an amplified amplitude. Components of the circuit for shaping the waveform of or amplifying the amplitude of the first electrical signal are integrally mounted together with the magneto-resistors on a substrate. Preferably, the shaping or amplifying circuit is in the form of a hybrid integrated circuit formed on the substrate.

Abstract: A measuring instrument capable of providing its readouts of measurements of a physical quantity such as voltage, current or resistance includes voice synthesizer circuitry which may be realized by the use of a large scale integrated circuit (LSI) chip. A mode selector switch is provided for selection of an audible indication mode and a visual indication mode.

Abstract: A combination of magnetics and a special geometric environment is employed to distinguish whether an instrument is positioned within a pipe formed of magnetizable or non-magnetizable material, and is the basis, in part, for a method and an apparatus used in controlling picture taking at the bottom of a well bore. A coil is energized repetitively in a circuit in which the voltage across the coil, or the current that flows through the coil, can be measured. Whether the coil is in a magnetic or non-magnetic environment is determined by the magnitude of the change in coil voltage or current.

Abstract: A thermoregulated magnetic susceptibility sensor assembly for well-logging or the like is disclosed. The assembly includes a sensing solenoid and a non-metallic container for the sensing solenoid. Located in the container and spaced from the sensing solenoid are a plurality of heaters. These heaters are uniformly positioned about the sensing solenoid and a heat transfer material is located between the heaters and the sensing solenoid. The heat transfer material conducts the heat from the heaters to the sensing solenoid in a substantially uniform manner so that the sensing solenoid is maintained at a uniform temperature. Preferably, temperature sensors are provided to control the heat output of the heaters to maintain the sensing solenoid at the desired uniform temperature. To minimize heat transfer to the heaters from the external environment, a layer of insulation is provided around the heaters.

Abstract: A fixture is provided for holding a cable end connector to which wires are to be attached. The fixture includes an indicating element for each of the connection elements of the connector to be wired. A separate fiber-optic cable extends from each indicating element to a separate light source for individually providing illumination to the separate indicating elements. A means is provided for making an electrical connection to individual electrical elements to separately identify each of the different wires to be assembled, and an electrical driving means is connected to respond to the electrical connection means for energizing the corresponding one of the light sources corresponding to the connection element to which the associated wire is to be assembled.

Abstract: Apparatus for detecting the presence of a metal strand in paper, for example in a document or bank note of which one wishes to check the authenticity, comprises means for moving the paper in front of a detection head comprising a coil a resonance circuit supplied by a high frequency source, the frequency of which is close to the resonance frequency of the circuit. The high frequency voltage is modulated by variation of the current in the resonance circuit when the strand passes the detection head. After filtering and amplification, the demodulated signal is applied to a trigger circuit to obtain a digital signal. Delivery of the digital signal to an output terminal is checked by means of a reading window, the opening of which is controlled by the means for moving the paper. The output of the detection head is also applied to a second trigger for checking maintenance of a continuous component in the signal from the resonance to verify continuity of the coil circuit.

Abstract: An instrument for locating the position of hidden live continuous or broken wires utilizes an indicator such as a series of light emitting diodes to indicate the adjacency or the strength of the electrostatic field surrounding the wire. By watching the number of light emitting diodes lit, the instrument can be brought directly to the wire. The instrument is comprised of an antenna connected to the high input impedance of an amplifier, a low pass filter connected to the output of the amplifier, a lamp operation circuit and an indication means connected to the lamp operation circuit.