Abstract: A method for non-contact measurement of dimensions such as thickness or diameter and electrical characteristics of an electrically conductive object (6) based on electromagnetic induction and a time-varying magnetic field. A substantially constant current is supplied to at least one transmitter coil (3) such that an electromagnetic field penetrates the object (6). Current to the transmitter coil (3) is cut off and a voltage induced in at least one receiving coil (8) by at least one decaying magnetic field. The voltage in receiving coil (8) is measured from a first time following decay of a magnetic field in the air (T3) until a time when the field has decayed to zero (T4, T5, T6) and the signal is integrated. A value for a physical dimension of the object (6) is calculated from this integral. The method is accurate, undisturbed by surface contamination or object movement, and applicable to different geometric forms including plate, bar or tube.

Abstract: An apparatus for measuring pressure in a medium includes a laser for emitting linearly polarized light; a polarizing beam splitter that reflects the linearly polarized light from the laser; a first lens that receives and focuses the linearly polarized light from the polarizing beam splitter; an optical fiber having first and second ends, the first end for receiving the linearly polarized light from the first lens, the second end comprising a tip disposed in the medium, the tip receiving reflected light from the medium, the reflected light being transmitted back through the optical fiber and the first lens to the polarizing beam splitter; the polarizing beam splitter transmitting the reflected light that has polarization orthogonal to the linearly polarized light emitted by the laser but not transmitting the reflected light that has polarization substantially parallel to the linearly polarized light emitted by the laser; a second lens for receiving the reflected light that has polarization orthogonal to the li

Abstract: An antenna transponder configuration, in particular for power transmission and angle measurement is described. The antenna transponder configuration contains a stationary antenna device having at least two concentric coils with different mean radii, the mean magnetic flux in the interior of the coils approximately canceling itself out. At least one of the coils is in this case in the form of a meandering coil. A transponder, which is disposed such that it can rotate, has a configuration of coils that are inductively coupled to the magnetic field of the meandering coil. The transponder and the antenna device are separated from one another by an air gap.

Abstract: A testing apparatus (10) is provided to securely detect a mounting error of a fittable member (5) on a connector (1). The testing apparatus (10) has a testing unit (20) for detecting an ajar state of the fittable member (5) on a housing (2) of a connector (1). The testing unit (20) is provided with an elastic contact (22) for elastically contacting the housing (2) of the connector I1) along locking direction (Y) in which the fittable member (5) is locked with the housing (2). This elastic contact (22) is provided with a switch (23) for detecting the ajar state of the fittable member (5) at a contact position of the elastic contact (22) with the housing (2).

Abstract: A method for performing time domain reflectometry contemporaneously with recurrent transmissions, such as idle transmissions, on a computer network, such as a 100 BASE T protocol network is disclosed. This method comprises detecting the recurrent transmissions and then storing representations of those transmissions. A probe signal, such as a TDR signal, is then generated onto the computer network during the recurrent transmissions. A response of the network to the probe signal combined with the recurrent transmissions is then detected. The signal transmission characteristics of the network are then analyzable based on the response to the probe signal using the stored representations of the recurrent transmissions, using deconvolution, for example.

Abstract: A contactless angular offset analog sensor, of the magnetic inductance type, includes a first portion forming a detector. The detector includes at least one substrate plate carrying at least one flat spiral winding, and at least one core layer of material with high magnetic permeability and low saturation field over at least one portion of the winding. The detector is adapted to coact with a device for processing the electrical signal measured at the terminals of the winding. The sensor also includes two rotors each having at least one magnet, disposed over a predetermined angular sector. The rotors are movable about a same axis identical to the axis of the winding. Each magnet generates in the plane of the core layer a magnetic field of a value greater than the saturation field of the core layer over at least a portion of the surface of the winding.

Abstract: A photoreceiver assembly for accurately separating at least one low level, high frequency signal carried from a large, low frequency pulse. Illustratively, in one exemplary embodiment, the photoreceiver assembly extracts a high frequency ultrasonic signal from the optical frequency of light by shining that ultrasonic base band signal onto a photodetector for conversion into an electrical signal in the bandwidth of interest. The photoreceiver assembly includes a photodetector and a splitter coupled to the photodetector. The splitter is also coupled to a plurality of transimpedance signal paths. In operation, the splitter receives a current from the photodetector, separates, and directs the current to the plurality of transimpedance signal paths. In one exemplarily embodiment, the photoreceiver further includes a transimpedance amplifier assembly coupled to at least one path of the transimpedance signal paths.

Abstract: A grating based optical wavelength demultiplexer that can be used for multiple wavelength bands over a wide wavelength range is presented. The spectral response of the device is cyclic. The free spectral range of the grating is designed to be large enough to contain all the wavelength channels to be demultiplexed within a band but small compared to the overall wavelength window of the network application so that a multiplexed signal within any one of the wavelength bands within the application window can be demultiplexed by the same device. This device, being bidirectional will also operate as a multiplexer. By using such a cyclic design, an organization will not need to stock different parts for each band and thus significantly reduce the inventory cost.

Abstract: An angular position detecting apparatus using a magnetic detecting element, which can voluntary widely set an output change characteristic of the magnetic detecting element with respect to angular positions. An angular position detecting apparatus includes a cylindrical yoke, and a magnet fixed to a predetermined position in the cylindrical yoke. A magnetic detecting element, which is fixed to a rotor, is provided in a magnetic field generated between the magnet and the cylindrical yoke, so that a position of the magnetic detecting element is shifted from a rotation axis P of the rotor by a predetermined distance r. A ferromagnetic thin film magnetic resistance element applies a magnetic field which has intensity so that outputs from the elements are saturated. As a result, the magnetic detecting element generates outputs depending only on a magnetic flux detection angle &thgr;s independent of an influence of changes of magnetic field intensity due to temperature changes.

Abstract: In a photosensitive device wherein a photodiode is operated by placing an initial fat zero charge thereon before the integration of a light-induced signal, the actual dark level signal created by the fat zero charge is sampled with each readout from the photodiode, and then retransferred to the photodiode. After integration, the sampled dark level is subtracted from the total signal level on the photodiode. In this way both fixed-pattern and thermally-induced noise is obviated.

Abstract: A device for implementing a method for predicting rotational positions of a rotating shaft is disclosed. A motor shaft is rotated over a range of rotation. The device detects each incremental rotation position of the motor shaft from a set of incremental rotational positions being spaced by a fixed increment. Prior to a change in the rotational speed of the motor shaft, the device generates a prediction of each rotational position. When a detected incremental rotation indicates a change in rotational speed of the motor shaft, the device modifies the prediction of each motor shaft position in a continuous manner.

Abstract: A method for detecting failures in microactuator motors in head suspensions including exciting the head suspension at its natural resonant frequency, monitoring and evaluating the voltage produced by one or both piezoelectric elements in the motor, and comparing the voltage produced with one or more voltage waveforms corresponding to a properly functioning and mounted motor in response to a similar input. The method also includes applying a sweep frequency signal to provide visibility of a microcrack in the motor that may initially be concealed by plating on the motor.

Abstract: A temperature sensing apparatus including a sensor element made of a magnetically soft material operatively arranged within a first and second time-varying interrogation magnetic field, the first time-varying magnetic field being generated at a frequency higher than that for the second magnetic field. A receiver, remote from the sensor element, is engaged to measure intensity of electromagnetic emissions from the sensor element to identify a relative maximum amplitude value for each of a plurality of higher-order harmonic frequency amplitudes so measured. A unit then determines a value for temperature (or other parameter of interst) using the relative maximum harmonic amplitude values identified. In other aspects of the invention, the focus is on an apparatus and technique for determining a value for of stress condition of a solid analyte and for determining a value for corrosion, using the relative maximum harmonic amplitude values identified.

Abstract: A sensor system for determining the position of an edge of a moving web of material travelling along a predetermined travel path. the sensor system comprising a transmitter/receiver assembly, a beam reflector assembly and sensor signal processing. The transmitter/receiver assembly is positioned adjacent to the travel path of the moving web of material. The transmitter/receiver assembly has a transmitter transmitting a light curtain across at least a portion of the travel path, and a receiver receiving a shifted light curtain transmitted across at least a portion of the travel path and generating video output signals indicative of the position of the edge of the moving web of material. The beam reflector assembly is also positioned adjacent to the travel path of the moving web of material such that the travel path passes between the transmitter/receiver assembly and the beam reflector assembly.

Abstract: Disclosed is a method for improving the sensitivity of a fluxgate magnetometer for which high-order harmonics are detected and utilized in determining a weak external magnetic field expressed in the core region. These harmonic signals are processed coherently so as to increase the signal-to-noise ratio, since noise can only add to the signal incoherently at these harmonic frequencies. Also disclosed is a method for improving the sensitivity of a fluxgate magnetometer for which the technique of waveform autocorrelation is used in determining a weak external magnetic field expressed in the core region. By convolving the gated signal with a waveform duplicating the signal itself, noise content is effectively suppressed, thereby increasing the resolution power of the fluxgate magnetometer.

Abstract: A method and system for detecting or measuring defects in a rope having ferromagnetic tension members includes a magnetic field exciter and an array of magnetic flux sensors corresponding to the tension members in a known relationship. Measurements of magnetic flux leakage are indicative of defects. Another aspect of the invention includes a method and system for detecting or measuring defects in an elevator rope having electrically conductive tension members, whereby measured electrical resistance in the tension members is indicative of defects.

Abstract: A magnetic detection device capable of detecting moving direction of a toothed magnetic movement body is provided. The magnetic detection device comprises a circuit for converting output signals of plural magneto-resistance effect elements 21 and 22 located in moving direction of toothed magnetic movable body to a ternary signal of a high level, a low level 1 and a low level 2, and in which a binary signal of the high level and the low level 1 is output when the toothed magnetic movement body is rotated in forward direction and a binary signal of the high level and the low level 2 is output when the toothed magnetic movement body is rotated in reverse direction.

Abstract: A molded plastic coaxial connector. The coaxial connector is fabricated within a stacking connector system of a mini PCI card. A plastic protuberance having a cavity and a corresponding depression having a center conductor pin are molded to the dimensions corresponding to a desired characteristic impedance. The plastic is then coated with a conductive material. When the protuberance is mated to the depression, the coated surfaces of each form the ground shield of a coaxial connection and the center conducting pin is mated to the cavity to form the drive point of the coaxial connection. Fabricating the coaxial connection from plastic reduces the number of processes and eliminates the need for individually machined parts, thereby reducing the production costs. In one embodiment multiple coaxial connectors may be implemented along a single piece of plastic. This allows for reduction in size as the tolerance buildup of conventional coaxial connectors is avoided.

Abstract: Raman amplifiers are provided for amplifying signals on optical communications links. The Raman amplifiers may be pumped using an unpolarized Raman pump source. Gain for the source may be provided by a semiconductor device that provides linearly-polarized pump light. A polarization-maintaining fiber may be coupled directly to the semiconductor device at a 45° orientation with respect to the polarization of the light emitted by the device. Light from the semiconductor device may be launched equally into both the slow and fast axes of the fiber. A fiber Bragg grating reflector may be used to stabilize the pump. Pump light traveling along the slow and fast axes becomes spatially separated by more than the coherence length of the multiple quantum well device. The pump light exiting the end of the polarization-maintaining fiber is therefore unpolarized.

Abstract: A method and apparatus is shown for implementing magnetostrictive sensor techniques for the nondestructive evaluation of ferromagnetic pipes or tubes. A magnetostrictive sensor generates shear waves and/or torsional waves in ferromagnetic pipes or tubes, which waves travel therethrough in a direction parallel to the longitudinal axis of the pipe. A circumferential magnetization is generated in the ferromagnetic pipe or tube by a DC or low frequency voltage establishing a current along the longitudinal axis and past the magnetostrictive sensor. Reflected shear or torsional waves may represent defects in the pipe or tube.