Showing papers on "Inductive sensor published in 1989"

Temperature stable proximity sensor with sensing of flux emanating from the lateral surface of a magnet

Abstract: A ferrous object sensor assembly is capable of sensing the presence or absence of an object of high magnetic permeability, such as a tooth or notch on a rotatably mounted ferrous wheel at zero speed and immediately upon power-up and, thus, may also be used as a proximity sensor. The ferrous object sensor assembly is comprised of a permanent magnet and a magnetic flux responsive sensor having a sensing plane which produces an electrical output signal which varies as a function of the change in magnetic flux density. The ferrous body sensor assembly does not rely upon pole face magnetism as some known conventional sensors but, rather, relies upon a the radial component of magnetic flux density emanating from a lateral surface of the magnet, intermediate opposing pole faces. Since the ferrous object sensor assembly does not rely on pole face magnetism, its electrical output signal is relatively stable over a relatively wide temperature range.

Power line post insulator with dual inductor current sensor

Abstract: A power line post insulator has a housing that encloses two inductive sensors that transversely straddle a recess which receives the power conductor Wires connect the sensors additively with respect to voltages induced by currents in the conductor between the sensors The sensors may each include one or two additively connected coils

Magneto-inductive sensor for performing tactile and proximity sensing

Abstract: The present invention discloses a single sensor performing both tactile and proximity sensing. The sensor includes a magnetic field generator, a magnetic field sensor for sensing changes in the magnetic field in response to an object changing position with respect to the field to provide proximity sensing. By providing for relative movement between the response to the object touching the sensor, tactile sensing is provided.

Door cocking device with contactless state indication - uses coded strips of magnetic material in conjunction with inductive detector

Abstract: The locking device including locking bolt (2) with two coded stripes (4,6), mounting plate (8), control circuitry (12,14), E core (10) with coils (16,18) on outer limbs (20). The locking bolt (2) has two coded segments (4,6) made from magnetic material in order that an inductive sensor with associated circuitry can determine the position of the coded segments (4,6) without direct contact. Pref., the coding of bolt is digital. USE/ADVANTAGE - Locking devices for doors esp. in vehicles. Avoids use of microswitches to detect bolt position.

Proximity switch for detecting a magnetic inductive field

Abstract: An inductive proximity switch comprises a high-frequency oscillator, an oscillator coil and an oscillator core. An analyzing circuit detects the inclination amplitude depending on the degree of core saturation. The analyzing circuit triggers a switching process when a certain threshold value of amplitude is reached. The core consists, for example, of ferrite. A yoke-like body is assigned to the core. The use of such a soft-magnetic material for the yoke-like body, allows the construction of smaller sensors with a higher sensitivity and a more cost-advantageous production. Their permeability curve in relation with one quadrant of the coordinate system is clearaly S-shaped.

Optical transducer systems

Abstract: An optical transducer system for producing an optical output signal representative of the rotational speed of a rotary member, particularly a shaft of a gas turbine engine, comprises a conventional inductive speed probe positioned adjacent the shaft to sense the passing of the teeth of a toothed wheel secured to and rotatable with the shaft. The inductive sensor thus produces an AC output signal whose frequency is proportional to the rotational speed of the shaft, and this signal is used to excite electrostatically vibration of a cantilever beam micromachined in silicon. The vibrating beam is arranged in an optical path defined by one or more optical fibres, such that its vibrations modulate light directed along the optical path at a frequency which is again proportional to the rotational speed of the shaft.

Inductive sensor arrangement and measuring arrangement determining the relative position of a sensor arrangement

Abstract: An inductive sensor arrangement exhibits a transmitter coil (1) which is fed by a high-frequency oscillator (3) The transmitter coil (1) generates a spatial electromagnetic field (5) Two coil arrangements (6 and 9) in which a current is induced by the transmitter coil (1), are inductively coupled to the transmitter coil (1) Two first receiver part windings (6a, 6b) are arranged in such a manner that they are exposed to different induction with an unsymmetric position with respect to object irregularities, for example gaps in a metal body This makes it possible to detect lateral offset signals of the part windings (6a and 6b) with respect to the irregularity (4c) of the object (4) Such signals, which indicate the lateral offset of the object irregularity, can be obtained by directly or indirectly connecting the outputs of the two part windings (6a, 6b) in opposition to one another In addition, a second coil arrangement (9) is provided which exhibits an equal number of receiver part windings (9a, 9b) to the first coil arrangement (6) The part windings (9a, 9b) are arranged approximately in line with the part windings (6a, 6b) above the object By comparing the output signals of the associated part windings of the two coil arrangements (6a, 9a and 6b, 9b), signals can be obtained which have a relationship to the distance between the sensor arrangement and the metallic object (4) If the distance signals of the two pairs of part windings (6a, 9a and 6b, 9b) differ from one another, correction signals can be obtained from this

Distance measuring device and method for use with vehicles

Abstract: A means is provided for measuring distance travelled by a vehicle having a wheel coupled to a vehicle axle disposed within a vehicle axle housing, with the wheel haivng at least one nonmagnetized metal region which rotates with the wheel defining an orbit through which the nonmagnetized metal region passes as the wheel rotates to advance the vehicle. The apparatus includes an inductive proximity sensor and a counter means. The inductive proximity sensor is of the type adapted for detecting the presence of nonmagnetized metal within a sensing distance and producing an electrical response thereto; it is coupled to the vehicle axle housing a preselected distance from the orbit of the nonmagnetized metal region, so that the nonmagnetized metal region is within sensing distance as it passes by the inductive proximity sensor. The counter is coupled to the inductive proximity sensor for receiving the electrical response and producing a display corresponding to the distance travelled by the vehicle.

Fault indicator with timing control

Abstract: In the disclosed fault indicator a sensing device is arranged for location in the magnetic field surrounding a conductor, an electronic device responsive to the sensing device assumes a first state in response to the sensing device sensing a trip condition and remains in the first state until set to a second state, a signaling device coupled to the electronic device serves for generating a signal only in response to the electronic device being in the first state, and a timing device responsive to the electronic device assumes the first state serves for setting the electronic device to the second state after a predetermined period. The sensing device is an inductive sensor, preferably a coil with an axis transverse to the conductor. In one embodiment an inrush restraint circuit renders the electronic device insensitive to inrush currents.

Inductive sensor for radial magnetic bearing

Abstract: The inductive sensor comprises a plurality of pairs of elementary position detectors. Each detector consists of a "U"-shaped piece 2 made of ferrite or ferromagnetic material, around which is wound an induction coil 3, and interacts with a reference ring 10 made of a conducting material situated in the same sectional plane and integral with the rotor 1. The reference ring 10 is mounted in an insulation bush 11 made of a non-magnetic material with a high electrical resistivity attached to the rotor 1 in order to isolate the reference ring 10 magnetically with respect to the rotor 1.

Method and system for exploiting the signals of linear inductive sensors, which system is adaptable for different sensor structures

Abstract: A method and system for exploiting the signals of linear inductive sensors, which system is adaptable for different sensor structures. The system is formed of a linear inductive displacement sensor provided with a primary coil and two identical symmetrical secondary coils which are in series and in antiphase. A mobile core and an alternative voltage source are mounted between the terminals of the primary coil wherein the amplitude of the voltage at the primary coil terminals is greater than the maximum amplitude of the voltage that can be taken at the secondary coil terminals. The method has the steps of forming the sum of the two alternative voltages present at the primary and secondary coils. These voltages are rectified by means of full wave rectifying and deriving the difference between the sum of recitified voltages. A continuous means valve corresponding to the difference is also derived.

Inductive proximity sensor with force transferring support post for use in high pressure environments

Abstract: A high pressure proximity sensor for high pressure environments uses a balanced bridge variable inductance magnetic core structure to detect the presence of a external ferrous object by a change in inductance. The sensor magnetic flux path is defined by the sensor's specific geometry which includes core windings on the core and a sensor housing. The core includes a center post of a nonmagnetic material to transfer stress from a housing sensor face to the core's symmetric axis to cancel the effect of an external pressure induced stress on the sensor. The center post is encircled by an elastomer barrier between the housing sensor face and an adjacent end of the internal core to prevent migration of an internal potting compound between the core end and the sensor face. This structure provides satisfactory sensor operation in environments imposing shock and vibration on the sensor as well as high external pressures.

Method of analysis of vibrations by a measuring system with automatic testing of the complete measuring chain for gas turbines

Abstract: The method for supervising the electronic units of a gas turbine, more particularly a gas turbine on an aircraft consists in determining the amplitude and the phase of the unbalance of each module of the gas turbine. To this end, there are provided accelerometers A1-A4 detecting the amplitude of the unbalance and inductive speed sensors 7A, B and 8A, B which are used to measure shaft speed and torque, and hence power. Each inductive sensor has an extended tooth on its toothed disc D to provide an identifiable pulse for each shaft revolution, and thus an indication of shaft angle. The phase of the unbalance output from the accelerometers is determined with respect to this angle. This phase remains constant for a module working properly but becomes unstable if the unit or any sensor becomes defective.

Inductive sensor with harmonic rejection for detecting the radial displacements of a rotor

Abstract: The radial inductive sensor with harmonic rejection comprises two pairs of detectors 221, 222 and 223, 224, each extending over approximately 60 DEG of the periphery of the reference ring 211, and each U-shaped detector piece 202 comprises first and second branches 204, 205, which are symmetrical with respect to the radial reference axis XX' or YY', along which the corresponding detector detects the radial displacements of the rotor with respect to the stator. This sensor rejects even harmonics and the third harmonic.

Control signal generator with joystick control lever

Abstract: The control signal genertor providing a pair of control signals has a joystick control lever (22) which can pivot in all directions relative to a pivot bearing (18), with an operating element (26) coupled directly to the control lever (22). An inductive sensor (34) cooperates with the operating elemetn (26), to indicate the displacement of the control lever (22) in a given direction, a second inductive sensor (38) providing its deflection in a second direction. Each sensor (34,38) has a spring biased rod (44) acted on by the operating element (26) and made of a magnetisable material. The rod is displaced axially relative to an indcution coil to alter the effective inductance and with an attached cam operating electrical switches.

Sensor system for monitoring acceleration

Abstract: A accelaration sensor system takes hybrid sensor arrangement which includes a low frequency range monitoring sensor and a high frequency range monitoring sensor. Both of the low frequency range monitoring sensor and a high frequency range monitoring sensor are connected to an electric circuit for supplying sensor signals thereof, which electric circuit selectively outputs one of the sensor signals as a sensor output. The electric circuit is set a boundary frequency for switching the low frequency monitoring sensor and the high frequency range monitoring sensor, which boundary frequency is set at a frequency within a frequency range where neither of sensor signals of the low frequency monitoring sensor and the high frequency range monitoring sensor is attenuated.

Induction gas measuring sensory device

Abstract: The utility model discloses an induction gas measuring sensory device belonging to an electronic measuring instrument A measuring meter with the mode of calibration of number of revolutions is provided with a sheet metal and a resonant inductive sensor The situation of the number of revolutions of the measuring meter is changed into an electrical signal and is exported The signal of each meter is changed into a standard signal and is respectively exported to a chip microprocessor at a position through the transmission for a long distance The data is centralized, is processed, is displayed or is printed The device has no influence for the working mode and the accuracy in measurement of the original measuring meter The induction gas measuring sensory device of the utility model belongs to the contactless induction transducing mode The service life is long The anti-interference capability for transferring signals for a long distance is strong The induction gas measuring sensory device can be applied to other meters with the metering mode of calibration of number of revolutions, such as a water meter, an electricity meter, etc

Method and device for adjusting an arrangement for contactless measurement of the relative position

Abstract: The invention relates to the adjustment of an arrangement for contactless measurement of the relative position between a capacitive and/or an inductive sensor (3, 3a) and a metallic workpiece (5). The inductance value or the capacitive value of the sensor (3, 3a) is influenced by the relative position of the workpiece (5). For the purpose of adjustment, an adjusting element (15) is inserted between the sensor (3, 3a) and the workpiece (5) or a metallic abutment (16) simulating the workpiece. The adjusting element (15) consists of an electrically insulating and/or of a paramagnetic or diamagnetic material. The adjusting element (15) determines both the relative position between the workpiece (5) or the abutment (16) simulating the workpiece and the sensor (3, 3a), and also prescribes the dielectric and magnetic behaviour in the zone of influence of the sensor (3, 3a).

Design of a controller for magnetic levitation

Abstract: In this work we will apply a linear quadratic regulator for the controller of the magnetic levitation of a rigid body. A successfull implementation with a diferentiator to estimate the velocity is showed, using a linear and not noisy displacement sensor. Another implementation with a pragmatic control policy that worked well with a noisy and strongly nonlinear sensor is presented.

Robotic sensor for object recognition

Abstract: The authors discuss the development of an electromagnetic sensor cell to do proximity sensing as well as tactile sensing. In this sensor cell, a magnetic coil (primary coil) is excited by a high-frequency voltage source producing a high-frequency magnetic field in the region. This field is coupled with another magnetic coil (sensor coil). The high-permeability sensor core (Metglass) causes the cell to be highly sensitive and any nearby interruption in the magnetic field gets amplified (proximity sensing). On the other hand, the two-mutually-coupled-coil configuration of the cell enables it to sense the pressure on its surface due to reduction in the distance between the two coils (pressure sensing). The tiny size of the sensor is one of the features that make it well suited for high-resolution sensing (dense packing). >

Numerical Simulation of Flaw Detection with a Capacitive Array Sensor Using Finite and Infinite Elements

Abstract: Capacitive array sensors are one among many electromagnetic techniques that can be used to detect flaws or other irregularities at or near the surface of materials. Capacitive sensors have an advantage over inductive sensors in that insulating materials may be interrogated as well as conducting materials. These sensors have seen some application in nondestructive evaluation, including flaw detection, the monitoring of porosity and thickness of thermal barrier coatings, dielectric cure monitoring, and robotic proximity sensing [1, 2]. Only surface features can be examined on metallic plates because the accumulation of surface charges blind the capacitive probe to interior features. In dielectric materials, both surface and subsurface features can be examined.

Touchless proximity switch for railway installations

Abstract: A contactless proximity switch remotely fed via a two-wire line should also properly signal inferences of very short duration by means of current pulses of a predetermined minimum duration with little current consumption. The contactless proximity switch consists of a sensor (SR), the electrical behaviour of which can be influenced by metal parts and the sensor voltage (US) of which, which can be changed when influenced, controls an electronic threshold switch (OP) which also emits pulses of a predetermined minimum length (t2/t4) with influences of only very short duration due to a special external circuit (C1, R4, D2). The contactless proximity switch is advantageously used as wheel sensor in railway signal systems in which high travelling speeds must be expected.