Abstract: The present application relates to a technical field of determining an irreversible demagnetization of a grain boundary diffusion NdFeB magnet, and more particularly, to a method for identifying an irreversible demagnetization of a grain boundary diffusion NdFeB magnet by magnetic field distribution. After applying a reverse magnetic field to a saturatedly magnetized grain boundary diffusion NdFeB magnet, if a number of magnetic poles on a non-diffusion face of the grain boundary diffusion NdFeB magnet is increased, it is determined that there is an irreversible demagnetization in the grain boundary diffusion NdFeB magnet.

Abstract: A metallurgical device, in particular a casting installation, rolling mill or strip processing installation, including at least one machine part rotating about an axis, wherein an energy consumer that is in electrical connection with an energy source is arranged in the machine part. To supply the energy consumer with energy on a sustained basis in spite of adverse ambient conditions, the energy source is designed as a generator which is in connection with the rotating machine part for rotation therewith, wherein the generator is otherwise free of any mechanical connection with the metallurgical device and wherein the generator has a housing element, on which at least one eccentric mass arranged at a location that is at a distance radially from the axis.

Abstract: The present invention relates to kits and methods for calibrating a pump through performance of a thermal knockdown process including demagnetization of an impeller of the pump where the impeller is separate from the pump. By heat treating the impeller, a property of magnetic interaction of the pump is reduced in a repeatable manner. A kit includes a pump with impeller, a controller and an oven. The method generally involves an iterative process of testing the pump for a property related to magnetic interaction of the elements of the pump, removing the impeller from the pump, heating the impeller under controlled conditions, then placing the impeller back into the pump to repeat the test performed initially.

Abstract: A pressure sensor is provided with a cylindrical body made of a magnetostrictive material and configured to be deformed under a pressure of a fluid flowing inside and a detection portion configured to detect a change in magnetic field caused by distortion of the cylindrical body. The cylindrical body is provided with a peripheral wall portion curved or bent in an axial direction of the cylindrical body.

Abstract: A sensor arrangement includes a sensor element and a magnet module. The sensor element is configured to measure a magnetic field and is positioned within a shaft. The shaft is configured to shield the magnet module and the sensor element. The magnet module is configured to generate the magnetic field. The sensor element is at least partially positioned within the shaft.

Abstract: A magnetic sensor device includes magnetic detection elements arrayed along a line intersecting the relative movement direction of a medium, and a magnet applying a bias magnetic field to the magnetic detection elements with a line of magnetic force in the constant direction. The magnetic sensor device detects a magnetic field change when a medium with a magnetic pattern passes through the bias magnetic field as an electric signal through the magnetic detection elements and reads the magnetic pattern of the medium. A plurality of reading switches is connected to the respective magnetic detection elements and an output line common to the magnetic detection elements. The magnetic sensor device includes a shift register closing the reading switches sequentially one by one to transfer the outputs from the magnetic detection elements sequentially one by one to the output line.

Abstract: A substrate having rod-like molecules on a surface thereof including: a substrate in which a pattern including a convex portion with a flat upper surface is formed on at least a portion thereof; and a plurality of rod-like molecules, which are formed into rod-like shape, are aligned in line in a direction crossing a molecular length direction of each of the rod-like molecules an the upper surface of the convex portion, and have liquid crystalline states, wherein the molecular length LR of the rod-like molecule is 2.0 or less times LN, which is a length of the rod-like molecule in the molecular length direction within the convex portion; and a method for producing a substrate having rod-like molecules on a surface thereof.

Abstract: A magnetic linear position sensor includes an array of N number of magnets. The array of magnets is distributed along a line to form a magnetic field relay along the line. The sizes and positions of the magnets in the array of magnets are symmetric along the line, and the size of the magnets decreases from the sides of the array of magnets towards the center of the array of magnets. The magnetic linear position sensor further includes a magnetic field sensor spaced apart and positioned above the array of magnets. The magnetic field sensor moves back and forth over the array of magnets to sense the magnetic field of the array of magnets.

Abstract: The present application discloses an integrated circuit comprising a circuit portion (100) coupled between first and second power supply lines (110; 120); a first switch (115, 135) coupled between the first power supply line (110, 120) and the circuit portion (100) for disconnecting the circuit portion from the first power supply line during an inactive mode of the circuit portion; and an arrangement (315, 335, 410) for, during said inactive mode, providing the circuit portion (100) with a fraction of its active mode power supply at least when averaged over said inactive mode to prevent the circuit portion voltage to drop below a threshold value. The present application further discloses a method for controlling such an integrated circuit.

Abstract: Provided is a coercive-force specifying apparatus capable of creating a demagnetization curve for each divisional area of a coercive-force distributed magnet without breaking the coercive-force distributed magnet and of specifying an average coercive force for each divisional area precisely. A coercive force specifying apparatus of the present invention includes: a yoke including an insertion space into which a coercive-force distributed magnet is to be inserted; a magnetizing coil; a search coil that detects a magnetization change when the magnetic field is applied to the coercive-force distributed magnet; and a tracer that creates a demagnetization curve on a basis of a voltage value generated due to the magnetization change. The end face is provided with two or more loop-shaped thread grooves bored therein, the search coil being provided in each thread groove.

Abstract: A method for analyzing an operating point of a permanent magnet performs electromagnetic field analysis based on a B-H curve of the permanent magnet and element data concerning a finite number of elements into which the permanent magnet is divided to obtain the operating point of the permanent magnet. The method includes the steps of storing data of inputted B-H curve; obtaining magnetic flux densities and magnetic fields in plural regions of the permanent magnet by performing the electromagnetic field analysis based on the data of the B-H curve; and obtaining the operating point of each of the elements based on the result of the electromagnetic field analysis by employing a variable, the variable continuously varying in a first quadrant, in a second quadrant, in a third quadrant, and over these quadrants of the B-H curve and linearly varying with respect to the magnetic flux density and magnetic field.

Abstract: A magnetic field measuring device includes a support base, a measuring mechanism, and a displacement sensor. The measuring mechanism is positioned on the support base, and includes a mounting plate, a swing arm, a connecting member, an elastic member, and a measuring magnet. The mounting plate is connected to the support base. The swing arm is rotatably positioned on the mounting plate. The elastic member is positioned between the connecting member and the swing arm. The measuring magnet is connected to the swing arm, opposite to the support base. The displacement sensor is positioned on the support base, opposite to the swing arm.

Abstract: Provided are an apparatus and a method for diagnosing permanent magnet demagnetization of a permanent magnet synchronous motor. The apparatus includes a magnetic field generating unit, a stator current measuring unit, and a demagnetization diagnosing unit. The magnetic field generating unit generates magnetic fields of which directions are respectively parallel to a predetermined direction among a plurality of directions passing through a rotation axis of a rotor, on a plane vertical to the rotation axis of the rotor which is in a standstill. The stator current measuring unit measures currents which flow in a stator winding in correspondence with the respective generated magnetic fields.

Abstract: There is provided a coercivity performance determination device for a coercivity distribution magnet that is capable of determining, in a short period of time, with precision, and at as low a testing cost as possible, whether or not each part of one coercivity distribution magnet has a coercivity that is equal to or greater than the required coercivity. A coercivity determining device of the present invention comprises: a substantially C-shaped magnetic body; excitation means that generates a magnetic flow in the magnetic body; and a flux meter that measures the residual magnetic flux of the coercivity distribution magnet. Protrusions are provided at corresponding positions on two opposing end faces of the magnetic body, and the coercivity distribution magnet is held between the two protrusions to form an annular magnetic circuit. An external magnetic field generation means is formed by magnetic regions caused by the protrusions and non-magnetic regions comprising the air in the periphery thereof.

Abstract: According to the present invention, a method for determining coercivity of a coercivity distribution magnet, whereby coercivity of each portion in the coercivity distribution magnet can be determined with good accuracy without, for example, cutting the coercivity distribution magnet into pieces and thus quality assurance can be achieved with good accuracy, is provided.

Abstract: The present invention relates to magnetic anchorage equipment comprising a frame able to contain a plurality of polar units, each of the plurality of polar units having a ferromagnetic polar element which identifies an anchorage surface and a self-testing unit for checking the magnetic equipment. The magnetic anchorage equipment is characterized in that the self-testing unit for checking the magnetic equipment is at least partly integrated in the frame.

Abstract: A hand-held check fixture to indicate excessive play in a pitch change link ball joint is provided. The check fixture can include a first member for attachment to a first portion of the pitch change link, a second member for attachment to a second portion of the pitch change link, and a gage to indicate movement of the first member relative to the second member. The gage is adapted to indicate the clearance between a pitch change link ball bearing and a pitch change link knuckle in the axial direction and/or in the radial direction. The check fixture can assist in evaluating the flightworthiness of each pitch change link on a rotor assembly with relative ease and without requiring the complete removal of each pitch change link from the rotor assembly.

Abstract: It is possible to perform accurate magnetization analysis by considering the magnetic state of an incomplete magnetic region. A magnetization analysis device performs magnetization analysis by using a magnetizer parameter associated with a magnetizer and a magnet parameter associated with a magnet material so as to calculate a magnetization magnetic field applied to respective portions of the magnet material (S17), calculates a recoil ratio permeability and a coercivity as region of a permanent magnet as an analysis object for the respective portions according to the calculation result of the magnetized magnetic field and the demagnetization curve associated with the incomplete magnetization region actually measured in advance (S18), and performs a magnetic field analysis by using the calculation result of the region parameter so as to calculate a state parameter indicating the magnetized state of the permanent magnet as an analysis object (S19).

Abstract: A method is provided for detecting an insufficient or missing phase current in a permanent magnet synchronous motor, and includes determining a composite vector position of a combined three-phase phase current with respect to a stationary portion of the motor, and assigning a sector to the position. The method includes comparing the phase current to a calibrated threshold current corresponding to the sector, and executing a response when the absolute value is less than the threshold. A vehicle includes an energy storage device (ESD), a motor/generator configured as a permanent magnet synchronous motor, a voltage inverter, and a bus for conducting DC current from the ESD to the inverter. A controller detects an insufficient phase current, determines a current vector position of the three-phase AC, assigns a sector to the position, and executes a response when an absolute value of the phase current is less than a calibrated threshold.

Abstract: A method for estimating the magnetization level of one or more permanent magnets established in one or more permanent magnet rotors of a wind turbine generator includes the steps of: establishing one or more magnetization sensors at the stator of the generator, connecting the one or more magnetization sensors to a measuring mechanism, processing measured data in the measuring mechanism, and establishing values of magnetization. Furthermore the invention also relates to a wind turbine.

Abstract: The present invention relates to magnetic anchorage equipment comprising a frame able to contain a plurality of polar units, each of the plurality of polar units having a ferromagnetic polar element which identifies an anchorage surface and a self-testing unit for checking the magnetic equipment. The magnetic anchorage equipment is characterized in that the self-testing unit for checking the magnetic equipment is at least partly integrated in the frame.

Abstract: It is possible to perform accurate magnetization analysis by considering the magnetic state of an incomplete magnetic region. A magnetization analysis device performs magnetization analysis by using a magnetizer parameter associated with a magnetizer and a magnet parameter associated with a magnet material so as to calculate a magnetization magnetic field applied to respective portions of the magnet material (S17), calculates a recoil ratio permeability and a coercivity as region of a permanent magnet as an analysis object for the respective portions according to the calculation result of the magnetized magnetic field and the demagnetization curve associated with the incomplete magnetization region actually measured in advance (S18), and performs a magnetic field analysis by using the calculation result of the region parameter so as to calculate a state parameter indicating the magnetized state of the permanent magnet as an analysis object (S19).

Abstract: A method for estimating the magnetization level of one or more permanent magnets established in one or more permanent magnet rotors of a wind turbine generator includes the steps of: establishing one or more magnetization sensors at the stator of the generator, connecting the one or more magnetization sensors to a measuring mechanism, processing measured data in the measuring mechanism, and establishing values of magnetization. Furthermore the invention also relates to a wind turbine.

Abstract: A magnet scanning device uses a helical scanning technique to scan a cylindrical magnet along a helical path on a cylindrical surface that corresponds to the cylindrical magnet. Based on the magnetic field profile, the device may detect any unacceptable irregularities in the magnetic field and identify a location of the cylindrical magnet associated with the irregularity.

Abstract: An apparatus and method is provided for measuring magnetic force response time due to the magnetic viscosity of materials and for measuring total energy exchanged due to relative motion of magnetic materials. Voltage and current versus time through an electromagnet is measured and recorded. Corresponding force versus time is measured for magnetic forces applied to a material under test in response to energizing the electromagnet to determine effects of magnetic viscosity of the material under test. A test system is also provided for measuring energy exchanged due to the relative motion of magnetic materials. Absolute values of transferred mechanical energy and electrical energy are combined to determine the total energy exchanged by interaction of a permanent magnet and an electromagnet.

Abstract: A method is provided for preserving the transverse biasing of a GMR (or MR) read head during back-end processing. In a first preferred embodiment, the method comprises magnetizing the longitudinal biasing layers of the read head in a transverse direction, so that the resulting field at the position of the transverse biasing layer places it in a minimum of potential energy which stabilizes its direction. The field of the longitudinal biasing layer is then reset to the longitudinal direction in a manner which maintains the transverse biasing direction. In a second embodiment, a novel fixture for mounting the read head during processing includes a magnetic portion which stabilizes the transverse bias of the read head. The two methods may be used singly or in combination.

Abstract: A multiple operation type input device includes: an operating body that is integrated with a rotating shaft A plurality of permanent magnets are provided on the operating body at the same interval in the circumferential direction thereof. A frame supports the rotating shaft. Sliders support tilting shafts of the frame; holders that supports the sliders such that the sliders can be moved in the vertical direction. A cam member is fixed to the rotating shaft. A steel ball is engaged with or disengaged from the cam member during a rotating operation, and keeps the operating body at an intermittent rotation position when the operating body is not operated. A magnetoresistive element detects a magnetic field intensity of the permanent magnets. A determining unit determines the operational state of the operating body on the basis of signals output from the magnetoresistive element.

Abstract: A magnetic position sensor has a stator (16?, 36, 52) formed of magnetic material and a pair of magnets (14a, 14b; 34a, 34b; 54a, 54b; 64a, 64b) rotatably mounted about the stator and movable between opposite angular extremities and spaced from the stator by a primary cylindrical air gap (5). A secondary air gap (4) is formed in a stationary member at a location at which the magnetic field varies with the angular position of the magnets. A first Hall Effect sensor (18) is disposed in the secondary air gap to measure the magnetic field there-across as an indication of the angular position of the magnets. A second reference sensor (22) is provided to detect the magnetic decay of the magnets. The second sensor can be a Hall Effect sensor disposed at a location at which the magnetic field is relatively constant, independent of the angular position of the magnets. The reference sensor output can be used as a diagnostic indicator or as a correction for the first sensor output.

Abstract: A method for balancing the flux density of a permanent magnet includes sensing flux density in a permanent magnet and if unbalanced relative to a physical center, adjusting the cross-sectional area and shape of the magnet by removing magnetic material from the magnetic pole with the stronger magnetic flux density. This method is repeated until the magnetic flux density is balanced between the opposite poles of the permanent magnet relative to the physical center.

Abstract: A sensor assembly for sensing angular position of an object is provided. The assembly may comprise at least one magneto-sensing magnet having a second axis of rotation. The assembly may further comprise a magnet having a second axis of rotation. At least one of the magnet and the magneto-sensing element are rotatable relative to the other. The respective axes of rotation of the magneto-sensing element and the magnet are non-coincident with respect to one another. The magnet is magnetized along one of the following directions: an axial direction and a radial direction.

Abstract: A device and a method for determining a magnetic field with respect to its intensity and direction at at least one detection location, and uses a first arrangement for superimposing an auxiliary magnetic field, known at least in intensity, on the magnetic field, and a second arrangement for measuring at least the direction of the magnetic field resulting from the superimposition of the magnetic field to be determined and of the auxiliary magnetic field at the detection location. The magnetic field is determined at the detection location in that the resultant magnetic field produced by the magnetic field to be determined and the auxiliary magnetic field is determined with respect to its direction for at least two different auxiliary magnetic fields; and the magnetic field to be determined is calculated therefrom. The method is especially suited for determining the intensity and direction of a magnetic field in the immediate vicinity of the surface of a magnet.

Abstract: An apparatus for measuring the magnetic field distribution of a magnetic sample includes a magnetic field sensor arrangement having three, orthogonally-disposed, Hall sensors for sensing the magnetic field produced by a magnetic sample at a given location, The sensor arrangement is scanned along a predetermined scan pattern. The apparatus then acquires sampling data from the sensor arrangement, the sampled data providing a representation of the magnetic field distribution of the magnetic sample. The data is preferably acquired by an interface card for a PC, which stores sampled data in the main memory of the PC for data analysis and display.

Abstract: An apparatus and method that tests an NMR system, including MRI scanners, by taking H-B measurements for the apparatus at any stage during the manufacture thereof, to thereby detect any defects of the NMR system at any point during the manufacture thereof.

Abstract: A method and apparatus for determining remanence and coercivity of high strength rare earth magnets, without full determination of their hysteresis characteristics and subsequent computation, enables high speed, high throughput testing of such magnets in a production facility. The magnets are first fully magnetized by capacitor discharge through a pulsing magnetizing coil, if not already fully magnetized, and their remanence can be noted at zero applied field. Then the magnets are progressively demagnetized, again by capacitor discharge through a pulsing coil, and, with the state of magnetization of the magnets and the strength of demagnetizing field continuously monitored, note is taken of the strength of the demagnetizing field when the magnetization of the magnet is reduced to zero. Based on this sole measurement, the coercivity of the magnet is derived.

Abstract: A flux sensitive device for creating electrical signals from magnetic flux produced by a magnetic piece has a first member defining a surface for sliding the magnetic piece. A conductive trace and a backiron are located proximate the first member such that the conductive trace is between the first member and the backiron. The position of the conductive loop is fixed relative to the backiron and the first member. The backiron forms a magnetic flux path with the magnetic piece and the conductive trace creates an electrical signal when magnetic flux crosses the conductive trace.

Abstract: A bipolar magnet as used in magnetic disk drives is characterized by measuring field strength of the magnet along a plurality of radii using a Hall effect sensor which is incrementally indexed across the magnet by a stepper motor. The gap field strength, pole transitions, and null zone can be determined from combinations of the measurements along the plurality of radii.

Abstract: Apparatus for characterizing the magnetic field of a device under test includes a device for nullifying the ambient magnetic field in a test environment area with a constant applied magnetic field, a device for rotating the device under test in the test environment area at least nearly through a complete circle, a device for sensing the magnetic field at a sensor location which is along the circumference of rotation as a function of the rotation angle for successive ones of a set of predetermined orientations of the device under test to obtain a profile of the magnetic field at the sensor location as a function of the rotation angle for each one of the predetermined orientations, a memory for storing the profiles, and a processor coupled to the memory for characterizing the magnetic field of the device from the magnetic field profiles thus obtained.

Abstract: A method for coupling liquid crystals and a magnetic field to monitor changes in local magnetic properties (e.g., direction of magnetization) is provided. A magneto-optical sensor is used to detect and observe inhomogenieties, impurity phases, of a high energy magnet by monitoring the response of liquid crystals to a magnetic and/or electric field applied perpendicular or antiparallel to the magnetic field supplied by the magnet. The intensity of field necessary to cause a rotation of the liquid crystals in the direction of the applied field, and hence a modification of the optical properties of the liquid crystals, can be used as a rapid, inexpensive quality control test for batch magnet fabrication. The method can be applied to both thin films and bulk specimens. The magnetically weak spots of the sample can be mapped out by noting the appearance of dark and light regions as the liquid crystals are rotated into positions which obscure the illuminating light.

Abstract: A method for determining force characteristic of a device for magnetically holding workpieces placed on a top plate (3) of the device, wherein a workpiece (1) cooperating with a source of magnetic field of the device is connected to a force pick-up (2) and is caused to move along the top plate (3), along a test line (4). The source of magnetic field remains permanently energized during the tests, the workpiece (1) is placed in parallel with the top plate (3) with a clearance which depends on sensitivity of the force pick-up (2), and is caused to move along the test line (4) continually while maintaining the amount of the clearance substantially unchanged.

Abstract: A description is given of a pulse device for zeroing a permanent magnet to any desired operating point on its demagnetization curve, in which the strength of the demagnetizing pulse is automatically determined from the ratio between the operating point reached and the desired operating point.

Abstract: To test magnetic elements, by integrating output signals derived from a sensing coil to which the magnetic elements are exposed, by being passed therethrough, the output signals are additionally applied to a threshold switch, which activates the integrator only if (a) the output signals exceed a given threshold, and (b) they are in a predetermined polarity, so that the integrator will not integrate first in one and then in reverse direction, thus providing no useful output signals. The system is simple and avoids the necessity of special circuitry.

Abstract: Bodies of a ferrimagnetic material are disposed within small cavities provided in a magnetometer. The magnetometer is initially calibrated utilizing an electromagnet to produce an applied magnetic field of either known field strength, H.sub.DC, or known field distribution. Radio frequency energy is fed equally to each cavity and each material and results in resonance frequency output signals which may be coupled to a visual display. When the calibrating magnetic field is of known uniform strength, H.sub.DC, the orientation of the bodies is changed until each of the resonance signals have a frequency substantially given by f.sub.c =.gamma.H.sub.DC where .gamma.=2.8 MHz/oersted. When the calibrating magnetic field has a known field distribution the orientation of bodies is changed until such resonance signals have frequencies related to one another in accordance with the relative magnetic field strengths passing through the cavities.

Abstract: There is disclosed a technique for measuring the magnetic field of a sample, such as sheet material having one or more magnetic poles, including effecting relative movement between a magnetically responsive transducer and the sample to scan the magnetic field while controlling the distance between the transducer and sample. Apparatus is provided to practice such technique, including control of the relative scanning movement, and of the transducer/sample spacing. A breakaway support for the transducer prevents damage in case an obstruction is struck, and a circuit operates on the analog signal produced by the transducer to provide useful output information representative of the magnetic field.

Abstract: Bodies of a ferrimagnetic material are disposed within small cavities provided in a magnetometer. The magnetometer is initially calibrated utilizing an electromagnet to produce an applied magnetic field of either known field strength, H.sub.DC, or known field distribution. Radio frequency energy is fed equally to each cavity and each material and results in resonance frequency output signals which may be coupled to a visual display. When the calibrating magnetic field is of known uniform strength, H.sub.DC, the orientation of the bodies is changed until each of the resonance signals have a frequency substantially given by f.sub.c =.gamma.H.sub.DC where .gamma.=2.8 MHz/oersted. When the calibrating magnetic field has a known field distribution the orientation of bodies is changed until such resonance signals have frequencies related to one another in accordance with the relative magnetic field strengths passing through the cavities.

Abstract: An apparatus for testing enclosed electromagnetic relays includes a probe displaceable into the relay enclosure to engage the movable contact thereof. The probe is associated with a force transducer and a displacement transducer which provide inputs to a circuit including microprocessor unit which operates to detect the probe force required to break contact between the movable contact and the normally closed contact and to detect the position of the probe when such break occurs and when the normally open contact is made and to calculate the contact travel from the position signals it receives. Contact over travel is also measured by applying current to the relay winding and measuring probe displacement required to re-engage the contact.

Abstract: Apparatus for testing permanent magnets such as in a generator or alternator embodied in a fly wheel. The apparatus includes a testing head on which the fly wheel is placed for the purpose. The fly wheel has a circular series of permanent magnets, and the head has a corresponding circular series of electro magnets, with Hall Generators between the electro-magnets, the Hall Generators having an element (bismuth) the resistence of which is affected by a magnetic field. The apparatus includes an electrical circuit embodying the Hall Generators, and the electro-magnets are charged, and the voltage set up through the Hall Generators indicates the voltage condition of the permanent magnets and is the voltage which is tested by the apparatus. The apparatus can also be used for motors as well as generators and alternators.

Abstract: What is disclosed is an apparatus for measuring the relative magnetic field strength of magnetic workpieces such as miniature permanent magnet rotors which, for example, are included in miniature watch motors. The apparatus includes a nonmagnetic shaft member, one end of which is attached to a motor and the other end being positioned in a bearing. The shaft has a reduced portion thereof extending beyond the bearing and located between the poles of an electromagnet which acts as a miniature alternator. Located in the end of the shaft opposite the motor, are inserts for receiving the magnetic workpiece which may be a basic rotor or a rotor/axle assembly. The shaft is rotated at a speed which produces an alternating magnetic field in the electromagnetic pole pieces thus generating an alternating current voltage. This voltage is measured on a digital volt meter or the like with maximum and minimal levels established by calibrating with good and average rotors.

Abstract: A method and apparatus for setting the relative magnetic relationship between a Hall Effect switch with a given operating field strength and a permanent magnet to operate the switch and having a magnetic field with a field strength greater than the operating field strength. This invention can be used for adjusting the toggle point of a combined Hall Effect switch and magnet or the dwell between the operate point and release point of the switch. This method or apparatus comprises the steps of determining the actual switching point or dwell of a combined Hall Effect switch and operating magnet, which switching point or dwell is controlled by the combination of the field strength of the magnet and the operating field strength of the switch, determining the difference between the actual switching point or dwell and a desired switching point or dwell and then modifying the magnetization of the permanent magnet to shift the actual switching point or dwell toward the desired switching point or dwell.

Abstract: An element together with a prospective shunt load is magnetized to become a permanent magnet whereafter the magnet is stepwise demagnetized, actually along the demagnetization curve but due to load along a load line passing through a point inside the demagnetization curve independently from any variations thereof. This point will serve as operating point of the magnet in the system and the load line is characterized by identifying the operating point establishing a minimum induction on the basis of the shunt so that during normal operation of the magnet in a system smaller flux will not be extracted. The demagnetization steps are tracked by interspersed measuring steps to monitor approach of the desired operating point. The system is preferable a relay and magnetization, demagnetization, measurement and termination are carried out in a different, closed loop system.

Abstract: The present disclosure describes apparatus for the production of small permanent bar magnets accurately adjusted to a stable, predetermined value of magnetic moment. In accordance with the invention, the readout of the moment of the magnet under adjustment is provided simultaneously with the degaussing process, so that the operation becomes a coordinated one rather than the present day process involving trial-and-error. The system provides easily obtainable time-saving consistent results and is especially useful where large numbers of magnets of predetermined moment must be produced. The real-time sensing capability of the system renders it particularly suitable for automation.