Abstract: The inductance value of air-core coils are adjusted using automated methods and inexpensive, noncomplicated apparatus. Adjusting tools are provided which displace coil turns in a linear motion with respect to the coil centerline. Specifically, the coil turns can be displaced by sliding perpendicularly to the coil centerline or by rotating a group of coils in order to modify the coil inductance. The adjusting tools used and the method of coil-turn displacement allow the automated method to reincrease the inductance of a coil in the event that displacement causes an over-decrease of inductance.

Abstract: A magnetoelastic force-measuring device is proposed which has an annular thrust body possessing magnetostrictive properties and bearing a ring coil. To enhance the measuring sensitivity in conjunction with simultaneous good thermal error compensation, a sleeved tension body, likewise possessing magnetostrictive properties and bearing a ring coil, is arranged coaxially in the annular thrust body to fit in such a way that, given the introduction of a force, the one body is subjected to thrust and the other to tension. In this connection, the magnetostrictive properties are formed by a soft magnetic measuring film--preferably of amorphous metal--which applied in each case to the body, and the two ring coils are connected up to make an inductive half-bridge.

Abstract: A transducer for object examination comprises a conductive member of generally disc-shape having an opening of generally triangular configuration extending from the periphery of the member toward its center with opposed sidewalls of the opening in nonparallel relation to one another. A winding is applied to the perimeter of the conductive member and spans the opening. In certain instances, the transducer winding defines successive courses in each turn thereof which are of respective different diameter.

Abstract: A unitary tuning structure of a UHF tuner includes an inductance loop, an inductance adjustment element attached to a top portion of the inductance loop so as to be foldable with respect to the inductance loop about an axis parallel to the printed circuit board to which the inductance loop is attached and a capacitance adjustment tab attached to a side portion of the inductance loop so as to be foldable with respect to the inductance loop about an axis perpendicular to the printed circuit board. In another form of the unitary tuning structure, a second inductance loop can be attached within the first loop.

Abstract: A magnetic field sensor coil wherein the coil is formed into a shape comprising two generally C-shaped limbs (2, 3) one within the other, one of these limbs being covered by a magnetic screening material (4). In operation an e.m.f. is induced in each turn of the unscreened part of the coil (3) while no e.m.f. is induced in the screened part (4) and so the total e.m.f. induced is approximately equal to the e.m.f. that would be induced in a simple concentrically wound coil of the same number of turns and of the same dimensions as the unscreened portion of the coil. The coil according to the invention is especially suitable for use with a system for monitoring an electric motor where the coil may be placed adjacent the motor end plate concentrically around the motor shaft without having to uncouple the motor from its load.

Abstract: A current controlled inductor (1) having an inductor coil (4) in one state of alteration attached at one end to a displacing coil (6) in an opposite state of alteration to that of the inductor coil (4). Both coils are formed of a shape memory alloy that when heated to a predetermined temperature will return to an original configuration from an altered configuration. An electric current from a DC source (11) passing through the displacing coil (6), heats the displacing coil (6), causing the coil to contract to an original length and simultaneously pull the inductor coil (4) from its original length thereby changing the inductance effect of the inductor coil (4) on the signal source (12).

Abstract: A thin-film type electromagnetic transducer formed on a nonmagnetic substrate by a thin-film forming process. The transducer includes a magnetic core formed on the substrate by the thin-film forming process, and a conductor coil formed on the substrate by the thin-film forming process, so as to be wound around the core. The core is shaped so that a leakage flux generated along the plane of the substrate is greater than that generated in a direction intersecting with the plane of the substrate, the leakage fluxes being generated from the core when a current is supplied to the coil. In a method for transferring signals from the thin-film type electromagnetic transducer described above, a magnetic head is located so as to face that region of the core of the transducer where the maximum leakage flux is generated.

Abstract: A magnetoelastic force transducer is made of two identical, cylindrical bodies of magnetic material which are held together by means of a stud bolt. In an axially extending and concentrically located inner space there is placed a bobbin with two measuring windings connected in opposition and an excitation winding supplied with alternating current. The interior of the transducer is shaped such that a thin cylindrical tubular wall is formed immediately opposite to the respective measuring winding in each one of the bodies. When the transducer is force-loaded via the stud bolt, a compressive stress arises in one of these tubular walls and a tensile stress arises in the other tubular wall. This influences the magnetic conditions such that a signal is obtained from the measuring windings which is proportional to the applied force.

Abstract: A fluid pressure sensor includes a body made of a soft magnetic material with a groove formed therein, and a coil is installed in the body in the groove. One magnetostrictive disc is placed on the body over the groove, and two non-magnetic discs are placed over the magnetostrictive disc. A casing is provided for accommodating the body carrying the coil, the magnetostrictive disc, and the non-magnetic discs, and it is closed by a lid member which has a surface for receiving a fluid pressure. A plurality of through holes are formed in the lid member within the fluid pressure receiving surface such that the through holes extend to the non-magnetic disc at position over the groove, whereby the magnetostrictive plate is partially distorted by the fluid pressure.

Abstract: Contactless inductive power transfer from a stationary "reader" to energize the electronics on a portable data or "smart" card is made practical through a flexible inductor carried on the card. The inductor, which acts as the secondary portion of a power transformer, comprises a flat coil and a flexible magnetic but nonmagnetostrictive core piece. The core piece may be a thin wafer of amorphous magnetic alloy. Clock pulses to synchronize data transfer on the card with the reader can also be generated from the signal picked up by the inductor.

Abstract: A magnetic amplifier employing a single four-legged ferrite core having orthogonally disposed through holes in the core. Biasing is provided of the magnetic core so as to provide operation in the non-linear parts of the core's hysteresis cycle. A first coil on the ferromagnetic core has an AC excitation signal applied thereto and a second coil on the core is wound orthogonally to the first coil and is adapted to have an output signal derived therefrom. A control or input current in a third coil is used to unbalance the magnetic bridge formed by the four legs, so as to produce a mutual inductance different from zero between the first and second coil. The biasing may be provided by a fourth coil or by permanent magnet means.

Abstract: A method for converting a movement into an analog or digital variable, in particular into an electrical voltage, and an apparatus for performing the method are proposed. The apparatus includes at least one measuring spring element having windings and fabricated of electrically conductive material, which is disposed together with a supplementary spring element of identical structure and serving as a supplementary resistor in a bridge branch of a carrier-frequency measurement bridge. A deformation of the measuring spring element by a movement causes a change in the spacing between windings and thus causes a change in the inductive resistance of the measuring spring element which serves as a standard for the movement.

Abstract: A stress or strain sensor including a magnetic circuit having at least a part constituted by an amorphous magnetic alloy. For detection of the inductance value of the sensor, a DC magnetic field is superposed on an AC magnetic field so that magnetic domains of the alloy tend to be aligned. The sensor output can be increased significantly over that of the conventional sensor in which only the AC magnetic field is employed, while hysteresis of the output is reduced. The temperature characteristic is also improved.

Abstract: A device for sensing pressure at a source thereof comprising a housing with a fluid pressure responsive diaphragm movable therein for defining therewith an expansible chamber for communication with the source of pressure the magnitude of which is to be sensed, and a transducer. The transducer includes a body of magnetoelastic material of generally annular form positioned within the housing and having magnetic properties which vary as a function of the stress to which the body is subjected in response to movement of the diaphragm. Electrical circuitry responds to stress-induced changes in the magnetic properties to produce an electrical signal having a value which is a function of the magnitude of the fluid pressure. The device includes an actuator, which is movable with the diaphragm, for accepting and retaining a sector of the annular body and a cradle generally fixed in relation to the housing for accepting and retaining a diametrically opposite sector of the annular body.

Abstract: An adjustable signal coil, for example a solenoid, saddle or Helmholz type of signal coil which is used in a nuclear spin or NMR examination assembly, includes a pair of adjustable conductor guide and profile supports which hold one or more turns of a conductor forming the signal coil. The coil volume is changed by adjusting the supports to correspond to different sizes of targets to be positioned and examined inside the coil. In a disclosed embodiment, the coil volume is cylindrical and has its diameter changed by adjusting the spacing between the pair of supports, and the coil turn length and size, are adjusted by sliding guides within guideways of the supports.

Abstract: A system and method for adjusting the frequency of operation of a radio frequency circuit including an inductive loop having an adjustable exposed inductor portion is provided. The frequency of operation of the circuit is first detected with means for detecting a parameter relating to and representing the frequency of operation. The adjustable inductor portion is associated with a selectively movable actuator device coupled to the frequency detecting means and a source of signals representing a predetermined frequency of operation for the circuit. A control circuit means, preferably a computer, is coupled to the detecting means and to the source of signals to provide an output control signal when the detected frequency of operation bears a predetermined relationship to the predetermined frequency of operation.

Abstract: A magnetoelastic transducer comprises a plurality of sheets assembled together into a sheet package, the sheet package being provided in known manner with at least one excitation winding and at least one measuring winding. The sheet package comprises first sheets of non-magnetic material of austenitic steel, interleaved with second sheets of compound type, each of the sheets of compound type comprising an inner core layer of magnetic material, for example silicon steel, metallically connected on each of its sides to a respective outer layer of non-magnetic material of austenitic steel.

Abstract: A pressure sensing unit for a pressure sensor using the magnetostriction effect of a ferrous amorphous magnetic alloy having elasticity which permits magnetostriction, and including an inductance element which has a magnetic core formed at least in part of the amorphous magnetic alloy and which is subjected to pressure so as to exert pressure on the alloy corresponding to the pressure to be measured, the resulting change in the value of the inductance being used to detect the applied pressure.

Abstract: A coil device for use by divers in subjecting an elongate underwater strure member to a magnetic field for inspection purposes includes a framework supporting a winding having first and second coaxial coils of predetermined coil diameter that lie in substantially parallel planes separated axially by a distance at least twice the coil diameter, the coils being electrically connected in series so as to generate magnetic fields of opposite polarity. The coils, connecting conductors, and framework are adapted to be spread open and closed around the member to be inspected.

Abstract: 1.

Abstract: A rolled core is formed by winding a thin body of an amorphous magnetic alloy having positive magnetostriction characteristics so that, of the two surfaces the surface of smaller surface coarseness faces inward. This rolled core is improved in iron loss over a rolled core obtained by winding the thin body so that the surface of greater surface coarseness faces inward. Breakage of the thin body tends to occur less frequently when it is wound so that the surface faces inward.

Abstract: Apparatus for measuring power consumed by a load connected via mains to a source of alternating current having a given fundamental frequency includes means for generating a first signal proportional to the instantaneous voltage across the load and a transformer secondary toroidally wrapped around one of the mains for generating a second signal proportional to the instantaneous current through the load. Tuned amplifiers of narrow band pass amplify the signals before they are fed to a square low multiplier means including photooptical devices.

Abstract: Disclosed is an apparatus for adjusting an inductor that is mounted on a circuit board. The inductor is of the type comprising two extensible sections connected at one respective end to the circuit board and connected at the other respective end by a connecting portion integral to the inductor. The electrical value of the inductor is adjusted by mechanically engaging the connecting portion between first and second push rods and moving the connecting portion so as to simultaneously extend or compress the two extensible sections. The first push rod extends through an opening in the circuit board to apply mechanical force against the connecting portion and the second push rod extends from above the circuit board so as to clamp the connecting portion between the first and second push rods.

Abstract: A pressure-sensitive device is proposed which includes an electrically conducting element in the form of a loop, a screen arranged outwardly of the loop, and a resiliently compressible, non-conducting material between the screen and element, the arrangement being such that, on the application of a loading to the screen, the electrical inductance of the loop is changed, such change being sensed by a reactance-dependent detecting circuit (DET) connected therewith.

Abstract: A member of a linear position measuring transducer is provided with a hole running parallel to its windings. In one embodiment, elements are inserted into the hole to expand or shorten the length of the transducer. In another embodiment, cutout slots are made between quadrature sections of windings and the elements are introduced into the hole to alter the relative spacing between these quadrature winding sections.

Abstract: To measure small displacements, for example displacement of a membrane under change of pneumatic pressure applied at opposite sides thereto, a ferromagnetic wire is stretched between a fixed support and the membrane. An exciter coil, connected to a source of alternating current of suitable strength cyclically reversely magnetizes the ferromagnetic wire. A pick-up coil is electromagnetically coupled to the wire to sense the change of magnetization thereof which will be in the form of sharp needle pulses as the magnetization of the wire changes, the pulse amplitude and pulse width being highly dependent on the strain in the wire and hence on the deflection of the membrane. The wire may be stressed under tension.

Abstract: The invention comprises a plurality of intrusion detection transducers connected together wherein each transducer has a central core extending along an axis and having a length along that axis defined as XL where X is an even number of at least two and L is a given length. At least one sensing winding wire is wound around the core to provide a first-hand winding of L/2 length, X-1 number of windings of length L, and a second end winding of L/2 length, each adjacent winding being a reverse polarity to the next adjacent winding. Means are provided to connect each transducer to the adjacent transducers such that the first end of one transducer connects to the second end of the adjacent transducer.

Abstract: A method for measuring stresses or forces by measurement of variations of the magnetic properties of ferromagnetic substances under stress conditions. This is carried out by providing a ring of ferromagnetic material between two parallel faces on or between which the stresses are exerted, the ring defining a magnetic circuit, providing an electric coil within and around the ring, passing a current through the coil and measuring changes in the properties of the current to measure variations in the magnetic properties of the ring.

Abstract: An arrangement for obtaining an electrical signal corresponding to a distance comprising a conductor loop which is adapted to be arranged in a magnetic a-c field with its plane transverse to the field and which is formed into first and second conductor sections. The conductor sections extend from the respective ends of the loop to a stationary member and the arrangement is further provided with a movable adjusting means whose movement corresponds to the aforesaid distance. The adjusting means is arranged so that a first portion of the first conductor section extends from its respective loop end to the adjusting means and a second portion thereof extends from the adjusting means to the stationary member. The adjusting means is further provided with a deflecting means for offsetting the second conductor portion from the first conductor portion.

Abstract: A contactless key switch includes a manually operable actuating element mechanically coupled to a variable inductor fabricated from a resilient conductive material. The variable inductor biases the actuating element in an undepressed position, and depressing the actuating element compresses the variable inductor and changes its inductance. A detector circuit electrically coupled to the inductor senses the change in inductance and provides a signal indicating that the actuating element has been depressed.

Abstract: An apparatus and method for measuring stresses or forces by measurement of variations of the magnetic properties of ferromagnetic substances under stress conditions. This is carried out by providing a ring of ferromagnetic material between two parallel faces on or between which the stresses are exerted, the ring defining a magnetic circuit, providing an electric coil within and around the ring, passing a current through the coil and measuring changes in the properties of the current to measure variations in the magnetic properties of the ring.

Abstract: A transducer including a central core extending along one axis and having a length along the axis defined as xl, where x is at least two and l is any given length. Surrounding the central core are a plurality of n wires, where n is an even integer of four or more. Each of said wires is wound around different portions of the core to form x numbers of coils of a length of l/n. These coils are a distance of l apart, center to center. Appropriate packaging of this transducer permits burial. The ends of the transducer may be connected to electronic analyzing equipment for processing of signals generated by objects approaching the transducer.

Abstract: The inductor coil includes two helical wire coil sections, one within the other. The coil sections are integral at one end of the coil and have terminals at the other end extending parallel to the longitudinal axis of the coil. The coil is wound from a single length of wire on an apparatus which permits winding of one of the coil section around the other section.

Abstract: A cryogenic magnetic field gradiometer is described wherein adjustments of areas presented by a superconducting wire loop, that is confined in a support structure within a cryogenic environment, are adjusted mechanically through wire positioning elements operated by a plurality of parallel shafts extending to the exterior of the environment. In one embodiment the positioning elements are cams that cooperate to position portions of a wire loop, while in another form bell crank levers are used.