Abstract: A submersible current sensor for sensing a current in a submerged conductor includes: a split core current transformer constructed to generate an output representative of the current carried by the conductor, the split core having a first core member, a first winding disposed about at least a portion of the first core member; a second core member; and a second winding disposed about at least a portion of the second core member; and a housing, the housing including: a first housing member constructed to house the first core member and the first winding; and a second housing member constructed to house the second core member and the second winding.

Abstract: A coupled inductor has two pillars that are aligned in a vertical direction, wherein a first coil and a second coil are respectively wound around one of the two pillars, respectively, wherein the bottom surface of winding turns of the first coil and the bottom surface of winding turns of the second coil are separated by a gap, wherein a magnetic material is disposed in the gap and a straight line that is enclosed by each of the first coil and the second coil passes through the two pillars.

Abstract: A system, apparatus, and method for detecting the presence and amount of liquid and/or solid excrement in diapers or other undergarments, using a miniature ultra-low power near-field electromagnetic probe, applicable circuitry, and additional sensor types, that is hand-held or attached to the outside of said garments

Abstract: A connection device for providing both a connection for liquid transport and a connection for the transport of electrical energy is disclosed. The connection device comprises a first part and a second part, which detachably connect to one another such that a first liquid conduit comprised in the first part connects with a second liquid conduit comprised in the second part, and a primary coil comprised in the first part inductively couples to a secondary coil comprised in the second part, wherein the first part further comprises a first electronic circuit electrically connected to the primary coil, and the second part further comprises a second electronic circuit electrically connected to the secondary coil.

Abstract: The invention relates to a rotary transmitter for example for use in machine tools with adjusting tools. The rotary transmitter comprises a stator part (18) and a rotor part (26), each having a respective stator core part (72) and a rotor core part (74), which are separated from one another at mutually facing ends via an air gap, and each having at least one respective power winding (76, 78), which is wound on the stator core part and the rotor core part, in order to transmit power using the transformer principle, and having respective stator and rotor coupling turns (80?, 80?, 82?, 82?), which are associated with one another in pairs, for inductive data transmission. One aim of the invention is to transmit data without interference. A further aim is a low maintenance requirement.

Abstract: Data values representing the (I2+Q2) values are converted to floating-point representations and a histogram of the floating-point numbers is generated. The count for each histogram bin in the histogram is stored in a memory. Each floating-point number acts as an address for a corresponding histogram bin in the memory. The accumulated counts in the histogram bins are then grouped into a desired number of CCDF bins, and the CCDF curve is derived from the histogram data. Grouping the histogram bins into the CCDF bins may include combining one or more histogram bins into a single CCDF bin. Linear interpolation is used to divide a count value in a histogram bin between two CCDF bins when the histogram bin does not align with a single CCDF bin.

Abstract: A non-contact transformer includes a transformer component provided on the floor of a housing, a printed circuit board on the transformer component, and an empty core space is formed within the transformer component wherein deformation of the housing is prevented through a construction that evacuates residual air from the core space when the core space is filled with resin even though both ends of the core space are covered by lid-like parts. A cylindrical end face at one extremity of the primary transformer component is positioned on the bottom plate of the primary housing opposed to the secondary housing, and the printed circuit board is provided on an opposite cylindrical end face which is at the other extremity of the primary transformer component. A passage is formed between the printed circuit board and the primary transformer component to provide a connecting orifice between a core space of primary transformer component and the space external to the primary transformer component.

Abstract: A disk drive comprises a controller (70) that calculates a drive signal for positioning a head at a desired track on the basis of a desired track-position signal and a measured head-position signal, and a drive circuit for driving a voice-coil motor. The drive circuit includes a current feedback amplifier (21) and a voltage feedback amplifier (50), which can be selectively used. The controller (70) is provided with a speed limiter for determining a maximum speed limiting the speed of a head. The voltage feedback amplifier of the drive circuit is used when the head-position signal is unstable or otherwise malfunctioning, and the current feedback amplifier of the drive circuit is used when the head-position signal is normal.

Abstract: A differential pulse transformer having a drive coil (10a) and differential sense coils (10b) are disposed on a planar surface with a target (10e, 10f) movable over the sense coils to cause an imbalance in magnetic field when a large di/dt pulse is generated in the drive coil. A detection circuit senses the imbalance and provides a digital output accurately identifying the position of the target. Coil and target embodiments include relatively small secondary coils and relatively long targets (10b, 10e/10f; 12b, 12e/12f and 14b) and relatively large secondary coils and short targets (16b, 16c; 18b, 18c; 20b and 22b).

Abstract: A noncontact transformer installed on the floor of a housing whereby air entrapment within the resin that fills spaces in the transformer is prevented. A primary transformer component is provided on a lower surface of a primary housing, which is then filled with resin. Primary transformer component includes a core space which is defined by inclined internal wall that extends away from the lower surface to form a widely open end of the core space that is larger than the end at the lower surface.

Abstract: The invention relates to an inductive transformer for transmitting measurement data and/or electrical energy between two components (1, 2) moving relative to one another, with one primary and one secondary transformer part (4, 5), in which a gap is formed between the moving components (1, 2). A slide ring (6; 7), which comprises a plastic with embedded ferromagnetic metal parts is disposed in the gap. And that the metal parts are distributed so nonhomogeneously in the plastic that their proportion, on the end with which it is solidly disposed on one of the components (1, 2), is high and becomes relatively slight toward the end with which it rubs against the respectively other component (1, 2).

Abstract: An electronic linear scale having a reduced offset position transducer that uses at least one coupling loop on a scale to inductively couple a transmitter winding on a read head to one or more receiver windings on the read head. The transmitter winding generates at least one primary magnetic field. The transmitter winding is inductively coupled to first loop portions of the coupling loops by the primary magnetic field. Second loop portions of the coupling loops generate secondary magnetic fields. Each receiver winding is inductively coupled to the second loop portions of the coupling loops by the secondary magnetic fields. At least one of the transmitter winding or the receiver windings is formed in a periodic pattern complementary to the dimensions of the coupling loops. Prescribed winding configurations are used to reduce the effects of extraneous inductive coupling in the device.

Abstract: An induced current position transducer has a multi-tap winding. The multi-tap winding allows for digital interpolation of position to a small fraction of a wavelength, thereby reducing the amount of analog interpolation performed by the transducer electronics. In addition, a multi-tap receiver winding enhances the total output signal strength, thereby allowing a smaller receiver winding length along the direction of the measurement axis. Furthermore, a multi-tap receiver winding exhibits low impedance, thereby improving the output signal time constant. The multi-tap receiver winding of this invention comprises a plurality of receiver winding loops offset with respect to each other along the measuring axis, and electrically connected in series. Preferably, the signal contributions of each loop combine to form a "vector circle".

Abstract: A device for contact-free transmission of electrical energy from at least one power supply to at least one consumer has a first transformer having connected thereto a first current converting device and a second transformer having connected thereto a second current converting device. A first endless, closed-loop electrical conductor is provided for coupling electrically in a contact-free manner the first and second transformers. At least one of the transformers supplies electrical energy to the electrical conductor and at least one of the transformers receives electrical energy from the electrical conductor.

Abstract: A transformer arrangement is provided which has a primary and at least one secondary winding coupled via a movable armature which is outside of the windings. A second transformer can be provided which has primary and secondary windings coaxial with and surrounding the corresponding windings of the first transformer. The armature is tubular and slidable in the radial clearance defined between the windings of the first transformer and the windings of the second transformer.

Abstract: An inductive type proximity switch (S) includes an open-ended loop (L3) adjacent to the inductor (L1, L2) of the parallel resonant circuit of its main (LC) oscillator. A high speed bistate switch (S1) is connected between the ends of the loop (L3). A pulsed input to the switch (S1) causes sequential making and breaking of a connection between the ends of the loop (L3) whereby the loop (L3) functions as a Faraday shield to inhibit mutual inductive linking of the inductor (L1, L2) with an inductor (L4) of a passive (LC) resonant circuit (L4, C4) of a target (T) when the target (T) is in proximity with the proximity switch (S) and the connection between the ends of the loop (L3) is made by the bistate switch (S1).

Abstract: In a screened inductance sensor having a drive winding, a sense winding, and a conductive screen for varying the induced voltage in the sense winding by reason of the eddy currents generated in the conductive screen in the presence of the drive field, a physical barrier is interposed between the region of the sensor in the windings are located and the region in which the screen is located. These regions are fully environmentally isolated from each other by the physical barrier. The construction is especially suited to screened inductance level gauges, in particular for fuel tanks, where the conductive screen is part of a float assembly in contact with the fuel, but the electrical windings are kept dry in a separate portion of the gauge.

Abstract: Side-by-side inductor coils are wound in a single layer around a thin flat tubular frame. The frame has a closed end portion and is mounted on an insulative base sheet. An elongated thin magnetic core is cantilevered from a insulative connecting rod and normally is positioned inside the frame approximately centered between the two coils. The end portion of the connecting rod remote from the frame is secured to the base sheet. The base sheet can be applied to a specimen to be stress tested and is formed to withstand elongation and compression. Lengthwise sliding of movement of the magnetic core in the coil frame due to stress applied to the specimen indicates the strain of the specimen.

Abstract: In a sensor having a drive winding for establishing a forward field, an electrically conductive screen is displaceable relative to a sense winding. In the presence of the drive field, eddy currents are generated in the screen to establish a counter-field opposing the forward field, so that the sense winding is shaded by the screen to a varying extent during relative displacement of screen and sense winding and the voltage induced in the sense winding is accordingly correspondingly varied. Application of a high frequency input to the drive winding results in a modulated output from the sense winding which may be demodulated to provide a signal indicative of screen position relative to sense winding. The position signal may be further processed to provide a speed signal. The sensor may assume a multiplicity of linear or planar, rotational and axial or solenoidal configurations.

Abstract: A liquid level indicator for detecting a liquid level by utilizing the variation inductance of a coil having a core made of an electrical insulating magnetic material and provided inside a winding of the coil. The core may be made by piling a plurality of thin, plate-shaped conductive materials one on another in the cross-sectional direction of the coil so that they are insulated from each other or by winding a conductive magnetic material at least one turn in the form of a roll so that a closed loop current is not formed in the cross-sectional direction of the coil. An eddy current loss of the core so arranged is so small that it can be disregarded. Furthermore, the winding component of the core itself is substantially released in the equivalent circuit of the coil.

Abstract: Herein disclosed is a device for measuring a displacement of a movable member relative to a fixed member by putting the electromagnetic induction into practical use. The device comprises a first coil having first and second coil sections which are coaxially aligned along a common axis, a second coil arranged to establish a magnetic coupling with the first coil and extending along the common axis, and a short circuit ring arranged to establish a magnetic coupling with the first and second coils and movable relative to the same. The winding density of each of the first and second coil sections is gradually decreased from the outside end to the inside end thereof, and the winding density of the second coil is substantially even throughout the length of the same.

Abstract: A variable inductance transducer includes a winding which is wound about a cylindrical former and a tubular member formed from electrically conductive material which is located about the winding and is movable axially relative thereto. The tubular member is provided with a number of apertures along its length in order to improve the linearity of the transducer.

Abstract: An electrical circuit for inductance conductors, transformers and motors is provided wherein two coils of electrically conductive wire are coiled about a bar of magnetizable material such that they are disposed in mirror image symmetrical relation with each other. A tap is connected to one end of each coil to conduct an electrical current thereto to magnetize the bar. A second tap is connected to the other ends of each coil to conduct an electrical current therefrom.

Abstract: In a sensor having a drive winding for establishing a forward field, an electrically conductive screen is displaceable relative to a sense winding. In the presence of the drive field, eddy currents are generated in the screen to establish a counter-field opposing the forward field, so that the sense winding is shaded by the screen to a varying extent during relative displacement of screen and sense winding and the voltage induced in the sense winding is accordingly correspondingly varied. Application of a high frequency input to the drive winding results in a modulated output from the sense winding which may be demodulated to provide a signal indicative of screen position relative to sense winding. The position signal may be further processed to provide a speed signal. The sensor may assume a multiplicity of linear or planar, rotational and axial or solenoidal configurations.

Abstract: An antenna suitable for use in the high frequency (HF) ranges includes a resonator tunable over a predetermined frequency band. The resonator consists of an insulated wire wound over a dielectric rod. Tuning is effected by sliding a metallic sleeve disposed in frictional contact over the wire. A multiplicity of these resonator units may be mounted on a single collar at different angles. Each of the resonator units will respond to a particular frequency. The remaining devices operate as a load on the antenna assembly. The antenna assembly may also be mounted on a conventional mobile antenna by means of an adaptor unit.

Abstract: A planar coil apparatus is disclosed for providing an output signal indicative of a movement between at least a first and a second position. A first stationary planar member has disposed on a surface, a first flat coil configuration which is emplaced thereon by a printed circuit or similar technique. Located adjacent to this coil on the board is a second coil of similar configuration. A drive signal such as that obtained from an AC or pulse source is applied to the input terminals of one of the coils which constitutes the drive coil. A second planar board is positioned relatively congruent and above the first board and has located thereon a closed coil configuration which constitutes a closed coil loop. As this movable board is brought into proximity with the stationary board, magnetic flux is coupled via the loop from the drive coil to the second coil which serves as the sense coil.

Abstract: The variable inductor and the comparison inductor of a semi-differential variable inductance both have a pair of coils magnetically coupled together. The output current of an amplitude-controlled oscillator flows through the series combination of one coil of each pair and the other coil of the comparison inductor is used to supply a signal which is rectified in order to regulate the amplitude of the oscillator. The remaining coil, the other coil of the variable inductor, is rectified to provide an output signal representative of the ratio of the variable inductance to the comparison inductance and also representative of the displacement of the short-circuiting ring of the variable inductance, which is mechanically linked to the control rod of a fuel injector of a diesel engine as required for a system controlling the fuel injector. The oscillator and the rectifiers can conveniently use operational amplifiers of the same type designation.

Abstract: A displacement-measuring transducer has a laminar member displaceable, for example under control of a vacuum actuator, within a housing containing respective pairs of coils spaced part in the displacement direction of the laminar member, which is provided with two apertures spaced apart in the said direction, such that the coupling between the coils of each pair is dependent upon the position of said apertures and, therefore, on the displacement of the laminar member.

Abstract: A contactless travel keyboard has first and second coils with elongated loop portions arranged at each key station so that, when an electrically conductive key element at the station is in a key-up position spaced from the coils, electrical input to the first coil results in magnetic induction of a relatively small output signal of a first polarity in the second coil and so that, when the key element moves to a key-down position relatively closer to the coils, electrical input to the first coil induces a current in the key element to magnetically induce a control signal of opposite polarity in the second coil sufficient to reverse the polarity of the output from the second coil. The keyboard includes means responsive to the reversal in polarity of the output signals from the second coils for determining which keys are in a key-down position.

Abstract: A sintered powdered aluminum core for an inductor used in the tuning stages of high frequency equipment is disclosed. Such cores have threads ground on them having sharp thread profiles, as opposed to the flat thread profiles produced by screw machines, and plating the cores produces superior electrical properties.

Abstract: A core with at least three elongated legs, at least one leg being centrally located among all the elongated legs, is joined at at least one end by a yoke portion connecting all the legs. The central leg or legs is wound with a magnet winding close to the yoke portion of the core, with which the core is excited with an alternating field. A short-circuiting ring structure, which may be in the form of an apertured plate, encircles at least the central leg or legs of the core and is movable in the direction of elongation of the core in accordance with the movement of a body the displacement of which is to be measured. The legs of the core may be bent in order to measure rotational or angular displacement. Movement of the short-circuiting ring along the length of the core varies the inductance of the coil in a predetermined manner, which may be a linear relation to displacement. A yoke and a winding may be provided at the other end in order to increase the sensitivity by a differential method of measurement.

Abstract: An apparatus for detection of the level of a liquid metal is disclosed. The apparatus has a liquid level detecting probe provided with an exciting coil wound in a closed bottom non-magnetic sheath over the approximately whole length thereof, a level detecting coil wound in the sheath in an upper part thereof, and a temperature compensating coil wound in the sheath in a lower part thereof; a temperature control for maintaining the coils at a constant temperature; a drive circuit for supplying the exciting coil with an alternating current of a determined frequency and amplitude; and a signal processing circuit for subjecting output voltages induced in the liquid level detecting coil and in the temperature compensating coil to linear detection and then determining the ratio of the thus detected outputs, thereby detecting the level of the liquid metal.

Abstract: An induction-type meter for measuring mechanical quantities, comprising a first converter to convert the controlled parameter into a displacement and having elements adapted to be moved relative to each other, and a second converter to convert the displacement into an electric signal and including a magnetic circuit with a block of coils mounted on one of the elements capable of relative movement, and a diamagnetic screen mounted on the other element capable of relative movement. The magnetic circuit is embodied as a closed-open loop system comprised of two parallel parts formed by armored cores mounting said coils and arranged to provide a gap accommodating said diamagnetic screen with profiled working edges.

Abstract: Inductive sensing keyswitch includes a printed circuit transformer and sheet of material having hinged metal flaps formed therein and each flap is resiliently biased against both printed circuit coils of the transformer for eddy-current shorting of both coils wherein keys on the keyboard have key stems passing through the printed circuit board between the printed coils and the flap hinges to provide a mechanical advantage for moving the flaps away from the printed circuit coils a greater distance than the short stroke movement of the key.

Abstract: An inductive transducer is provided with a core with legs extending in opposite directions from a yoke on which a coil is wound. On the leg portions extending on one side of the coil a short-circuiting ring displaceable in accordance with the displacement of a body the movement of which is to be measured is provided and on the leg portions extending on the other side of the coil a compensating short-circuiting ring is provided having a mass corresponding to the total mass of the first short-circuiting ring and the movable portion of the body to which it is connected and the connection therebetween. The effect of acceleration forces produces an equal shift of both short-circuiting rings in the same direction, leaving the total flux linking the coil substantially unchanged. The device can be adapted to measure either linear or angular movement.

Abstract: A variable inductor having a U-shaped magnetic core with a short-circuiting plate providing a short-circuiting ring for both legs of the core movable along the core legs in response to a displacement to be measured is connected in an electronic circuit to generate oscillation of a frequency that is either directly or inversely proportional to the displacement. For the inversely proportional case, the variable inductance component can be combined with an integrator function and connected to an operational amplifier, for generation of the output frequency with a small number of electrical components. The thickness and spacing of the core legs are varied along their length to produce a highly linear inductive transducer characteristic. The core legs are bent in a circle when it is desired to measure an angular displacement.

Abstract: An inductor coil consisting of two cores enclosed by a single layer of wire is disclosed. The cores may be of the same or different permeability. The coils arranged in this configuration behave like two coils in series in which the relative values of inductance can be varied independently, thus the change in inductance depends only on the number of turns and the relative permeability of the cores. Decreased sensitivity, however, is obtained because of the increased area inside of the coil provided by the two cores side by side.

Abstract: An elongate copper coil with an open center area has a bow-tie shaped non-magnetic metal core disposed adjacent the center of the coil and insulated from the coil. The coil is adapted to be connected to a high frequency alternating current generator for producing a magnetic field in the area surrounding the coil and core for induction heating metal articles such as can ends which are moved continuously past the apparatus. The core changes the pattern of maximum flux density of the magnetic field produced by the coil to facilitate controlled transfer of heat into and out of the can ends.

Abstract: The inductance of a coil wound on one end of an elongated rectangular core with an elongated central window is caused to vary by the displacement of a conducting plate or ring arrangement lengthwise of the core. The other end of the core may also be wound with a coil to produce a differential type of transducer. The elongated core may be bent around into a circle in order to provide a transducer for rotational displacement. Additional ferromagnetic bodies in fixed relation to the core or to the short-circuiting rings can be used to modify the translation characteristic.