U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Icon_funbox Quotables


Ken Olsen, chairman and founder of Digital Equipment Corporation ; 1977

Newsletter  PatentStorm News

Make the Most of Our Site

See this month's Top Inventors and Most Cited Patents.


Registered users: Manage your profile.


Class 324/207.18 - Differential type (e.g., LVDT)

Subclass of Class 324 - Electricity: measuring and testing
Definition: Subject matter wherein (1) a sensor measures two separate
No. of patents: 235
Last issue date: 09/24/2013

NumberTitleIssue Date
8542008Displacement sensor
A displacement sensor includes a primary coil (2), secondary coils (4a, 4b), and a movable magnetic core (6) movable with displacement of an object to be measured to cause voltages generated in the secondary coils (4
8502525Integrated micro actuator and IVDT for high precision position measurements
A single housing with a non-ferromagnetic piezo-driven flexure has primary and secondary coil forms of different diameters, one coaxially inside the other, integrated in the flexure. The cylinders defining the planes of the primary and secondaries do not spatially o...
8269485Linear variable differential transformer with digital electronics
Techniques for coupling with devices that convert displacements into differential voltages and improve the sensitivity of such devices. The disclosed system improves the accuracy and resolution of a transducers such as an LVDT by converting certain parts of the circ...
8222892Sensor for simultaneous position and gap measurement
An apparatus including a controller, a transport in communication with the controller having a movable portion and a transport path and a multi-dimensional position measurement device in communication with the controller, the multi-dimensional position measurement d...
8022691Microminiature gauging displacement sensor
A device for providing displacement information includes a housing holding a displacement sensor. The displacement sensor includes a coil and a captive core. An electrical measurement of the coil provides information about displacement of the core. The coil has an a...
7936166Quarter cycle waveform detector
A method for extracting peak information from an amplitude varying sinusoidal waveform output from a sensor is provided. The method includes gating a counter with a keying signal having a keying-signal period generated by a sinusoidal waveform associated with the am...
7893687LVDT acquisition device with dual demodulation subsystem
The invention relates to position sensors of the linearly variable induction difference type. When cost constraints prevent the use of transformers with guaranteed phase-shift tolerance to achieve an accuracy objective, it is advantageous to provide an independent d...
7764063Brushless resolver and method of constructing the same
A brushless resolver (10) comprises exciting signal transmitting means for transmitting a resolver exciting signal from the stator (3) side to the rotor (4) side in a noncontact way and a resolver part (7) for modulating the resolver exci...
7459904Precision position sensor using a nonmagnetic coil form
A position sensor has a moving coil part that is formed from a first coil form formed of a non ferromagnetic material, and a second coil that also has its form made of non-ferromagnetic material. The coil forms can be formed of non ferromagnetic adhesive. One of the...
7436173Measurement configuration
A movement distance sensor operates as a differential transformer with a primary coil, at least two secondary coils. A circuit configuration is connected to the secondary coils in order to determine a movement distance. The circuit configuration includes a multiplex...
7391202Linear variable differential transformer (LVDT) system using an inductance of an LVDT primary as a micro-power excitation carrier frequency to lower a drive power
A linear variable differential transformer (LVDT) system is disclosed. The system has an LVDT. A signal conditioner circuit is coupled to the LVDT. The signal conditioner circuit uses an inductance of the LVDT primary as a micro-power excitation carrier frequency to...
7372254Linear force detecting element formed without ferromagnetic materials which produces a resolution in a range of microns or less
A force detecting element is used to move a moving coil that is formed without ferromagnetic materials and is driven using a stationary coil that is formed without ferromagnetic materials, thereby producing an output signal which is more linear than the previous tec...
7367132Contact-type displacement measuring apparatus
A contact-type displacement measuring apparatus includes a first movable body that reciprocates in a first linear direction; a driving unit that drives the first movable body; a second movable body that reciprocates in a second linear direction parallel to the first...
7322744Temperature measurement device
A temperature measuring device includes a temperature-responsive element that mechanically moves a first inductive assembly component relative to a second inductive assembly component in response to temperature changes. The movement of the first inductive assembly c...
7321229Inductive position sensors with secondary windings with increased or decreased number of turns
A position sensor comprising a primary winding (26) for generating a magnetic flux, a first secondary winding (24.1) the number of turns of which increases in one direction, a second secondary winding (24.2) the number of turns of which increase...
7317371Linear variable differential transformer with complimentary step-winding secondary coils
A linear variable differential transformer comprising a coil form; a first primary coil; an optional second primary coil; a first secondary coil; and a second secondary coil; wherein the windings of the secondary coils create complimentary and preferably uniform ste...
7281432Displacement sensor with an excitation coil and a detection coil
To be able to detect a displacement amount of a moving object by a resolution of from micrometer to nanometer by a simple structure. An excitation coil 23 and a detection coil 25 are arranged to align and a magnetic body probe 27 in a con...
7282907Antifriction bearing unit having a sensor and a resolver
An outer ring is provided with the stator of a resolver, and a ring member with the rotor of the resolver. The stator comprises an annular core and a winding provided around the core. The ring member is provided at a position opposed to the stator with an eccentric ...
7271582Linear variable differential transformers for high precision position measurements
A linear variable transformer (LVDT) for use in a transducer. The LVDT has a non-ferromagnetic core which may eliminate Barkhausen noise and thereby improve the sensitivity of the resulting measurements. In one aspect, this system may be used in an atomic force micr...
7263453Shaft feedback sensor error detection
Methods and apparatus for detecting a sensor angle error in a system in which a measured quantity is determined on the basis of a phase of a signal. A signal derived from the measurement of multiple sensors is ascribed to a vector in a two-dimensional space, and a n...
7262592Linear variable differential transformers for high precision position measurements
A linear variable differential transformer (LVDT) is disclosed that has first and second coil is formed of materials that minimize the Barkhausen noise, and hence which produces outputs that are substantially independent of any Barkhausen noise. In an embodiment, th...
7257506Position detecting system and method
7242182Position sensor and corresponding method for detecting the position of a rotating element
A low-wear sensor with little structural outlay to detect a combined linear and rotational movement, such as in a print roller (10). In one embodiment, a PLCD (Permanent Magnetic Linear contactless Displacement) sensor includes a magnet (5) which can b...
7235966Resolver unit and resolver using same
A resolver unit having a structure in which the axial length is shortened to prevent the magnetic coupling characteristic between the rotary and stationary sides from being impaired, a winding generates more magnetic fluxes, and multiplexing is easily conducted, and...
7233140Position sensing assembly with sychronizing capability
A linear variable transformer, or LVDT, for use with the transducer, which has a non-ferromagnetic core that can eliminate Barkhausen noise. By eliminating the Barkhausen noise, the sensitivity of the resulting measurements can be improved. The LVDT is formed of mul...
7215129Multi tip clearance measurement system and method of operation
A multi tip clearance measurement system is provided. The clearance measurement system includes a sensor disposed on a first object, wherein the sensor comprises a plurality of probe tips configured to generate signals representative of a sensed parameter correspond...
7215116Variable reluctance type angle detector
Provided is a variable reluctance type angle detector whose exciting winding resistance can be reduced to increase an exciting current without an increase in exciting power source voltage, thereby reducing an influence caused by a noise. The variable reluctance type...
7191754Position sensor apparatus and method
A control system having a housing with a bore formed within the housing. A valve member is associated with the bore for controlling the passage of a fluid medium through the bore. An induction sensor is aligned with the valve and facilitates determining the valve po...
7182063Assembly with non-contacting position sensor
An electronic throttle control system is described. The system includes a non-contacting sensor stator integrated into an electronic throttle body and is aligned to the sensor rotor attached to the shaft to properly set sensor air gap by assembly aids or by close fi...
7173558Charge comparator with low input offset
A Direct Current (DC) charge comparator that provides low input offset by feeding complimentary plus and minus charge inputs to a single amplification path via an alternate input path switch. Multiple sample and hold circuits at the output of the amplification path ...
7170208Connector with flux concentrator for electric motor
A connector for an electric motor including a magnetic ring which is the seat of a magnetic field tied to operating parameters of the motor. A magnetic flux conduction member forms a flux concentrator interposed, when a connector is fixed on the motor, between the m...
7171342Method for determining magnetization and the field radiated by a ferromagnetic plate
The invention concerns the field of devices and appliances for measuring the intensity and the direction of the magnetic field emitted by a plate or a structure, such as for example a ship's hull and it particularly concerns a method for determining the magnetisatio...
7157906Double variable reluctance resolver for a multiple speed resolver system
A double variable reluctance resolver in which a redundancy is given to a variable reluctance resolver to improve reliability. The double variable reluctance resolver also functions as a multiple speed resolver system. ...
7157913Re-configurable induction coil for metal detection
A device in which the receiver coil of a pulse inductive metal detector is capable of switching between a differential configuration (i.e., gradiometer configuration) to a non-differential or summing configuration under control of the operator or computer. ...
7154265Eddy current probe and inspection method
An eddy current (EC) probe for inspecting a component is provided. The EC probe includes a tangential drive coil configured to generate a probing field for inducing eddy currents in the component, where a portion of the eddy currents are aligned parallel to an edge ...
7148817Device for positional and/or length determination
A device for positional and/or length determination comprising a carrier unit with an absolute magnetic length coding and a measuring unit that co-operates with the carrier measuring unit and can be displaced in relation to the latter. The measuring unit has a magne...
7138794Detection of faults in linear and rotary voltage transducers
Systems and methods for detecting faults in RVDTs and LVDTs are described. In an exemplary embodiment, a sum of secondary voltages V1 and V2 from a transducer is obtained by adding the secondary voltages together, i.e.; V1+V2. This sum of secondary voltages theoreti...
7135855Simplified inductive position sensor and circuit configuration
Inductive position sensors and circuit configurations are disclosed for the measurement of linear, rotary, or curved position along a motion axis. The simplified sensor structures combine one or two parts of a movable core element with a simple planar substrate havi...
7132825Detection device
A device for detecting the displacement of an object comprising a ferromagnetic material, comprises a magnetic circuit generator provided with first and a second cores made of ferromagnetic material and an excitation coil and a measurement coil. The magnetic circuit...
Sign InRegister
forgot password?