Class 318/657 - Linear differential transformer

Subclass of Class 318 - Electricity: motive power systems
Definition: Subject matter in which the differential transformer is
No. of patents: 38
Last issue date: 10/31/2006

Browse patents
Browse applications

Number	Title	Issue Date
7129665	Control apparatus for feed driving system A control apparatus for a machine that can be operated at high precision in a stable control state is provided by driving a movable body with control parameters suited to the mechanical state. A control parameter calculation circuit is provided to obtain control par...	10/31/2006
7053603	Circuit arrangement with a linear variable differential transformer (LVDT) as a displacement sensor or force sensor In a circuit arrangement having a linear variable differential transformer as a displacement sensor or force sensor, having a selection circuit which is connected to the primary coil of the transformer and which provides an output current for triggering the primary ...	05/30/2006
6930831	Vari-focal polar alignment scope A vari-focal polar alignment scope includes an objective optical system, a relay optical system, and an eyepiece optical system, in that order from the object side. The relay optical system includes an erecting vari-focal viewing optical system, including a positive...	08/16/2005
6864808	System and method for processing a signal Analog circuitry is disclosed for conditioning a signal from linear and rotary variable differential transformers having a primary winding, a pair of secondary windings and a movable core. The circuitry includes a unique closed loop negative feedback mechanism which...	03/08/2005
6489760	High sensitivity displacement measuring device using linear variable differential transformer The present invention is intended to provide a ultra-precision high sensitivity displacement measuring device which has such a high resolution as to be able to make submicron measurement. According to the invention, there is provided a displacement measuring ...	12/03/2002
5777468	Variable differential transformer system and method providing improved temperature stability and sensor fault detection apparatus A variable differential transformer system (10), both linear and rotary (L/RVDT) includes a primary coil (12) drive by a primary drive (20) having a triangle wave generator whose frequency is set by an external frequency control (Rosc and C	07/07/1998
5422555	Apparatus and method for establishing a reference signal with an LVDT A system for creating a position reference signal includes a linear variable differential transformer (LVDT), a magnetically permeable core capable of entering and existing the chamber of the LVDT, a positioning means for moving the core in forward and ba...	06/06/1995
5327030	Decoder and monolithic integrated circuit incorporating same A monolithic interface circuit for use with a linear variable differential transformer (LVDT) position transducer. The interface circuit includes a drive circuit for providing an excitation signal of selectable frequency and amplitude to the LVDT primary ...	07/05/1994
5235274	Pulsed excitation position sensor system using linear variable differential transducers with multiplexing A device for measuring the position of an element utilizing a linear variable differential transducer. The primary of the transducer is excited by using a single pulse, causing an induced pulse to be created at the secondary coil. The induced pulse is com...	08/10/1993
5204603	Open circuit detection for a pulsed resolver position sensing system An auxiliary resolver position tracking (RPT) system for an industrial robot includes a resolver excitation and monitoring system which is powered by an uninterruptable power supply which includes a battery. The RPT system generates trapezoidal excitation...	04/20/1993
5196776	Waveform generator for a resolver A waveform generator for a resolver transducer or the like is described. Such generator forms two 3-level waveforms which approximate sinusoidal waveforms for the excitation and/or output detection of such a resolver. Each of the sinusoidal waveforms is f...	03/23/1993
5121042	Electro-hydraulic servo mechanism An electro-hydraulic servo mechanism comprising: a hydraulic actuator formed with a pair of hydraulic chambers and having an output member which is displaced by a differential pressure between the hydraulic chambers, the output member being connected with...	06/09/1992
5087866	Temperature compensating circuit for LVDT and control system A linear variable displacement transducer (LVDT) has a core connected to an actuator such as a torque motor. The outputs of the LVDT are demodulated and subtracted to provide a displacement signal which is compared with a desired displacement to provide c...	02/11/1992
4920305	Auto calibrating electro hydraulic servo driver An electro-hydraulic positioning system which has automatic calibration capabilities is disclosed. The system includes a microprocessor which accesses calibration parameters stored in a non-volatile memory unit. The microprocessor adjusts the position dem...	04/24/1990
4904921	Monolithic interface circuit for linear variable differential transformers A monlithic interface circuit for use with a linear variable differential transformer (LVDT) position transducer. The interface circuit includes a drive circuit for providing an excitation signal of selectable frequency and amplitude to the LVDT primary w...	02/27/1990
4847548	Signal conditioner for a linear variable differential transformer A signal conditioner for a linear variable differential transformer having a first amplifier which senses the differences in amplitude between secondary alternating current voltages in the two secondaries respectively, and a second amplifier which compare...	07/11/1989
4783626	Displacement detector with three secondary coils, one of which provides a constant bias output A displacement detector includes a movable member of a magnetic material movable as a function of the displacement of an object which is to be detected, an AC signal source, a primary coil energizable by an AC signal supplied by the AC signal source for g...	11/08/1988
4780655	Drive and position sensor for a driven part A drive and position sensor having a drive shaft for positioning a driven part and connected to a magnetic core by a reduction gear to position the core axially relative to a primary and secondary coil so that the voltage in the secondary coil is a measur...	10/25/1988
4678991	Inductive displacement transducer with unipolar output A unipolar signal indication of core position is provided in an inductive displacement transducer, such as an LVDT, as the sum magnitude of the transducer's applied primary winding voltage signal and the transducer's induced secondary winding voltages....	07/07/1987
4651130	Apparatus and method for retaining phase information for use with a multiple-coil inductive displacement sensor Phase information in a multiple-coil indictive displacement sensor is retained by summing the excitation signal with each of the secondary signals to provide augmented secondary signals which may then be converted to a digital format. A signal processor m...	03/17/1987
4628499	Linear servoactuator with integrated transformer position sensor A linear servoactuator including an integrated split-secondary differential transformer position sensor and a fluid driven linear actuator controlled by solenoid poppet valves. Signals from the position sensor transformer are digitized and linearized by a...	12/09/1986
4599560	AC excited transducer having stabilized phase sensitive demodulator circuit A signal conditioning circuit (30) using an oscillator (32) which feeds a counter (34) whose output addresses a programmable memory (42). The output of the programmable memory (42) provides a selected processed signal which is used for excitation of a tra...	07/08/1986
4514689	High resolution position sensing apparatus with linear variable differential transformers having phase-shifted energizing signals Apparatus for high resolution sensing of the position of a rapidly moving member. The apparatus includes at least two linear variable differential transformers (LVDT's) each having a magnetic core coupled to the movable member. A signal source and a phase...	04/30/1985
4467320	Measurement of a linear variable differential transformer signal by phase conversion A measurement system for converting the outputs of dissimilar transducers into digital numbers by means of a phase conversion technique. The outputs of a plurality of dissimilar transducers are generated as pairs of amplitude modulated sinusoidal signals....	08/21/1984
4450443	Position transducer for digital systems A position transducer for indicating the position of a core member of a linear variable differential transformer produces DC level output signals proportional to changes occurring in the excitation and core displacement. Pulse signals from a clock source ...	05/22/1984
4447770	Precision drive system A precision drive system including a base plate; track means and an air bearing means movable relative to one another, one of the means being fixed to the base plate and the other being movable for carrying an object to be moved relative to the base plate...	05/08/1984
4328449	Device for controlling the speed of movement of a mobile member A device for controlling the speed of movement of a mobile member relative to a fixed support member, said mobile member receiving its motion from first drive means is described. The main feature of said drive is that it comprises a speed transducer opera...	05/04/1982
4323884	Digital-analog interface for insertion between a digital control signal transmitter and a controlled moving element This invention relates to a digital-analog interface for insertion between the control circuit of a moving element and a transmitter of digital control signals. This interface comprises an inductive detector of the actual position of the moving element. T...	04/06/1982
4251760	Gauging and tool control system for production of identical parts A system for duplicating a master part includes a gauge for measuring changes in the dimension therein of a master part to be duplicated and for providing control signals representative of changes from a predetermined dimension. The control signals are ap...	02/17/1981
4220430	Positioning device for positioning a movable part of a machine tool relative to a fixed part A positioning device for positioning a part, such as, a movable part of a machine tool, relative to a fixed part of the machine tool, comprises, a transmitter adapted to be secured to one of said fixed and movable parts and having spaced apart first and s...	09/02/1980
4205217	Automatic weld line copying apparatus An automatic weld line copying apparatus has a non-contact type sensor including a core wound with an exciting primary winding which in turn is wound with a secondary winding a plurality of secondary coils differentially. The sensor is compact and able to...	05/27/1980
4163929	Handle apparatus for a power-assist device A handle apparatus is for use with a device which has a movable component and a variable speed motor system which is responsive to an error signal for driving the movable component to desired positions corresponding to the error signal. The handle apparat...	08/07/1979
4140998	High accuracy position indicator A position indicator is disclosed which includes the combination of a linear voltage differential transformer (LVDT) and accuracy assurance circuitry. The LVDT includes a movable core connected to a mechanism whose position is to be indicated. The accurac...	02/20/1979
4109189	Phase-sensitive transducer apparatus with improved signal offset means A phase-sensitive transducer apparatus comprises first and second relatively movable members, the first relatively movable member having a plurality of windings and the second relatively movable member having a winding. Means are included for applying a f...	08/22/1978
4109200	Position sensing differential transformer system with means to convert the output to an absolute value A stator lamination compression mechanism simultaneously monitors the axial length of a series of laminations to be used in an electric motor. A linear variable differential transformer provides a movable coupling element connected to a sensing member mon...	08/22/1978
4059789	Phase-sensitive transducer apparatus with signal offset means A phase-sensitive transducer apparatus comprises first and second relatively movable members, the first relatively movable member having a plurality of windings and the second relatively movable member having a winding. Means are included for applying a f...	11/22/1977
4047086	Phase-sensitive transducer apparatus A phase-sensitive transducer apparatus comprises first and second relatively movable members wherein the first relatively movable member has a plurality of windings and the second relatively movable member has a winding. Means are included for applying a ...	09/06/1977
3939389	Positioning control apparatus A device for positioning a part comprises a signal generator which, upon movement of said part within the vicinity of a required position of the part, produces a signal value which passes through zero at a point when said part is in said required position...	02/17/1976

PatentStorm

Bizarre Patents

PatentStorm News

Class 318/657 - Linear differential transformer