|
Match
|
Document |
Document Title |
|
|
5523701 |
Method and apparatus for monitoring machine performance
Machine operating conditions can be monitored by analyzing, in either the time or frequency domain, the spectral components of the motor current. Changes in the electric background noise, induced...
|
|
|
5519337 |
Motor monitoring method and apparatus using high frequency current components
A motor current analysis method and apparatus for monitoring electrical-motor-driven devices. The method and apparatus utilize high frequency portions of the motor current spectra to evaluate the...
|
|
|
5514978 |
Stator turn fault detector for AC motor
Motor current and voltage waveforms are measured and converted to digitized current and voltage waveforms. A weighted discrete fourier transform is applied to the digitized current and voltage...
|
|
|
5514967 |
Automatic insulation test equipment for testing high voltage electrical equipment at the rated voltage level
Insulation test equipment for testing high voltage electrical equipment at rated voltage levels up to above 5 kV. A multistage rectifier-capacitor voltage multiplier ladder is used to boost the...
|
|
|
5514977 |
Pulse detection and conditioning circuit
A pulse detection and conditioning circuit senses and conditions commutation pulses produced by a DC permanent magnet motor to determine motor position. The pulses are sensed using a resistor...
|
|
|
5512843 |
Monitoring method and apparatus using high-frequency carrier
A method and apparatus for monitoring an electrical-motor-driven device by injecting a high frequency carrier signal onto the power line current. The method is accomplished by injecting a high...
|
|
|
5510726 |
Armature tester
A method and apparatus are provided for determining angular alignment between a lamination stack, a commutator, and coil windings of an armature for an electric motor. The apparatus has a body with...
|
|
|
5508620 |
Method and device for determining ground faults on the conductors of an electrical machine
A method is specified for detecting ground faults on the conductors of electrical machines, in which method the fault resistance (Rf) is directly calculated in a numerical evaluation unit (7) from...
|
|
|
5508633 |
Method of and apparatus for testing and adjusting d.c. rotary machines
Apparatus may be inserted in the casing of a d.c. motor or a d.c. generator for measuring not only the magnetic fields prevailing in the machine but developing other useful information. The...
|
|
|
5477163 |
Turn fault detection
A method for detecting turn faults in an induction motor comprises measuring at least two motor phase currents, at least two motor phase voltages, and the negative sequence impedance. Motor torque...
|
|
|
5477162 |
Method for determining the short-circuit inductance of an asynchronous machine
A method of determining a short-circuit inductance in an asynchronous machine even during operation of the machine includes the steps of causing a step change in the stator voltage (u s );...
|
|
|
5475299 |
Method for remotely determining operability of motor operated valves
A method is disclosed for determining operability of a motor operated valve combination including a valve having a valve stem, a valve disc, a valve seat, and a motor operator having a motor drive...
|
|
|
5475312 |
Method and device for distinguishing between partial discharge and electrical noise
A method and device for distinguishing between partial discharge and electrical noise in high voltage conductors such as in motor and generator stators, power cables, gas insulated switchgear and...
|
|
|
5471135 |
Tester and method for testing a rectifier-regulator
A tester and method for testing a rectifier-regulator. A ramping voltage generator generates a ramping input voltage during each of a multiplicity of ramping cycles in response to ramping voltage...
|
|
|
5467025 |
Sensorless rotor position measurement in electric machines
A sensorless rotor position measurement system comprises a digital processor (6) which receives signals from current and flux sensors (7, 8) of the current and flux associated with a phase winding...
|
|
|
5461329 |
Method and apparatus for generating motor current spectra to enhance motor system fault detection
A method and circuitry for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are...
|
|
|
5457402 |
Armature resistance measuring apparatus and method
A method and apparatus for determining the resistance of the coils and commutator connections in an armature of an electric motor wherein a current is generated between a first commutator segment...
|
|
|
5446389 |
Portable test set for testing operability of a locomotive
A portable test kit for testing electrical and mechanical operation of a locomotive includes one multi-pin connector for connecting to an MU connector on a locomotive. The multi-pin connector is...
|
|
|
5432436 |
Method for remotely approximating the stem thurst of motor operated valves
A method is disclosed for approximating the stem thrust during the operation of a motor operated valve combination including a valve having a valve stem, a valve disk, a valve seat, and a motor...
|
|
|
5420523 |
Apparatus and method for measuring performance parameters of electric motors
There is disclosed an apparatus and method for determining locked rotor test data for three-phase alternating current motor without mechanically coupling the rotor to any instrumentality. The...
|
|
|
5416430 |
Apparatus and method for identification and location of internal arcing in dynamoelectric machines
The present invention monitors RF emissions within a turbine generator. A coupling device provides a connection between preexisting thermal sensor leads and an RF monitor. Preexisting thermal...
|
|
|
5404108 |
Method and apparatus for testing electric motor rotors
A testing apparatus for rotors of electric motors comprising a test fixture including a fixture shaft on which a rotor is temporarily attached to a known inertial load. A stator creates a rotating...
|
|
|
5402080 |
Method of measuring unsaturated inductances of an equivalent circuit of a synchronous machine
Unsaturated inductances of an equivalent circuit of a synchronous machine are measured from the following steps: An armature resistance of a synchronous machine is measured. A time constant of an...
|
|
|
5394102 |
Non-repeatable run-out measuring instrument using encoder signals based upon the back EMF of a motor as trigger signals
The specification discloses an NRR (Non-Repeatable Run-out) measuring instrument for measuring the NRR of the rotating object motor to be measured without installation of a special attachment such...
|
|
|
5371458 |
Method for determining the stator flux of an asynchronous machine
The invention relates to a method for determining the stator flux of an asynchronous machine when a stator current (i 2 ) and stator voltage (u s ) of the asynchronous machine are measured and a...
|
|
|
5363039 |
Auto self test of AC motor system
Apparatus and method for auto-self testing of a power converter and motor system wherein the power converter has three parallel legs, each including two series connected gate-turn-off thyristors...
|
|
|
5341095 |
Dynamoelectric machine stator test device
A stator testing device for a dynamoelectric machine formed from a plurality of laminations defining a plurality of substantially parallel stator teeth each extending over a preselected length of...
|
|
|
5336993 |
Assembly for testing rectifiers and regulators of automotive alternators
A test assembly for testing regulators and rectifiers. The assembly includes two main components: a modified alternator and a test board. The test board has a regulator test station, which is...
|
|
|
5319304 |
Device for monitoring load
A load measuring device includes a sensor for detecting power consumption surges by detecting a zero voltage point in the alternating voltage of an electrical apparatus, detecting the zero current...
|
|
|
5311121 |
Apparatus for measuring the electrical time constant of the quadrature-axis damper of a synchronous machine
An apparatus for measuring the electrical time constant of the quadrature-axis damper of a synchronous machine is designed such that a voltage from a d.c. power source is applied by switching to...
|
|
|
5291128 |
Motor testing apparatus utilizing inertial loading
An improved testing apparatus for an electric motor in which the motor windings are energized in a manner to produce low frequency oscillatory rotation of the motor armature. Under such conditions,...
|
|
|
5281908 |
Loading device assembly
A transportable loading device assembly includes a low-voltage small-capacity variable loading device having a load change-over element which enables the load to be applied to be incrementally...
|
|
|
5270640 |
Method for incipient failure detection in electric machines
An improved method for detecting an incipient failure in a multiphase electric motor includes the following steps: periodically measuring or continuously monitoring voltage and current values at...
|
|
|
5266893 |
Method and apparatus for testing VCR servos
The capstan and drum servo systems of a VCR are tested by processing the capstan reference signal and the drum reference signal in a microprocessor and displaying information which is useful in...
|
|
|
5262717 |
Method and apparatus for measuring electric motor efficiency and loading
A method for determining the efficiency and loading of an electric motor comprises affixing a strain gauge to the drive shaft, calibrating the strain gauge, measuring the input power of the motor,...
|
|
|
5252927 |
Device for monitoring corona discharge in a dynamoelectric machine with detection probe movable in longitudinal and circumferential direction
In the device for detecting partial discharges in winding elements of an electrical machine, the winding element to be investigated is sampled over its length, with high voltage applied, by means...
|
|
|
5252915 |
Method and apparatus for detecting stator faults in rotary dynamoelectric machines
In order to determine the occurrence of a stator fault in an induction motor during operation of the motor, the axial leakage flux is monitored during operation of the motor. The occurrence of a...
|
|
|
5252926 |
Apparatus and method for distinguishing between faults due to alternator failure and interruption of stator phase signals in automotive battery charging systems
An automotive charging circuit fault detection circuit includes a pseudo stator-phase signal generator and a stator-phase existence circuit for determining if a stator-phase signal is below a...
|
|
|
5239874 |
Method of monitoring the condition of a motor operated valve system
A method of evaluating degradations throughout a MOV (i.e. motor operated valve) by establishing specific interrelationships between a power related parameter from the MOV motor (being, for an AC...
|
|
|
5231348 |
Method and apparatus for testing dynamoelectric machine rotors
A method and apparatus for testing dynamoelectric machine rotors, particularly squirrel cage rotors for induction motors, to obtain resistance, reactance, and effective skew values to permit...
|
|
|
5202620 |
Apparatus for measuring the time constant of the direct-axis damper of a synchronous machine
An apparatus for measuring the time constant of the direct-axis damper of a synchronous machine is designed such that a voltage from a d.c. power source is applied by switching to armature windings...
|
|
|
5187434 |
Apparatus for detecting machining conditions of a workpiece
An apparatus for detecting machining conditions in a machine tool has a magnetic bearing for magnetically supporting a work spindle or a tool spindle. An exciting current detector is provided for...
|
|
|
5187433 |
Devices for measuring braking torques generated by electromagnetic retarders, and devices for adjusting such torques
A measuring device for measuring the braking torques generated by a vehicle-mounted electromagnetic retarder having a fixed secondary magnetic circuit or "stator". The device includes a sensor for...
|
|
|
5172048 |
Device for measuring the number of revolutions of the shaft of a permanent magnet electric motor
The device measures the number of revolutions completed by the shaft of a permanent magnet electric motor in a period of time during which it is set in motion by the effect of its connection to a...
|
|
|
5170116 |
Method and device for magnetic flux estimation in an asynchronous electric motor for control thereof by magnetic flux regulation
A method and device are provided for estimating the magnetic induction flux of an asynchronous electric motor, notably for enabling said motor to be controlled by magnetic induction flux...
|
|
|
5164662 |
Detection of radio frequency emissions
A method and system for detecting radio frequency emissions in an electrical machine, by: sensing the radio frequency emissions and deriving a light signal modulated by the radio frequency...
|
|
|
5163172 |
Procedure and apparatus for the measurement of the currents in a frequency converter
A procedure and apparatus for the measurement of the currents in a frequency converter, provides that the phase currents of the frequency converter are measured by storing, in memory, signals...
|
|
|
5162727 |
Method and apparatus of determining the stator flux estimate of an electric machine
The invention relates to a method of determining the estimate of the stator flux of an electric machine, comprising the determination of a stator flux estimate (Φ sest ) of the electric machine as...
|
|
|
5153506 |
Apparatus for measuring a winding temperature of electric machines
An apparatus for measuring the winding temperature of electric machines uses an a.c. reference voltage source generating an a.c. reference voltage with a predetermined, non-line frequency,...
|
|
|
5151647 |
Enhanced charging system diagnostic method
A method for detecting full or partial inoperability of a vehicular alternator battery charging system monitors the vehicle's battery voltage and compares it against a controlled reference voltage....
|