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5144232 Testing device for an electric generator  
An RPM and voltage indicator is used to check the operating speed and voltage output of a generator set. The device is used to verify the proper operation of a generator set or any auxiliary power...
5134378 System and method for detecting faults in generator bearing pedestals and seal insulation  
Both a system and method is provided for detecting faults in the insulating interface disposed between the shaft of a generator, and the bearings and seals that rotatably support it that generally...
5126658 Generator rotor winding ground detection  
A device for detecting a ground fault in a winding mounted to rotate with the rotor of a machine, in which an electric potential is present across the winding during machine operation, the rotor is...
5126678 A.C. Generator fault detector  
Faults in the operation of a multi-phase A.C. generator are detected by monitoring the phase difference between two line-to-line voltage of the generator and comparing this phase difference with a...
5107209 Power supply testing system for non-utility power generators  
A power supply testing system for a non-utility power generator, etc. a plurality of tank units to be powered, which are provided depending upon the number of phases of a multi-phase AC power...
5107218 Method of operation of air cleaner used in motor vehicle  
Method of operation of an air cleaner used in a motor vehicle, comprises the steps of: intermittently turning off a blower motor of the air cleaner at a given interval; detecting ripple components...
5087909 Method and apparatus for radio frequency signal detection  
A method and apparatus which indicates an actual arc occurrence only if a voltage or current of a generator neutral lead exceeds a specified threshold amplitude, and is followed by a second RF...
5055775 Transmission device  
An apparatus for tranmitting signals that can be broken down into at least one AC voltage component between a rotor and a stator from a sender unit to a receiver unit, with the help of annular...
5051682 System for detecting load on generator  
A peak hold circuit and a sample-and-hold circuit are provided for accurately and immediately detecting variations in a load connected to a generator. The peak hold circuit holds a peak voltage of...
5049815 Spectral analysis of induction motor current to detect rotor faults with reduced false alarms  
Pursuant to detecting rotor faults in an induction motor by analysis of a frequency spectrum of the current drawn by the motor under test, wherein success of the fault analysis requires an accurate...
5030917 Transient rotor fault detection in induction and synchronous motors  
To detect broken bars in the rotor of induction and synchronous motors, the current drawn by the motor during the transient startup period as the motor runs up to steady state speed is analyzed to...
5019760 Thermal life indicator  
A method for continuously determining the consumed insulation life of an electrical winding in a rotating machine is described incorporating the steps of selecting constants based on the class of...
5003252 Apparatus and method for measuring power factor and torque on the output of variable frequency drives  
An apparatus and method for sensing power factor and torque on the output of a variable frequency machine is disclosed. Initially, power is sensed in each phase of the three-phase machine by...
4996477 Apparatus and method for testing electrically controlled motor  
An on-site test unit is for an electric motor having an electronic timer having motor control contacts and a parallel capacitor completing a power connection with the opposite power connection...
4978909 Demodulation circuit for AC motor current spectral analysis  
A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in...
4973902 Fault detector for aircraft variable speed, constant frequency power supply  
A variable speed, constant frequency aircraft power system uses current sensing diodes to rectify the power generator output. The current flow through pairs of diodes is compared to generate phase...
4967123 Gyro control and monitor circuit  
An energizing and test circuit for a gyroscope spin motor which in addition o having a set of energizing coils, also includes a reference coil which generates a sinusoidal voltage whose frequency...
4965513 Motor current signature analysis method for diagnosing motor operated devices  
A motor current noise signature analysis method and apparatus for remotely monitoring the operating characteristics of an electric motor-operated device such as a motor-operated valve. Frequency...
4961157 Method and apparatus for electrostatic discharge testing of machines which repetitively execute a stored program with a plurality of program steps  
The present invention employs random electrostatic discharges to stress test electrical machinery, particularly digital computer systems running repetitive diagnostic programs. There is provided an...
4940933 Fiber optic arc monitor  
Apparatus 50 for the detection and location of arcing within an enclosed electrical device, such as an electric generator 20. Fiber optic cables 53 are strategically mounted within the generator 20...
4922172 Motor test apparatus, system and method  
An electric motor is tested by sensing the phase of an alternating current waveform to be applied to the motor, and applying the waveform to the motor in response to the phase of the waveform...
4922195 Extraneous frequency detector  
An extraneous frequency detector especially suited for analyzing the three-phase output of a variable speed constant frequency (VSCF) generator generates in a sample-and-hold circuit amplitude...
4914386 Method and apparatus for providing thermal protection for large motors based on accurate calculations of slip dependent rotor resistance  
A microprocessorized thermal protection system and accompanying method measures input voltage and current of an induction motor and derives therefrom continuously updated estimates of the slip...
4910457 Water resistance load system  
The water resistance load system which comprises a water resistor, which includes a cylindrical base electrode with a bottom for storing a predetermined quantity of water while water is circulated...
4890058 Arrangement for measuring the slip of electric induction motors  
An arrangement for measuring the slip of electric induction motors determines the relative measure of the difference between rotary field speed and rotor speed of induction motors by utilizing the...
4888996 DC motor operated valve remote monitoring system  
A method and apparatus for remotely monitoring the condition of a DC motor operated valve and/or valve operator by monitoring at a remote location, such as the Motor Control Center ("MCC"), the...
4884023 Method and apparatus for determining the rotor resistance of a rotating-field machine  
In order to determine the rotor resistance of a rotating field machine, a current is impressed in the stator via a field-oriented control, which current has a harmonic component above the nominal...
4878006 Multi-voltage motor and timer clock  
A motor having a capacitor in series with its coil permits the motor to operate at a higher voltage or range of voltages over its design voltage. A method determines the correct value of a...
4864242 Automatic field winding ground detector and locator  
A system for detecting and locating a ground fault (34) in the field winding (2) of a machine, in which a DC potential is present across the winding (2) during machine operation and the winding (2)...
4860231 Calibration technique for variable speed motors  
A variable speed motor is regulated responsive to the load torque acting on the blower wheel. The load torque acting on the blower wheel is determined by means of a coast down procedure in which...
4851766 Fault diagnosis system for rotor winding of rotary electric machine  
A fault diagnosis system for a rotor winding of rotary electric machines is disclosed, in which the rotor winding of rotary field type is excited in DC fashion by an excitation circuit, on which an...
4849690 Detection of transposition group short circuits in machine windings  
A method for nondestructively electronically detecting a short circuit in a conductor system which is composed of two parallel inductor groups connected together to form a selected current path...
4839585 Magnetic field sensor coil for being fitted around a motor shaft  
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...
4829234 Method and apparatus for measuring the resistance of the winding of a converter-fed single- or three phase machine during operation  
A method and apparatus for measuring the resistance of a winding of a converter-fed single- or three-phase machine during operation by means of a d-c measuring current. The firing instant of at...
4817045 Monitored control arrangement  
In an apparatus whose output power is monitored and controlled to avoid safety-endangering effects, such as medical equipment, a monitored control arrangement is provided which includes (1) a...
4814699 Method for partial discharge detection and breaking spark measuring in dynamo-electric high-voltage machines, and an apparatus for performing the method  
A method for partial discharge detection and breaking spark measurement in a dynamo-electric high-voltage machine, especially for monitoring insulation status during operation of a stator winding...
4813115 Method for testing and repairing synchronous motors  
An apparatus for testing a synchronizing control circuit for any assembly relying upon detecting the relative closeness of one voltage of varying frequency to another voltage of different varying...
4814700 Field current measurement device  
A rotating machine including a generator having a rotor provided with a field winding, an exciter having an armature, a rotatable steel shaft connected to the generator rotor and the exciter...
4810955 Measuring apparatus for determining the countervoltage of electric motors  
For controlling d-c motors which are supplied with an armature current obtained by phase gating, the bucking voltage induced in the motor is particularly well suited. This voltage is calculated...
4808932 Rotor fault and location detector for induction motors  
A method and apparatus for detecting rotor faults in an induction motor. Such induction motors have a stator and a rotor comprising a multiplicity of rotor bars. The flux around the rotor bars is...
4804910 Traction load meter system  
A traction load meter system for displaying information concerning the amount of current energizing electric motors which drive a locomotive. These motors have power and braking modes and have a...
4800334 Method of analyzing the voltage induced in an exciter coil of a stepping motor  
A method of analyzing the voltage induced in an exciter coil of a stepping motor. After energization the exciter coil is loaded by a low impedance so that the induction voltage can produce a...
4789834 Method and apparatus for testing of induction motor overload protection device  
A method and apparatus for testing the operability of an overload protection device for an induction motor, rapidly and without the need to mechanically load the motor output shaft. A rectifier...
4788497 Apparatus for measuring motor rotation position and speed  
An apparatus for detecting the speed and position of a rotating shaft of an electrical motor. A commutator is provided having three or more poles. First and second brushes are provided in sliding...
4786866 Method and apparatus for power steering  
The operating condition of a power steering device for use in a motor car of the type including a steering mechanism driven by a electric actuator is confirmed by supplying test current to the...
4779051 Coupling unit for the operative monitoring of the high-voltage wingings and the connected output leads in electric high-voltage machines and apparatus, by means of partial discharge determination and breakdown spark measurement  
Coupling unit for the operational monitoring of the high-voltage winding (SW) and the connected electric output lines in electric high-voltage machines and apparatus, particularly of three-phase...
4777446 Machine for the automatic testing of electric motor rotors  
A machine for the automatic testing of electric motor rotors comprises a system for checking various characteristics of rotors arriving from a line of production thereof, in which system there are...
4775828 Power level indicator for an electric generator  
A power level indicator is described for use with an electric generator for indicating to the operator the percentage of the total power available from the generator which is being consumed by a load.
4766387 Motor winding insulation resistance monitoring system  
A motor winding insulation resistance monitoring system for measuring the insulation resistance of a winding of a polyphase motor while the motor is operating including a motor winding insulation...
4763058 Method and apparatus for determining the flux angle of rotating field machine or for position-oriented operation of the machine  
For establishing the field direction without mechanical pickup upon startup of a rotating field machine, e.g., in permanent excitation, a high-frequency component (iz*) is impressed on the stator...