Abstract: The present disclosure relates to a method of advanced motor control that reduces the resource demands (e.g., run-time) used to meet safety requirements by running a reduced portion of feedback control loop processes twice. In some embodiments, the method performs a plurality of processes within a feedback control loop of a motor control process configured to control operation of a motor. Performance of a first portion of the plurality of processes, which is less than the plurality of processes, is repeated within the feedback control loop. Performance of a second portion of the plurality of processes is not repeated within the feedback control loop. By repeating performance of first portion of the plurality of processes that is less than the plurality of processes, the method is able to improve performance of a motor by reducing run-time of the motor control process.

Abstract: A diagnostic apparatus that diagnoses a cutter tool or a rotating machine based on electric power supplied to the rotating machine, includes: an electric power measurement unit that measures the electric power; and a filtering unit that filters noises input from an input side and an output side of the electric power measurement unit, the electric power measurement unit including a Hall element, and applied voltage of an electric power supply line, that supplies the electric power to the rotating machine from an inverter or a servo amplifier, is input in the Hall element, wherein the electric power is calculated based on Hall voltage that is generated, when Hall current flows through the Hall element and magnetic flux is applied to a sensor surface of the Hall element, the Hall voltage being proportional to a product of the magnetic flux and the Hall current.

Abstract: An anomaly diagnosis system is provided that includes: a current-value obtaining part 111 that obtains a value of an AC current inputted to or outputted from a device to be diagnosed; a frequency analyzing part 112 that converts the current values obtained at intervals into a frequency spectrum which correlates a current intensity with a frequency; an anomaly-judging-value calculating part 113 that calculates at intervals a frequency width of the frequency spectrum at a current intensity “As” satisfying As=m×At (0<m<1), where “At” is a peak current intensity associated with an analysis frequency which is an integer multiple of a frequency of the AC current; and a judging part 114 that judges whether the frequency width is wider than that in a normal condition and, if it holds true, judges that the device is in an anomalous condition.

Abstract: Disclosed is an apparatus and method for estimating a SOC of a secondary battery containing a blended cathode material. The SOC estimating apparatus estimates a SOC of a secondary battery including a cathode having a blended cathode material containing a first cathode material and a second cathode material with different operating voltage ranges, an anode having an anode material, and a separator for separating the cathode from the anode, and the apparatus includes a sensor configured to measure a discharge inception voltage and a final discharge voltage when the secondary battery is discharged for a predetermined time, and a control unit configured to estimate SOC of the secondary battery corresponding to the measured discharge inception voltage and the measured final discharge voltage by using a predetermined relationship between the discharge inception voltage and the final discharge voltage and the SOC of the secondary battery.

Abstract: An image forming apparatus, including a storage unit wirelessly accessible from an external device, switches its operation mode related to wireless access of the image forming apparatus between an active mode in which a signal for wirelessly connecting to an external device is transmitted and a passive mode enabling access to the storage unit in response to a signal for wireless connection from an external device.

Abstract: A leakage detection breaker includes a current transformer configured to detect a leakage current, and a leakage determination unit configured to determine DC and AC leakages based on an output signal from the current transformer. The leakage detection breaker further includes a power supply cut-off unit configured to cut off a supply of DC or AC power when the current leakage determination unit determines the occurrence of the DC or AC leakage.

Abstract: A circuit arrangement for revealing light signal errors, in particular for railway safety systems, includes an electronic signal generator, which can be disconnected in a reversible manner in the event of an error, and a control part, configured for incandescent lamps, for controlling and monitoring the signal generator. The device for revealing errors includes an error differentiator between the line-related interference voltage and error of the signal generator. The reliability of the error differentiation is improved and rendered independent of capacitive intermediate energy storage devices, in that the signal generator is connected to a resistance arrangement such that the signal generator voltage is greater, in high-resistance signal generators, than an interference voltage.

Abstract: A system for detecting faults in a motor includes a drive circuit, a detection circuit, and a controller. The drive circuit is configured to apply a drive signal to a motor. The detection circuit is configured to detect a response signal generated when the drive signal is applied to the motor. The controller is configured to determine a motor fault based on a comparison of the response signal to an expected signal for the drive signal applied to the motor. The drive signal is selected to generate a rotating magnetic field in the motor with a rotation-frequency greater than a maximum mechanical-response-frequency of the motor.

Abstract: A method is provided for detection of a ground fault in a high resistance network in a voltage source power conversion circuit comprising a power converter that converts incoming AC power to DC power applied to a DC bus and an inverter that converts DC power from the DC bus to output AC power. The method includes detecting a midpoint-to-ground voltage between a low side of the DC bus and a ground potential and detecting the presence of a ground fault in a high resistance network based upon the detected midpoint-to-ground voltage.

Abstract: A device comprises a battery having a multiplicity of battery cells and a sensor system for the redundant determination of a battery current flowing through the poles of the battery. The sensor system comprises a current measuring device for detecting the battery current and providing a current measurement value. Furthermore, the device comprises a voltage measuring device for separately detecting a variation with time of the single-cell voltage of at least one battery cell and providing at least one variation with time of a voltage measurement value. Furthermore, the device comprises an evaluating unit which is configured for determining the battery current from the at least one variation with time of the voltage measurement value, providing a corresponding current value and comparing the current value with the current measurement value.

Abstract: The present invention relates to a client suitability test apparatus for a substation automating system with regard to IEC 61850 service between virtual intelligent electronic devices (IEDs) and clients for a plurality of IEDs, wherein the apparatus comprises: a suitability test process generating unit using at least one test model selected from among a plurality of predefined test models, and modeling a suitability test process to test the suitability of a client; a suitability test executing unit for calling a test process model, and executing a suitability test on a client according to the content of the test process model; a communication packet analyzing unit capturing and analyzing a communication packet on a communication response of a virtual IED and the communication request of a client according to the suitability test executing unit; and a test grading unit for grading the suitability test of the client based on test grading conditions of the test process model called by the suitability test execut

Abstract: Disclosed is a method of controlling the power input to a HVDC transmission link, which HVDC transmission link is connected to an AC power plant via a first voltage source converter and to AC grid via a second voltage source converter, which method includes using the second voltage source converter to perform voltage control of the HVDC transmission link during a no-fault mode of operation of the grid; monitoring a HVDC transmission link parameter to detect an unbalanced fault; and using the first voltage source converter to regulate the output of the AC power plant on the basis of the monitored HVDC transmission link parameter in the event of an unbalanced fault. Also described are a control module for controlling the power input to a HVDC transmission link; a voltage source converter for a power plant; and a power generation and transmission arrangement.

Abstract: A signal generator generates a combined signal that is generated only in the period where supply of a pulse signal is effected, a pulse signal whose frequency is of a higher impulse repetition frequency than the frequency of the period setting signal and whose amplitude represents a voltage value that is lower than the high voltage HVDC value. A semiconductor switch accumulates electric charge on a capacitative element by means of the high voltage HVDC from the high voltage generator when the voltage value of the combined signal is lower than the set gate voltage value and generates an impulse voltage whose peak value is the value of the high voltage HVDC, by means of the electric charge that is discharged from the capacitative element when the voltage value of the combined signal exceeds the set gate voltage value.

Abstract: With a rotating electric machine testing method for applying a test voltage to an armature winding of the rotating electric machine to thereby test insulation performance of the armature winding, in the case where a rated voltage of the armature winding of the rotating electric machine is E, and an insulation test voltage of an armature winding of a sine wave voltage drive rotating electric machine at the rated voltage E is E/?{square root over (3)} or E, a test voltage Vtest applied to an armature winding of the inverter drive rotating electric machine is set to Vtest=?·E/?{square root over (3)} or Vtest?=?·E, respectively, provided that ?(=tinv/tsin), if the insulation thicknesses of the sine wave drive rotating electric machine is tsin and of the inverter drive rotating electric machine is tinv, thereby conducting a test on any of the AC voltage-current characteristic, AC tan ?, and AC partial-discharge characteristics.

Abstract: A method of increasing a current sensing range for a vehicle or other polyphase motor system includes measuring phase currents delivered to a motor of the system. A controller calculates an absolute value of each phase current, compares each calculated absolute value to a saturation limit to determine whether only one sensor is saturated, and extrapolates a phase current value of the saturated sensor. The calculated temporary phase current is used as the extrapolated phase current value for the saturated sensor, and a control action is executed using the extrapolated phase current value only when the calculated temporary phase current value exceeds the measured value for the saturated sensor and a sign of the calculated temporary phase current value matches that of the measured value for the saturated sensor. A system includes the motor, a power inverter module, phase current sensors, and a controller which executes the method.

Abstract: In a method for operating an at least three-phase electric machine used as a drive assembly in a motor vehicle, which is actuated via an inverter, the inverter including switching elements in the form of half bridges which are in each case electrically connected to a respective phase of the electric machine, when a first switching element of a first half bridge connected to a first phase is permanently closed/opened on account of failure, a second switching element of the first half bridge is permanently opened/closed and, in a first angular range of an electrical rotation, which is uninfluenced by the first phase, all switching elements of the additional half bridges are actuated in the usual manner.

Abstract: A method for inspecting a wye ring in a generator includes the steps of dismantling the generator to gain access to the wye ring and at least a portion of a rotor, applying a test signal to the rotor and measuring an inductive voltage at two or more locations near the wye ring. A comparing step compares results from the measuring step to determine if a fault exists in the wye ring. A predetermined difference in inductive voltage measurements indicates presence of the fault.

Abstract: There is provided a method for determining an abnormality during operation of a high voltage disconnect switch, the method comprising: determining a current position of an arm of the high voltage disconnect switch operatively connected to a motor, the motor being operated for driving the arm of the high voltage disconnect switch; determining a torque of the motor corresponding to the current position of the arm; comparing the torque of the motor to a torque threshold for the current position of the arm; and outputting an abnormality signal based on the comparison.

Abstract: A system and method for locating inter-turn short circuits or ground faults in a rotor winding of an electrical generator. The method analyzes data from a Recurrent Surge Oscillograph (RSO) test, identifies a spike or anomaly in a reflected RSO signal, determines an elapsed time between a transmitted signal and the anomaly in the reflected signal, calculates a distance along the winding conductor to the inter-turn short circuit or ground fault based on the elapsed time, and uses a geometric model of the winding conductor to identify a location of the fault based on the distance. The location of the inter-turn short circuit or ground fault specifies a coil number, a turn number within the coil and a position within the turn.

Abstract: A method and apparatus are provided for off-line testing of a multi-phase alternating current machine. A method includes determining, at a first rotor position, a physical stator quantity of each stator winding by applying a test signal to each stator winding, and determining a first joint physical stator quantity by summing the determined physical stator quantities of the stator windings. A method includes determining, at a second rotor position, a physical stator quantity of each stator winding by applying a test signal to each stator winding, determining a second joint physical stator quantity by summing the determined physical stator quantities of the stator windings, comparing the second joint physical stator quantity with a previously determined first joint physical stator quantity, and determining a fault condition of said multi-phase alternating current machine if the first joint physical stator quantity differs from the second joint physical stator quantity.

Abstract: In a rotating electrical machine, a conductive foil or conductive rubber is applied to the surface of insulation layer of a conductor series connection area or to the surface of insulation layer of a turn conductor of coils of rotating electrical machine winding, waveforms of grounding voltages of the individual turn conductor portions are measured through the medium of an electrostatic capacitance of the insulation layer of coil conductor series connection area or through the medium of the insulation layer of coil turn conductor, and a partial discharge is measured while measuring a voltage developing in the coil or across a winding turn in the coil from a difference between the waveforms of grounding voltages.

Abstract: An apparatus for measuring electrical parameters for an electrical system measures a first and second parameters of the electrical system between connections to the electrical system. A processor determines a third electrical parameter of the electrical system as a function of the first parameter and the second parameter. Wireless communication is provided between components of the apparatus.

Abstract: A method is provided for current-based detection of an electrical fault in an electrical network of a motor vehicle, the network having at least: one battery, one pulse-controlled inverter, one d.c. voltage converter, and an intermediate circuit associated with the pulse-controlled inverter. The method includes: detecting magnitudes of each a battery current, a d.c. voltage converter current, and an intermediate circuit current; comparing current magnitudes according to provided equations; and checking based on the comparison of whether a specifiable deviation has been exceeded. An alternative method for voltage-based detection of an electrical fault in an electrical network of a motor vehicle includes: detecting magnitudes of each a battery voltage, a d.c. voltage converter voltage, and an intermediate circuit voltage; comparing voltage magnitudes according to provided equations; and checking based on the comparison of whether a specifiable deviation has been exceeded.

Abstract: The method includes operating the synchronous machine in idle operation; recording a phase voltage measured value of the synchronous machine; ascertaining a phase voltage expected value by allocating stored characteristics map values for the phase voltage, for the exciting current and the recorded rotational speed of the synchronous machine; and comparing the phase voltage expected value to the phase voltage measured value. Also described is a diagnostic device for carrying out this method, as well as a corresponding computer program product.

Abstract: An apparatus for controlling a high-power drive device external to a package of a motor drive circuit includes a motor drive circuit. The motor drive circuit includes a driver to control the high-power drive device based on a first reference voltage, a second reference voltage, and a control signal based on a received control signal. A fault circuit generates a failure indicator based on a voltage across terminals of the high-power drive device. A fault condition is based on the failure indicator. A first terminal coupled to the driver charges a node of the high-power drive device over a first length of time in response to an absence of the fault condition and a first level of the control signal. A second terminal coupled to the driver discharges the node over a second length of time different from the first length of time.

Abstract: An interface circuit for detecting a fault in a resolver is provided. More specifically, the interface circuit includes the resolver connected to an intermediate point of a stator coil of a first output terminal for a sine wave signal and an intermediate point of the stator coil of a second output terminal for a cosine wave signal to output the sine and cosine wave signals as a common mode signal. Also includes is resolver fault detection interface unit that adjusts a gain and an offset of the sine wave signal and the cosine wave signal in order to adjust the sine wave signal and the cosine wave signal received as a common mode signal to a frequency that can be suitably applied to an analog/digital terminal of a microcomputer, and to allow high-frequency components of the sine wave signal and the cosine wave signal to pass therethrough.

Abstract: A method for monitoring performance of an electricity generating system of a wind turbine is presented. A set of reference data is provided. The set of reference data is indicative of a correspondence between a performance parameter and at least two operational parameters. Measurement values for the performance parameter and the at least two operational parameters are received. The received measurement values and the set of reference data are compared. It is determined whether the measurement values deviate from the reference data.

Abstract: A rotating electric machine for an electric vehicle, installed in a vehicle and driven by an inverter power source, includes: a partial discharge measuring device that measures partial discharges occurring in insulated areas between windings, between phases and between the rotating electric machine and a ground.

Abstract: An electric-motor drive arrangement is proposed having at least one electric motor and having at least one control device, wherein the electric-motor drive arrangement has a measurement data processing apparatus and a non-volatile memory. In this case, the memory is connected to a comparator which operates at least one optical display block of a display apparatus when a predetermined set value is reached or exceeded.

Abstract: One embodiment is a diagnostic method for a system including setting a first diagnostic code based upon a condition of a DC bus of a variable frequency drive during a first drive state, setting at least one additional diagnostic code based upon a condition of at least one motor phase current during a second drive state, outputting first diagnostic information indicating a malfunction of the variable frequency drive if the first diagnostic code indicates a first error, and outputting second diagnostic information indicating a malfunction of a motor or a connector coupling the motor and the drive if the at least one additional diagnostic code indicates a second error.

Abstract: The control system of the invention includes at least one actuator (6) for a cowling (2), driven by at least one electric motor (7), and control means (9) for the electric motor (7) and the actuator (6). The control system includes an electric circuit (C) that comprises: a plurality of electric components; a plurality of measuring means (16-18) adapted for measuring respectively a characteristic magnitude of an electric component or a group of electric components in the electric circuit; a failure detection means (19) adapted for detecting a failure at a component of the electric circuit when the characteristic magnitude measured at said component exceeds a predetermined value or is in a range of predetermined values.

Abstract: A method and apparatus are provided for off-line testing of a multi-phase alternating current machine. The method comprises determining, at a first rotor position, a physical stator quantity of each stator winding by applying a test signal to each stator winding, and determining a first joint physical stator quantity by summing the determined physical stator quantities of the stator windings. There is also provided a method and apparatus for off-line testing of a multi-phase alternating current machine.

Abstract: An impulse voltage generator uses a predetermined rectangular waveform signal and a high voltage to generate an impulse voltage. The high voltage is obtained by boosting an instruction voltage of the rectangular waveform signal on a per-cycle basis. A partial discharge frequency calculation section receives detection signals based on partial discharges occurring in an object to be measured by the application of the impulse voltage and counts the detection signal on a per-cycle basis as a partial discharge frequency. An application voltage signal observation circuit observes an application voltage signal indicating the impulse voltage applied to the object to be measured. In a first cycle in which the partial discharge frequency reaches a specified frequency or more, a voltage value acquiring section sets, as a partial discharge starting voltage, the peak value of the voltage indicated by the application voltage signal output from the application voltage signal observation circuit.

Abstract: The present invention relates to a detection circuit for detecting coil abnormality of a DC fan motor, which is applied to a fan. The detection circuit comprises at least one detection unit and a processing unit. The detection unit is used to detect and receive the voltage signal at the center point of the coil set of the fan stator and perform a clamping process and a inverting process on the voltage signal to generate an inverted voltage signal such that the processing unit compares the inverted voltage signal with a predetermined value and determines to generate a notifying signal to a remote device. Thus, the effect of effective real-time monitoring the fan can be achieved.

Abstract: A continuity tester that has particular application for inspecting the insulation on the stator windings in an electric machine. The continuity tester includes a power supply, a brush having conductive bristles, and an analog-to-digital (A/D) converter. One terminal of the power supply is electrically coupled to the brush and another terminal of the power supply is electrically coupled to the A/D converter and the stator being tested. The conductive brush is selectively positioned against the exposed windings of the stator, and if an electrical circuit is formed as a result of loss of insulation, the potential at the input of the A/D converter drops, which can be detected. In one embodiment, the conductive brush is a manual brush that is moved across the stator windings, and in alternate embodiments the conductive brush is specially configured to be positioned against the conductive windings in an automated process.

Abstract: A first and/or a second electrical machine is tested using a test apparatus that includes a torque transmitter having torque connections for the first and the second electrical machine and an electrical shaft having respective electrical connections for the first and the second electrical machine. The electrical shaft is designed to transmit at least five times as much electrical power between the respective electrical connections as can be supplied by a supply apparatus of the test apparatus from an external electrical energy source to the electrical shaft. This condition is assumed to be satisfied when the test apparatus lacks such a supply apparatus. A corresponding method using such test apparatus is also disclosed.

Abstract: A method for use in monitoring a synchronous machine includes coupling a power conversion assembly to an electric power source and to a synchronous machine. The synchronous machine includes a plurality of winding inter-turn portions. The method also includes energizing the synchronous machine via the power conversion assembly. The method further includes recording at least one first operational measurement of the power conversion assembly and the synchronous machine. The method also includes calculating a first impedance downstream of the power conversion assembly based on the first operational measurement. The method further includes recording at least one second operational measurement of the power conversion assembly and the synchronous machine. The method also includes calculating a second impedance downstream of the power conversion assembly based on the second operational measurement.

Abstract: A method and a corresponding system for detecting a malfunction in an electric drive unit. The method comprises the following steps: ascertain (S17) a current flow characteristic (1) of an electric drive unit; detect (S33) a gradient change in the current flow characteristic (1) at a first point in time (t=n); compare (S35, S39) the gradient change with a predefinable gradient change range; establish (S45) a malfunction in the electric drive unit if the gradient change is outside the predefinable gradient change range.

Abstract: Systems, methods and apparatus for monitoring rub detection in a machine are provided. An electrical signal may be provided for transmission to and into a component of the machine. A capacitance associated with the electrical signal in the component may be monitored. Based at least in part upon a determined change in the monitored capacitance, a potential rub condition for the component of the machine.

Abstract: A method for monitoring the functioning of an electric motor-driven pump (1), preferably in a vehicle (F), which has an internal electronics system (4) by means of which functional parameters of the pump (1) are monitored. The internal electronic system (4) relays the values of the functional parameters to a central control device (8) via an internal communication interface (6), and the values of the functional parameters are detected and monitored in the central control device (8) with respect to critical limiting values. The change over time of at least one value of the functional parameters is detected in the central control device (8), and a malfunction of the pump (1) is deduced if a value of at least one functional parameter remains constant over a predefined period of time.

Abstract: The system contains a controller unit comprising a memory device, a processing unit, and at least one analog-to-digital converter. A power stage has a plurality of switches, wherein the power stage receives a control signal from the control circuit and a power signal from a power source. The power stage drives two windings of the set of three stator windings to rotate a rotor and maintains one stator winding of the three stator windings undriven. The memory device stores a plurality of values for the driven current and a plurality of demodulated undriven winding voltages. The processing unit compares the plurality of values and periodically calculates a rotor sextant while the rotor rotates. The processing unit compares at least two demodulated undriven winding voltage values corresponding to at least two current values within the rotor sextant to calculate the rotor sextant parity and verify the calculation of the rotor sextant.

Abstract: Methods and apparatus are provided for detecting a phase current sensor fault in a multi-phase electrical motor. The method comprises, receiving an input torque command T* and measuring a set of feedback signals of the motor including a phase current Ix for each of the phases of the motor, generating direct and quadrature command phase currents Id*, Iq* for the motor corresponding to a value of the input torque command T*, determining a total command current Is=[(Iq*)2+(Id*)2]½, generating a negative sequence current Ineg, where for three phases Ineg=(?)[Ia+(?2)Ib+(?)Ic], where ?=ej2?/3, combining Ineg and Is to provide a normalized negative sequence current Inn=Ineg/Is, comparing the normalized negative sequence current Inn to a predetermined threshold value INN* to determine the presence of a phase current sensor fault, and executing a control action when Inn>INN*.

Abstract: Disclosed herein is a system and method for determining faults in motors and drives. The system includes a motor drive that has a DC-link coupled to a power source. A controller system is configured to measure power applied to the DC-link, integrate the power over time to yield energy consumed, and to determine energy that accumulates in operation over time. The controller is further configured to detect a fault condition when the energy that accumulates in operation is less than expected based on the energy consumed.

Abstract: A microcontroller determines the position of the rotor of a brushless, direct-current motor by determining the time of zero crossing of back electromotive force (EMF) emanating from the non-driven phase winding. The zero crossing point is determined by interpolating voltage differentials that are time stamped. Each voltage differential is the difference between the phase voltage of the phase winding and the motor neutral point voltage. The time of zero crossing is determined without using a comparator and without interrupting the processor at each zero crossing point. The processor interpolates the time of zero crossing independently of when the zero crossing point occurs. A hold signal conductor is connected both to a sample and hold circuit and to the load input lead of a time stamp register. The microcontroller simultaneously captures a phase voltage in the sample and hold circuit and a timer count in the time stamp register.

Abstract: A missing stator slot wedge in an electrical machine can be detected by analyzing a current spectrum of the machine in a high frequency area. A current spectrum is provided from a current measurement, and values of the current spectrum in the high frequency area used to determine whether a stator slot wedge is missing or not. The conclusion can be based on values of a relative current amplitude IdB or on presence of certain harmonics in the high frequency area.

Abstract: A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.

Abstract: A motor control diagnostic apparatus is provided. The apparatus includes a control module in communication with a multiple phase electric power steering motor, the control module configured to generate multiple phase duty cycle outputs based on a voltage command generated from a motor torque command and motor position. The apparatus also includes a diagnostic module configured to analyze a reasonableness of the duty cycle outputs based on comparing the duty cycle outputs to expected duty cycle outputs, wherein the expected duty cycle outputs are estimated based on determining the electrical revolution sector of each motor phase.

Abstract: A system and method of predicting motor failure based on relationships of motor pair characteristics, such as temperatures. A motor pair detection module receives temperatures for each motor of a motor pair over a predetermined window. The motor pair detection module determines whether at least one of the temperatures of the first motor and the second motor exceeds a temperature threshold during the predetermined time window. The motor pair detection module further determines whether the temperature of the first motor differed from the temperature of the second motor by at least a difference threshold for at least a percentage threshold of the predetermined time window. Based on the determinations, the motor pair temperature outputs an alarm signal to indicate a potential impending failure of one of the motors of the motor pair.

Abstract: An apparatus for determining alternating current (AC) delay variation of a transistor device under test includes a ring oscillator, the ring oscillator having the transistor device under test configured within a feedback path of the ring oscillator; and circuitry configured to measure a difference between a first signal delay path and a second signal delay path, the first signal delay path being between a gate terminal and a drain terminal of the transistor device under test, and the second signal delay path being between a source terminal and the drain terminal of the transistor device under test.

Abstract: An automated EL CID inspection technique for the stator core of an electrical machine is provided. The inspection device includes a rail, a pickup coil and a coil support assembly. The coil support assembly includes a first part movable along the rail, and a second part where the pickup coil is actually installed. The second part is movable jointly with the first part along the rail, while also being movable relative to the first part in a direction towards or away from the stator core. A motor actuates a motion of the coil support assembly. During inspection, the motor is activated, upon which the coil support assembly moves along the rail while a specified distance is maintained between the stator core and the pickup coil by the relative motion between the first and second parts. The technique is particularly applicable in a step-iron portion of the stator core.