Abstract: Provided is a liquid leakage detection line including: at least two conductors including a first conductor and a second conductor, in which the first conductor and the second conductor are configured to be electrically connected to each other through a liquid. Each of the first conductor and the second conductor is directly covered by a braid including basalt fibers, or the first conductor and the second conductor are indirectly covered by the braid.

Abstract: An insulation resistance detection circuit is coupled to a positive end and a negative end of a DC power source, and is used to detect a positive insulation resistance between the positive end and a ground point and detect a negative insulation resistance between the negative end and the ground point. A detection unit sets a first estimated resistance and a second estimated resistance, and acquires a first voltage based on turning on the switch and acquires a second voltage based on turning off the switch. The detection unit calculates a third voltage and a fourth voltage according to the first estimated resistance and the second estimated resistance so as to detect the positive insulation resistance and the negative insulation resistance when the third voltage is equal to the first voltage and the fourth voltage is equal to the second voltage.

Abstract: A method for monitoring a system for transmitting electrical power for a network for transmitting DC electrical power. The method involves determining, along a measurement segment, a profile of a temperature parameter, determining a theoretical leakage current between the grounding connections of the measurement segment, taking into account the temperature parameter profiles and the load current and voltage, measuring the leakage current between the grounding connections of the measurement segment, and generating an alert if there is a difference between the theoretical and measured leakage current.

Abstract: Insulation monitoring may be provided by a signal generation unit for applying a pulse signal to an electric line; a signal measurement unit for measuring the voltage of an applied pulse signal from the ground, when the pulse signal is applied to the ground through insulation resistance; an average voltage calculation unit for calculating the average voltage of the voltages measured during a period depending on sampling intervals; and a control unit for calculating the sampling intervals on the basis of an initial sampling interval and a preset time multiple, calculating the average voltage during the sampling period according to the calculated sampling intervals, and, according to whether the difference between calculated first and second average voltages measured before the first average voltage is within a first error range, detecting the first average voltage as a normal voltage, or calculating the sampling intervals by applying different time multiples thereto.

Abstract: A conduit for delivering a supply of gas under a positive pressure includes a conduit wall having a first conduit end and a second conduit end. The first conduit end is adapted to be attached to the supply of gas. The conduit wall is deformable between (a) an open condition in which the conduit wall defines a conduit passage along which the supply of gas can travel between the first conduit end to the second conduit end, and (b) a collapsed condition in which the conduit wall substantially collapses the conduit passage.

Abstract: A device is presented for use in power distribution networks, for limiting transient overvoltages during backfeed on a network primary feeder whose feeder breaker is open and whose network protector fails to open. The device is self-contained and self-protecting, and limits the transient voltages due to an arcing single line-to-ground fault by inserting a resistance into the zero-sequence network of the primary feeder. Limiting transient overvoltages reduces damage to and prevents failures of various network components, and in particular, prevents multiple insulation failures during backfeed and reduces failures during backfeed in microprocessor network protector relays on the secondary side of network transformers whose protectors are open. In addition, the device reduces transient overvoltages associated with re-energizing a network primary feeder by closing the station breaker when all network protectors on the feeder are open, as occurs when restoring a network primary feeder that has been out of service.

Abstract: Devices are described that support, house, and protect an electrical cable monitoring system that is electrically coupled to an electrical cable. An example support structure includes an elongate body including an interior surface extending along and concentric to an axis of the electrical cable. The body is configured to engage a cable accessory disposed on the electrical cable. The support structure includes a first electrode attached to the interior surface and configured to operatively couple to the cable accessory. The support structure includes a second electrode attached to the body and configured to operatively couple to the shielding layer. The support structure includes a monitoring device attached to the interior surface and operatively coupled to the first and second electrodes. The monitoring device is configured to monitor one or more conditions of the electrical cable or the cable accessory.

Abstract: The insulation deterioration monitoring apparatus comprises a computer on which software is installed. The software causes the computer to execute at least first to fourth processes. In the first process, during stopping of at least one inverter unit, the computer selects one inverter unit out of the stopped inverter units and causes the inverter corresponding to the selected inverter unit to generate a direct current voltage. In the second process, the computer measures the current value of the ground current while the corresponding motor driving inverter generates the direct current voltage. In the third process, the computer records the measured current value of the ground current for each inverter unit in association with the selected inverter unit. Then, in the fourth process, based on the measured current value of the ground current recorded for each inverter unit, the computer analyzes the tendency of insulation deterioration of each inverter unit.

Abstract: A ground fault detection device includes: a capacitor operating as a flying capacitor; a first switching unit for switching between a state in which a positive electrode side of a battery and a first electrode plate of the capacitor are connected via a resistance, and a state in which the first electrode plate of the capacitor is connected to the ground via a measurement resistance; a second switching unit for switching between a state in which a negative electrode side of a high-voltage battery and a second electrode plate of a detection capacitor are connected with a resistance, and a state in which the second electrode plate of the detection capacitor is connected to the ground via the resistance; a control unit for controlling the first switching unit and the second switching unit; and an offset voltage divider circuit that divides and offsets the voltage generated in the measurement resistance.

Abstract: A ground monitoring tester for an AC power network, the tester comprising: a processor configured to repeatedly conduct impedance measurements of the ground of said AC power network at a point between a neutral reference point and the ground, wherein the processor is configured to conduct the impedance measurements repeatedly at intervals such as between 2 milliseconds and 2 minutes, indefinitely (i.e. without a time limit ending the measurements), whether or not the appliance or system is operational and whether or not there is an indication of a problem in the ground of said AC power network, wherein each of the impedance measurements is based on a voltage differential between a sequence of voltages including a first voltage without an internally generated reference current and a second voltage with an internally generated reference current, and at least one indication output based on the impedance measurements of the ground.

Abstract: An insulation detector for highly accurately detecting or measuring, with a simple configuration, insulation resistance of a load or an apparatus to a ground or a housing and connected to an electric apparatus including one or both of an intra-apparatus capacitor and a battery, the insulation detector including an intra-insulation detector capacitor, a voltage detecting unit that detects a voltage of the intra-insulation detector capacitor, and a current-path forming switch for connecting the ground or the housing, the intra-apparatus capacitor, and the intra-insulation detector capacitor in series and forming a current path including insulation resistance of the electric apparatus. The insulation detector measures the insulation resistance by measuring a time constant of a change in the voltage of the intra-insulation detector capacitor.

Abstract: The present disclosure provides a parameter selection method, apparatus, and computer readable storage medium for an insulation detection circuit. The parameter selection method includes determining an allowable injection frequency range of an AC signal to be injected, according to a predetermined resistance range of an insulation resistance of the power battery under test and a predetermined resistance calculation cycle of the insulation resistance; and selecting an output frequency of the signal generation module according to a lowest frequency to be generated by the signal generation module and the allowable injection frequency range.

Abstract: Methods and devices are provided for testing the function of a standard insulation monitoring device, installed in an ungrounded power supply system, during operation. The basic concept of the invention rests upon adding a testing apparatus to the ungrounded power supply system, which is being monitored using an insulation monitoring device according to regulations, between the active conductors of an ungrounded power supply system and ground, said testing apparatus systematically changing an insulation resistance of the ungrounded power supply system and observing the reaction of the insulation monitoring device in a fully automated manner in perpetually repetitive testing cycles. The power supply system is monitored perpetually during its operation.

Abstract: A light guide is provided. The light guide includes an optic formed along a length of the light guide. In particular, the optic diffuses light incident from a light source, and the optic is formed to gradually change from a first shape to a second shape as the optic gets farther from an incident portion.

Abstract: The invention relates to insulation fault location systems and methods for insulation fault location for an ungrounded DC power supply system, which is redundantly fed from a first direct voltage supply source coupled to diodes and a second direct voltage supply source coupled to diodes and to which a consumer is redundantly coupled. Due to the diode coupling and the asymmetric current splitting of the load current associated therewith, non-compensational partial currents arise in the supply lines in such a power supply system and consequently differential current portions, which can be captured by measuring current transformers and which can interfere with a valid test current during an insulation fault location. In order to eliminate the interfering differential current portions, compensating measures on the primary side are proposed in the measuring current transformers and indirect compensating measures on the secondary side are proposed in an insulation fault location apparatus.

Abstract: A system and method for testing the quality of a conductor is disclosed. Specifically, a system of testing a conductor using voltage source generator that is capacitively-coupled through the conductor to voltage detector is disclosed. The voltage source generates a varying voltage signal which induces a voltage signal in the capacitively coupled microwire conductor. The voltage detector that is also capacitively-coupled to the conductor measures the induced voltage. Using the detected voltage signal, the voltage detector determines whether there are any conductive breaks in the conductor.

Abstract: Disclosed is an apparatus for monitoring a leakage current of a transformer-less photovoltaic inverter, which can reduce the risk of a fault in a grid due to a leakage current in a photovoltaic inverter. The apparatus comprises a low pass filter configured to remove a high-frequency noise of a sensed leakage current signal; an average value calculator configured to calculate an average value of an output of the low pass filter; a direct current component remover configured to subtract the average value from the output of the low pass filter; a phase locked loop circuit section configured to calculate a peak value and a phase of a signal from which the direct current component has been removed; and a resistive component leakage current calculator configured to calculate a resistive component value of a leakage current, based on the peak value and the phase calculated.

Abstract: A partial discharge measurement method includes: a moving step of moving an insulated wire including an insulating layer on a surface of the insulated wire; a voltage applying step of bringing an electrode which is connected to a power supply into contact with the insulating layer of the insulated wire which is moving, and applying a predetermined test voltage to the insulating layer while moving the insulated wire; a detection step of detecting, as a partial discharge signal, a signal which is more than or equal to a threshold value among signals involved in partial discharge events occurring from the insulating layer due to application of the predetermined test voltage; and a determination step of determining, based on a result in the detection step, frequency of occurrence of partial discharge events at the predetermined test voltage.

Abstract: A system and method are described for determining if power lines have been damaged. A virtual circuit is established between a control unit and a remote response unit. A signal is transmitted from the remote response unit responsive to a prior signal transmitted by the control unit. Based on a comparison of measurements of the response signal to expected values, a determination is made as to whether or not the line has been damaged.

Abstract: A battery power supply device includes an alternating-current power source, a secondary cell connected to the alternating-current power source, a first switch for selectively connecting or cutting off a cell and the alternating-current power source, the first switch being disposed between the battery and the alternating-current power source, and a ground fault sensing device for sensing a ground fault in the battery, the ground fault sensing device being connected closer to the battery than the first switch; the ground fault sensing device sensing a ground fault in the battery when the first switch is off.

Abstract: In a high-speed measurement mode, a high-voltage measurement mode (V0 measurement) is omitted and only a negative-pole side ground fault resistor voltage measurement mode (VC1n measurement) and a positive-pole side ground fault resistor voltage measurement mode (VC1p measurement) are performed. In the negative-pole side ground fault resistor voltage measurement mode (VC1n measurement) and the positive-pole side ground fault resistor voltage measurement mode (VC1p measurement), the charging time for the flying capacitor is set to a second predetermined time period that is shorter than a first predetermined time period, which is different from basic operations in a normal measurement mode.

Abstract: The present disclosure provides a method and a device for arc fault detection for a photovoltaic inverter, and a photovoltaic inverter using the same. The method includes: acquiring current signals at a DC side of the photovoltaic inverter; obtaining frequency spectral characteristics of the current signal according to the current signal; judging whether the frequency spectral characteristics of the current signal have a frequency spectral characteristic of an arc; and if the frequency spectral characteristics of the current signal have a frequency spectral characteristic of an arc, shutting down the photovoltaic inverter, acquiring respectively a first input voltage when the photovoltaic inverter is shut down and a second input voltage after a predetermined time period after the shutdown, calculating a voltage drop from the first input voltage to the second input voltage, and judging whether an arc fault occurs according to the voltage drop.

Abstract: A duty ratio calculation section (5a) of this device calculates target duty ratios of respective phases on the basis of a motor current value. When the target duty ratio of an arbitrary phase (U-phase) has become an uncontrolled duty ratio (for example, 5% or lower or 95% or higher), a duty ratio correction section (5b) obtains corrected duty ratios by either adding or subtracting a differential duty ratio, that is, the difference between the target duty ratio of the arbitrary phase (U-phase) and a controllable duty ratio (for example, 0% or 100%), to or from the target duty ratios of the other phases (V-phase, W-phase). A PWM output section (5c) applies a PWM signal, which is based on the controllable duty ratio and the corrected duty ratios, to the power device (3).

Abstract: A charging device for a battery of a vehicle includes an insulation resistance detecting circuit, a charging circuit, a leak current detecting circuit and a decoupling circuit. The insulation resistance detecting circuit includes a coupling capacitor, and is disposed between the battery and a vehicle body for detecting an insulation resistance between the battery and the vehicle body. The charging circuit converts an alternating current supplied from an alternating current source into a direct current and charges the battery in a state without insulting the input terminal and the output terminal and in a state where the vehicle body is coupled to an earth. The leak current detecting circuit detects a leak current between the charging circuit and the earth. The decoupling circuit decouples the insulation resistance detecting circuit from one of the battery and the vehicle body during a charging of the battery.

Abstract: A copper theft alarm system is disclosed. The alarm system can be deployed on existing grain bins or other electrically powered equipment, allowing persons to receive an automated phone call, text message notification, or other desired notification when the system has sensed that a copper cable is being pulled out of a conduit. The notification can aid in potentially disrupting a thief's activity.

Abstract: A method for monitoring an insulation fault in an electric network with at least one electric power system supplying electric power to one or more electric loads, and at least one insulation resistance monitor is provided, wherein the at least one electric power system includes at least one electrical power source, and wherein the at least one insulation resistance monitor monitors an insulation resistance between terminal leads of the at least one electric power source and at least one reference potential. The steps are performed of disconnecting the at least one electric power source from the one or more loads by opening each terminal lead; measuring the insulation resistance between the electric circuit of at least one electrical power source and the reference potential; measuring the insulation resistance for the total electric network; closing the second terminal lead with the first terminal lead open; and measuring the insulation resistance for the total electric network.

Abstract: A method of detecting a wire break in a high voltage generating device that is configured to detect a wire breakage in a low-voltage cable is disclosed. The method of a wire break includes: detecting whether a wire break has occurred in each of the lines in accordance with a combination pattern of whether the time differential value of an IM signal value of a CW circuit obtained when an operating voltage is boosted is positive, negative, or 0, and whether the time differential value of a VM signal value obtained after the operating voltage is boosted by the CW circuit is positive, negative, or 0; and identifying which of the lines is broken.

Abstract: If a charge voltage of a read capacitor Ca measured by a microcomputer 15 is zero, the microcomputer 15 measures a charge voltage of the read capacitor Ca after the read capacitor Ca is discharged and is charged by a charge supply circuit 17 to predetermined potential, measures the same when the read capacitor Ca is isolated thereafter from a discharger of a flying capacitor C1, and measures the same when the read capacitor Ca is charged thereafter with a discharge voltage of the flying capacitor C1 just after the start of discharge of the flying capacitor C1. Based on a pattern of the charge voltage values of the read capacitor Ca measured at the respective time points, a fault location of the insulated condition detector 10 is identified.

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: A Portable Maintenance Aid (PMA) having multiple applications for the electrical testing and data acquisition for various air/ground vehicle platforms is disclosed. The PMA includes an interface adapter that has a number of electrical testing interfaces and data collection ports in addition to a stray voltage detector. The portable testing aid also includes a user interface that transmits data to the interface adapter and a display that communicates the testing and maintenance information to the user. The portable testing aid also includes a communication system for transferring information between the user interface, the display, and the interface adapter. The PMA provides a preload tester/stray voltage tester that is sustainable, less replaceable and has capability of filling the test voids.

Abstract: In a method for detection of an arc in a current path of a converter arrangement (2) for converting a DC input power to an output power, an arc is detected by sensing the current (4) in the current path by means of a current transformer (11), filtering the current signal (4?) with an analog band pass filter (14), converting the analog filtered current signal (4?) into a digital current signal (4??), determining the harmonic content (19) of the digital current signal (4??) and then deciding whether an arc exists if the harmonic content (19) exceeds a threshold, where the threshold is determined at the beginning as a multiple of the average harmonic content during a certain period of time of the current signal.

Abstract: An insulation state detection circuit includes a first charging circuit, a second charging circuit and a third charging circuit. A charging resistance value in the case that a capacitor is charged in the first charging circuit coincides with a charging resistance value in the case that the capacitor is charged in the second charging circuit when a resistance value of the ground fault resistor of a negative terminal side of a DC power source is a ground fault alarm threshold value for an insulation state of an alarm level. The charging resistance value of the first charging circuit coincides with a charging resistance value in the case that the capacitor is charged in the third charging circuit when a resistance value of the ground fault resistor of the positive terminal side is a ground fault alarm threshold value for an insulation state of an alarm level.

Abstract: A method for assessing insulation deterioration in a live underground power cable may include, in one embodiment, attaching a coupling device to a live underground power cable and using the coupling device to couple a test signal onto the power cable. The power cable may carry a normal AC power signal at a first frequency, while the test signal may have a second frequency different from the first frequency. The test signal may be detected after it has traveled a distance along the power cable. It may then be analyzed to determine a change in velocity and/or attenuation of the test signal as a function of the normal AC power signal. The severity of water trees in the power cable may be inferred based on the magnitude of the change.

Abstract: Provided is an insulation resistance measuring circuit including: a source resistor unit including a first source resistor connected between a positive terminal of a battery and a second source resistor and the second source resistor connected between a negative terminal of the battery and the first source resistor; a voltage sensing unit sensing a voltage of the first source resistor as a first voltage and sensing a voltage of the second source resistor as a second voltage; and an insulation resistance measuring unit measuring an insulation resistance of the battery through a value obtained by dividing a difference between the first and second voltages by a sum between the first and second voltages.

Abstract: An insulation measurement apparatus includes a path including a first resistor, a capacitor electrically floated from a ground, and a second resistor between a positive to a negative electrode side of a power supply, a first switching element between the power supply positive electrode side and the capacitor, a second switching element between the capacitor and the power supply negative electrode side, a detection section detecting a charge voltage on the capacitor and determining a power supply insulation state, and a voltage setting section executing a power supply voltage measurement mode controlling the first and second switching elements to charge the capacitor for a predetermined time period, and an insulation voltage measurement mode charging a terminal of a positive or negative electrode side of the capacitor via a resistor between the power supply positive or negative electrode and the ground for a predetermined time period.

Abstract: When, in a state where an AC ground fault occurred on the secondary side of a three-phase inverter circuit, a flying capacitor reaches a continuous charging state while forming a charge circuit including a ground fault resistance due to an AC ground fault, the ground fault resistance due to an AC ground fault is obtained using the same method as that for a positive-side ground fault resistance or a negative-side ground fault resistance due to a DC ground fault. Even if, in the state where the flying capacitor reaches the continuous charging state, a switching duty ratio of respective semiconductor switches of the three-phase inverter circuit varies, a value of a ground fault resistance due to an AC ground fault can be accurately obtained without using the data of the switching duty ratio of respective semiconductor switches of the three-phase inverter circuit.

Abstract: A device for measuring electrical treeing of medium voltage cables. The device includes a plurality of test units connected in parallel. Each test unit includes: a test cup and an insulating base. The test cup includes an inner cavity for accommodating a salt solution, an insulating cover equipped with a first electrode, and an opening. The insulating base includes a side wall, an insulating washer, a second electrode, a conductor, and a through hole from top to bottom. The test cup is disposed on the insulating base. The lower part of the test cup is surrounded by the side wall and presses on the upper surface of the insulating washer. The lower part of the test cup is in threaded connection with the side wall. The space between the opening and the test sample is sealed by the insulating washer.

Abstract: Disclosed is a very low frequency test generator for generating a high voltage having a low frequency in order to test the insulation of capacitive loads, in particular power cables. Said VLF test generator comprises an oscillator part which generates a high voltage that has a high frequency and is modulated with a lower frequency at an output, and a demodulator which is connected to the oscillator part, demodulates the high voltage, and recovers the low frequency therefrom. A discharge resistor for the capacitive load is connected in parallel to the demodulator, said discharge resistor conducting back to the aforementioned output.

Abstract: It is known to insulate bus bars to reduce shock and arc-flash hazards. However, failed or damaged insulation may not be noticed, possibly presenting a greater hazard as it is unexpected and therefore not prepared for. A metal cladding at earth ground enhances the safety to personnel and reduces the likelihood of a more serious line to line arc-flash. Still better is the use of a guard conductor intermediate between the hot conductor and the earth ground insulated from both. Not only does it introduce an additional layer of insulation, it also provides a way to continuously monitor the integrity of the insulation. A resistor divider establishes the nominal voltage on the guard conductor. A departure from nominal voltage indicates a potential fault. The guard conductor can also be used as a node for connecting other sensors, or one of the insulation layers may be of thermally sensitive polymer, to detect hot spots.

Abstract: To detect accurately an insulation fault in a load circuit, Power supply lines and an electric heater (a load circuit) are connected by a detecting portion to detect a detected voltage (detected value) in accordance with the magnitude of a leakage current Id that flows through a ground between the power supply lines and the electric heater, and an evaluation as to whether or not there is a breakdown of insulation of the electric heater relative to the ground is performed by an evaluating portion based on the detected value obtained when the relay contact points are open.

Abstract: A method of evaluating an electrically conductive wire segment having an insulated intermediate portion and non-insulated ends includes passing the insulated portion of the wire segment through an electrically conductive brush. According to the method, an electrical potential is established on the brush by a power source. The method also includes determining a value of electrical current that is conducted through the wire segment by the brush when the potential is established on the brush. The method additionally includes comparing the value of electrical current conducted through the wire segment with a predetermined current value to thereby evaluate the wire segment. A system for evaluating an electrically conductive wire segment is also disclosed.

Abstract: Disclosed is a very low frequency test generator for generating a high voltage having a low frequency in order to test the insulation of capacitive loads, in particular power cables. Said VLF test generator comprises two oscillators, the frequencies of which differ from one another by twice said low frequency, a resonance circuit which is fed in an interfering manner by the oscillators, is adjusted to the oscillator frequencies and causes a voltage rise of the interfering oscillator frequencies, and a demodulator for disconnecting the low-frequency high voltage generated by the interference from the resonance circuit and applying the same to the load.

Abstract: An appliance and a method are intended to monitor a phase line of a section of an electrical energy grid line. The appliance comprises a device for monitoring a parameter of a phase line. The parameter is representative of routine operating conditions of the phase line and has a known propagation speed. The appliance also comprises a device for generating an event detection signal each time the parameter has a value that exceeds a threshold, and for storing a reception time when the detection signal is generated. The appliance also has a device for sending a signal representative of a geographic location of the end of the section and a device for performing a geographic location of the event once two consecutive detection signals are generated from the signal representative of the geographic location, and reception times associated with the two detection signals.

Abstract: An insulation resistance detecting apparatus is provided to detect an insulation resistance of a load circuit. The insulation resistance detecting apparatus includes a coupling capacitor of which a first end is connected to the load circuit; a periodic waveform output section which is connected to a second end of the coupling capacitor, and outputs a periodic waveform to the second end; a waveform shaping section which extracts and amplifies a part of the periodic waveform including a peak point; and an arithmetic operation section which determines the insulation resistance of the load circuit on the basis of a first wave height as a wave height value of a waveform outputted from the waveform shaping section and a second wave height value as a wave height value of the periodic waveform.

Abstract: A circuit, system and method for detecting the presence of a leakage path in a multi-cell voltage source is described. The system includes a detection circuit, the detection circuit having a first amplifier and a second amplifier, a first input of the first amplifier connected to a first terminal of the voltage source and the first input of the second amplifier connected to a second terminal of the voltage source, a second input of each of the first and second amplifiers connected to a reference voltage point, and an output of each of the first and second amplifiers connected to a respective first and second output of the detection circuit; and a processor having inputs connected to the first and second outputs of the detection circuit.

Abstract: A system for the measurement of degradation of electrical wire insulation is described. The system includes an infrared (IR) spectrometer, a fiber optic cable having a first end and a second end, where the first end is configured to interface to the IR spectrometer, and a clamping device for engaging the electrical wire to be tested for insulation degradation. The second end of said fiber optic cable is mounted within the clamping device such that the second end is adjacent the wire insulation.

Abstract: An oil immersed electrical apparatus such as an oil immersed transformer that can detect copper sulfide precipitated on coil insulating paper is provided. In the oil immersed transformer in which a coil with its surface covered by insulating paper is arranged in a container filled with insulating oil, a detection member is prepared by providing two electrodes on a surface of a plate-like pressboard formed of cellulose, which is a same material as that of the insulating paper, this detection member is arranged in contact with the insulating oil, and generation of copper sulfide is detected from reduction in a surface resistance between the electrodes. The temperature of the detection member is set higher than the temperature of the coil so that copper sulfide is generated thereon prior to generation of copper sulfide on a coil unit.

Abstract: An insulation tester for measuring the surface resistivity of a coated electrical steel sheet using a cylindrical electrode that tests the entire surface area of the sheet. A specific voltage is applied across the insulative coating of the electrical steel sheet using the rotatable cylindrical electrode. The cylindrical electrode is roved over the entire surface of the coated electrical steel sheet to detect insulation defects. This roving tester can be used to locate insulation defects in the coating that can cause core failures, or measure the surface resistivity or dielectric strength of the insulative coating. This tester improves over a conventional Franklin tester which uses discrete button electrodes to test only a small portion of the sheet.

Abstract: A test element group (TEG) pattern formed of two wiring patterns alternately disposed in a swirl configuration is used for testing an insulation property of a wafer-level chip scale package (WL-CSP) having a micro wiring such as an inductor element. The insulation property of the WL-CSP can be monitored with enhanced accuracy by measuring a resistance value between solder terminals electrically connected to the swirl-shaped TEG pattern.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for providing connection fault self-monitoring with DC bias current. According to an example embodiment of the invention, a method is provided for obtaining measurements and detecting connectivity faults associated with a voltage mode sensor. The method can include coupling a DC bias current into a circuit. The circuit includes a voltage mode sensor, and the voltage mode sensor can output a time varying signal. The method can also include setting a nominal level of the DC bias current, monitoring a voltage associated with the DC bias current, and determining circuit connectivity status based at least in part on monitoring the voltage.