Abstract: A device for detecting an insulation fault of a direct voltage source that can induce electrocution, including: first and second input terminals for the voltage source; first and third resistive dipoles connected in series between an electric ground and the second input terminal, the first resistive dipole having a resistance at least ten times higher than that of the third dipole; a second resistive dipole and a switch connected in series between the first input terminal and the electric ground; and a detection circuit connected to the terminals of the third dipole, configured to alternately open and close the switch, measure the voltage at the terminals of the third dipole, and determine the amplitude of an insulation fault according to the measured voltages.

Abstract: A system and method for non-intrusive fault detection of a ground fault in a communication channel is provided. A bias voltage may be established on a first portion of the communication channel and a second portion of the communication channel. A first voltage may be detected across a first resistor electrically connected to the first and second portions of the communication channel. Data indicative of whether the ground fault exists in the first or second portions of the communication channel may be provided based on the detecting.

Abstract: The invention relates to a method and a device for determining a maximum leakage current in unearthed power supply networks with a plurality of conductors. The method comprises the steps of: feeding of a measurement signal UP with a measurement frequency fpuls into a conductor arrangement, setting the measurement frequency fPuls, measuring a line-to-line voltage UL-E for each conductor, determining a maximum occurring line-to-line voltage UL-Emax from the measured line-to-line voltages UL-E, determining a voltage UZe across a measurement resistance RM for calculating a leakage impedance ZE, calculating the leakage impedance ZE, and calculating a maximum leakage current THC. The device comprises a signal generator for feeding in the UP with the fPuls, a network coupling circuit between the signal generator and the conductor arrangement, a voltage measuring circuit for measuring the UL-E, and an impedance measuring circuit for determining the Ze by means of the determining of the UZe.

Abstract: The method determines shunt caused residual voltages and fault caused residual voltages on the upstream bus and the downstream bus of the line segment within a faulty feeder section of a faulty feeder. The line segment is designated as a faulty line segment when a reference angle of a faulty phase is between a first angle of a difference between an angle of the fault caused residual voltage and an angle of the shunt caused residual voltage on the upstream bus and a second angle of a difference between an angle of the fault caused residual voltage and an angle of the shunt caused residual voltage on the downstream bus. The location of the fault is determined at a point on the faulty line segment with a difference between the angles of the fault and the shunt caused residual voltages in phase with the reference angle.

Abstract: The present disclosure relates generally to a facilitated method for accurately measuring the earth ground resistance of a ground rod, in particular a footing of a pylon acting as a ground rod or a ground rod attached to the footings of a pylon, and obtaining an overall value for the resistance of the pylon. A method of determining the earth ground resistance of two or more pylon footings is provided according to the present disclosure, comprising conducting selective measurements of each footing of a pylon consecutively and wherein true values for the resistance of each footing measured are calculated. According to the present disclosure, the testing means is connected directly to two auxiliary electrodes which are placed at predetermined distances from the pylon, and a current measurement means which is placed around a pylon footing in order to measure the current flowing along the footing.

Abstract: A device and method for estimating resistance of a ground connection of an electrical apparatus connected to an electrical power network, also connected to ground by an additional resistance, and including at least one impedance disposed at an input of the electrical apparatus, a voltage generator connected to the impedance and connected to ground, a mechanism to measure current flowing to ground, and a calculation mechanism to estimate the resistance of the ground connection as a function of the current flowing to ground. The device and method can for example find application in estimation of resistance of a ground connection of a charger of an electric or hybrid traction motor vehicle.

Abstract: A capacitance detecting circuit includes a constant current source supplying a constant current to a voltage detection point, a time measuring unit measuring time of charge until the voltage of the voltage detection point reaches a prescribed voltage, a storage unit and an operation unit. The storage unit stores first data obtained in advance concerning the time of charge of a capacitance element having a known capacitance value, and second data obtained in advance concerning the time of charge of a capacitance component. The operation unit generates third data representing the time of charge of an object of detection from a difference between the first measurement value of the time measuring unit when the capacitance component is connected to the voltage detection point and the second data, and based on the ratio between the third data and the first data and the known capacitance value, calculates the capacitance value of the object of detection.

Abstract: A vehicle includes a traction battery to propel the vehicle. The traction battery includes a plurality of cells that are each selectively connected to a resistor. A controller or controllers are provided that are configured to control the charging and discharging of the cells. The controller or controllers command the battery or a selected group of cells of the battery to discharge in response to a fault or triggering condition. The discharge enables the battery or the group of cells to achieve a state of charge of approximately zero or less.

Abstract: A ground fault detector which does not need complicated circuitry and can detect a ground fault with high accuracy in conformity to a capacitance of a common mode capacitor is presented. Upon judging the ground fault on the basis of a threshold for a high-tension power supply system which is electrically isolated and mounted in a vehicle, a controller in a ground fault detector alters the threshold in conformity to a capacitance of a common mode capacitor of which value is different between a first state that a system main relay is ON and a second state that the system main relay is OFF, thereby judges the ground fault on the basis of the altered threshold. Thus the ground fault detector can adequately detect the ground fault in conformity to the capacitance of the common mode capacitor. Thus the detector can detect the ground fault with accuracy without complicated circuitry.

Abstract: Disclosed herein is an oscillation circuit including: a control transistor changing an electric potential at an output terminal thereof by proceeding to one of a conduction state and a non-conduction state in accordance with an electric potential at an input terminal thereof; a transistor as an object of a measurement having a polarity of a channel identical to that of the control transistor, and connected in series with the control transistor between a power source and a ground; a capacitor delaying the change in the electric potential at the output terminal in accordance with a value of a leakage current leaked from the transistor as an object of a measurement when the control transistor proceeds from the conduction state to the non-conduction state; and an inversion circuit inverting the electric potential at the output terminal, thereby feeding the inverted electric potential back to the input terminal.

Abstract: An electric leakage detecting apparatus includes: a first voltage-dividing circuit; a second voltage-dividing circuit; a first switch which is inserted in a line connecting the first voltage-dividing circuit and the ground connection resistance; a second switch which is inserted in a line connecting the second voltage-dividing circuit and the ground connection resistance; a first voltage detecting circuit which detects an output voltage of the first voltage-dividing circuit; a second voltage detecting circuit which detects an output voltage of the second voltage-dividing circuit; and a judging circuit which judges whether the electric leakage of the high voltage battery occurs or not on the basis of the output voltage of the first voltage-dividing circuit in a case that the first switch is in ON state and the output voltage of the second voltage-dividing circuit in a case that the second switch is in ON state.

Abstract: In a process plant, a first series of measurements from a coupling interface are received. The first series of measurements are stored. A second series of measurements from a coupling interface are received. The second series of measurements. The first series and second series of measurements are compared. An indication of loss of clamping force is generated if the first series of measurements deviates from the second series of measurements.

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: An insulating state detection unit is configured to perform failure detection for switches, which connect a flying capacitor to a sample hold circuit for acquiring a charge voltage and a ground potential, by using a failure determination threshold value according to a variable value. That is to say, the insulating state detection unit is configured to decide the failure determination threshold value by taking, as a reference, a charge voltage of a capacitor of the sample hold circuit charged with electric charge amount corresponding to a charge voltage of the flying capacitor when the flying capacitor is charged with electric charge amount corresponding to an output voltage of a DC power supply.

Abstract: A method for enhancing the reliability of generator ground fault detection based on a signal injection scheme, wherein the generator includes a winding. The method includes injecting a test signal at a predefined frequency to the winding, measuring an electrical quantity of a response signal in the winding resulted from the injected test signal, and detecting a ground fault based on the measured value of the electrical quantity. The method further includes continuously determining the frequency of the response signal, and discarding the present measured value corresponding to the determined frequency when the determined frequency deviates from the predefined frequency with a first threshold value.

Abstract: The present invention is directed to an electrical wiring device that includes a test circuit that is configured to generate a recurring simulated fault signal. A detection circuit is configured to generate a test detection signal in response to the recurring simulated fault signal. An end-of-life monitor circuit is configured to generate an end-of-life detection signal if the test detection signal is not generated within a first predetermined period of time. At least one indicator is configured to emit an indication signal in response to the end-of-life detection signal. A response mechanism is configured to decouple the plurality of line terminals from the plurality of load terminals after a second predetermined period of time has elapsed following the end-of-life detection signal.

Abstract: In a process plant, a first series of impedance measurements from a valve body are received. The first series of impedance measurements are stored. A second series of impedance measurements from the valve body are received. The second series of impedance measurements from the valve body are stored. The first series and second series of impedance measurements are compared. An indication of loss of integrity of the valve body is generated if the first series of impedance measurements deviates from the second series of impedance measurements.

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 HRG ground fault detector and method for detecting a ground fault in a High Resistance Ground (HRG) system are provided. The HRG ground fault detector in one example embodiment includes a first input A coupled to a first phase PHA of the HRG system, a second input B coupled to a second phase PHB, and a third input C coupled to a third phase PHC, with the HRG ground fault detector generating a simulated neutral voltage VN? from the first phase PHA, the second phase PHB, and the third phase PHC, wherein the simulated neutral voltage VN? comprises a zero voltage potential when the first phase PHA, the second phase PHB, and the third phase PHC are equal, comparing the simulated neutral voltage VN? to a predetermined fault voltage threshold, and detecting a HRG ground fault if the simulated neutral voltage VN? exceeds the threshold.

Abstract: A method and device for detecting an electrical continuity fault between a first and a second points of a network of metallization strips, including determining, from mapping, a length or a duration of a shortest path between the first and the second points, sending, at the first point, a signal in the network, detecting, at the second point, the signal sent, measuring a duration between the sending and the detection of the signal, knowing the speed of propagation of the signal in the metallization strips, determining the presence of at least one electrical continuity fault if the distance travelled calculated from the measured duration is different from the length of the shortest path determined from the mapping or if the measured duration is different from the duration to travel the shortest path determined from the mapping.

Abstract: Exemplary methods are directed to insulation monitoring of non-grounded electrical DC power supply systems and AC power supply systems which have a resistive (Rf) and capacitive (Cf) insulation impedance between the power supply system and ground. The method includes applying a pulsed AC voltage (U0) having alternately different pulsed voltage values to the power supply system to be monitored via a resistive system interface (Ri) between the power supply system and ground. The insulation impedance (Rf) between the power supply system and ground is determined using time profiles of transient processes of the measurement voltage (Vm) prior to transient recovery of the power supply system to the respective pulsed voltage value (U0) of two polarity-inverted pulsed voltage value application processes.

Abstract: An antenna (L) diagnostic device of a resonant circuit associated with an amplifier includes a first transistor (HS1) and a second transistor (LS1) connected and an amplifier output (OUT1). The first transistor (HS1) and the second transistor (LS1) are mounted symmetrically and the amplifier output (OUT1) is located between the two transistors. The device includes: elements for measuring a current flowing in a connection of each of the transistors; first elements for generating an input signal connected to the first transistor; second elements for generating an input signal connected to the second transistor; and electronic elements (8) with an output supplying an output signal representative of the potential (V_OUT1) at the amplifier output. A method for diagnosing an antenna implementing such a device is also described.

Abstract: An alarm system for alarming whenever there is a power leakage from an electronic device, includes a voltage decreasing circuit, a switch circuit and an alarm circuit. The voltage decreasing circuit receives a first voltage from a live wire output terminal and outputs a second voltage. The switch circuit outputs a control signal when the power leakage is detected. The switch circuit is electrically connected to a connection port. The connection port is electrically connected to the live wire output terminal and a neutral wire output terminal. The alarm circuit receives the control signal and alarms. If there is power leakage from the electronic device, the first voltage from the live wire input terminal flows into the ground wire input terminal via the electronic device; the switch circuit turns on and the alarm circuit is closed to alarm.

Abstract: A method for detecting predetermined fault conditions associated with the supply of AC electrical power to a consumer, the supply having an active conductor and a neutral conductor with the neutral conductor being connected to earth. The method comprises providing a first current detector associated with the active conductor; providing a second current detector associated with the neutral conductor; providing a voltage detector to detect voltage between the active conductor and the neutral conductor; and checking a current ratio of neutral current to active current whereby the current ratio is indicative of a predetermined fault condition. Also disclosed is a method of checking the condition of supply line active and neutral conductors in a consumer's supplied premises including determining the impedance of the active conductor and the impedance of the neutral conductor to indicate the condition of each of the active and neutral conductors.

Abstract: A method and an apparatus for detecting an earth fault on a three-phase electric line are provided. The apparatus includes means for determining a neutral admittance on the basis of a residual current and a residual voltage, means for comparing the determined neutral admittance to a predetermined operation characteristic to detect an earth fault on the three-phase electric line, and means for determining one or more harmonic components of the residual current and one or more harmonic components of the residual voltage. The harmonic components have frequencies n*fn such that n?2 and fn is a fundamental frequency. The means for determining a neutral admittance are configured to use at least one of the determined one or more harmonic components of the residual current and at least one of the determined one or more harmonic components of the residual voltage for determining the neutral admittance.

Abstract: A signal generation module injects a signal in a pilot conductor with a DC component and one or more AC components. Pilot conductor current is injected in a grounding conductor of power cables connecting power source to load. A current monitor module monitors current in the pilot conductor or ground return, a DC detection module determines DC current present in the monitored current, an AC detection module determines AC current corresponding to each frequency of the AC components in the monitored current, a DC minimum threshold module determines if the DC current is below a DC current minimum threshold, an AC threshold module determines if any of the AC currents is below an AC threshold, and a trip module opens a contact after determining that the DC current is below the DC current minimum threshold or that at least one of the AC currents is below an AC threshold.

Abstract: A circuit interrupting device having an auto-monitoring circuit for periodically testing various functions and structures of the device. The auto-monitoring circuit initiates an auto-monitoring routine which, among other things, generates a self-test fault condition and determines whether the detection mechanisms within the device properly detect the self-test fault. A test fault circuit is configured to generate one or more test pulses that cause the self-test fault condition and the test pulses are generated to occur outside of an active region of the fault detection circuit.

Abstract: A watchdog apparatus for monitoring ground current is disclosed. A system and method also perform the functions of the apparatus. The watchdog apparatus includes a watchdog signal module that generates a watchdog signal. The watchdog signal is generated at a specific interval and includes an identifiable characteristic. The watchdog signal module is part of a device being monitored for functionality. The apparatus, in some embodiments, includes a signal monitoring module that determines if the watchdog signal includes the identifiable characteristic, and an alert module that sends and alert signal in response to the signal monitoring module determining that the watchdog signal does not include the identifiable characteristic.

Abstract: Systems or methods for testing performance of an isolation monitor for a vehicle having a high voltage traction battery electrical system isolated from a low voltage electrical system include a device for connecting to an isolation/leakage monitor under test. The device includes a current leakage bus, a current leakage array, and a current leakage destination with associated switching elements automatically controlled by a programmed microprocessor to introduce various leakage impedances to a second voltage source or ground and to evaluate performance of the isolation/leakage monitor under test.

Abstract: A test carrier 10A comprises: a base board 21A which holds a die 90; and a cover board 31A which is laid over the base board 21A so as to cover the die 90. The test carrier 10A comprises a seal member 24 which is interposed between the base board 21A and the cover board 31A and which surrounds the die 90.

Abstract: An apparatus and method for detection and adaption to an end-of-line resistor in a NAC of a control panel or power booster of, for example, an alarm system and for ground fault localization in the alarm system are provided. The apparatus can include a notification appliance circuit, where the notification appliance circuit includes first and second analog input terminals, where the notification appliance circuit includes first and second external output terminals, and where the notification appliance circuit includes an end-of-line resistor. Current can be driven through the notification appliance circuit via the first and second analog input terminals, and voltage can be measured at each of the first and second external output terminals. The measured voltage can be indicative of one of a value of the end-of-line resistor or that a state of the notification appliance circuit is one of open, shorted, ground faulted, or normal.

Abstract: A system and method for detecting excess voltage drop (EVD) in a three-phase electrical distribution circuit includes a diagnostic system comprising a processor that is programmed to receive three-phase voltages and currents provided to terminals of the electrical machine, determine fundamental components of the three-phase voltages and currents provided to the terminals, and compute positive, negative, and zero sequence currents from the fundamental components.

Abstract: A device for monitoring a neutral grounding resistor (NGR), including first and second NGRs electrically connected in parallel, a rectifier circuit electrically connected in series with the second NGR and a voltage source and a logic resistor electrically connected in series with the second NGR. A logic circuit measures current passing through the logic resistor and determines the resistance of the first NGR based on the measured current and the resistance of the second NGR. As such, a failed-open or failed-short condition of the first NGR may be identified based at least in part on the determined resistance of the first NGR.

Abstract: An earth ground testing cable is configured to electrically couple an electrode to a measurement unit. The cable may comprise an outer surface having at least a first marking and a second marking. The first marking and the second marking define a segment of cable having a length that corresponds to a spacing distance between the electrode and at least one other electrode for performing an earth ground test. The spacing distance may be determined based on electrical interference properties of a measurement unit and the one or more electrodes. The ground earth testing cable may be part of a system and may be used to determine positioning for electrodes. The cable may also couple an electrode to the testing unit, so that an earth ground reading is determined.

Abstract: A test system for testing a sensor system includes a high-impedance resistor for forming a voltage divider with any corrosion or foreign substance that might be present between a signal conductor and a ground conductor. While a voltage is applied across the voltage divider, the voltage can be measured across the high-impedance resistor for determining whether an undesirable amount of conductance exists between the signal wire and ground. The test system also includes switching means for switching between any number of signal wires of a system undergoing testing.

Abstract: A secure system for charging a battery of a motor vehicle from a power supply network, which system is in a vehicle and includes a mechanism measuring frequency of the network, an injection mechanism injecting current pulses into the network, a mechanism measuring voltage between the ground and a neutral of the network, an analog filter filtering the measured voltages at high frequencies, a digital filter filtering the analog-filtered voltages at low frequencies, and a mechanism determining resistance between the ground and the neutral of the network on the basis of the digitally filtered voltages and an amplitude of the current pulses. The digital filter includes a mean value filter which determines a mean value based on N voltage measurements spaced apart by a time interval T+T/N, where T is the period of the network determined by the mechanism measuring the frequency of the network.

Abstract: Ground Potential Rise (GPR) systems and methods with depth sensing measure the GPR between the ground grid and the remote earth. Methods and systems described herein may provide a GPR measurement to an existing distance protection. A GPR system may comprise a set of potential transformers. The set of potential transformers may be coupled to different ground rods driven into the earth at different depths, respectively. One wire of the high voltage side of the potential transformer may be coupled to the ground grid of a substation, and the second wire of the potential transformer may be coupled to an insulated wire that is coupled to a ground rod or multiple of ground rods bonded together. The low voltage side of the potential transformer is used to connect Distance Relays, Voltage Relays, DFR or Alarms.

Abstract: The present techniques include methods and systems for detecting the grounding condition of an electrical system to automatically determine a suitable electrical drive configuration. The drive includes a test resistor which may be connected or disconnected from the drive to measure different drive voltages. The measured drive voltages are analyzed to determine a type of grounding configuration of the electrical system in which the drive is to be installed. Embodiments also include determining ground resistance condition such as a high resistance ground (HRG) fault or a ground resistance fault when the drive is in operation.

Abstract: A ground leakage current measurement apparatus in an ungrounded DC power system including positive and negative electric lines includes a switching unit configured to perform switching to supply measurement power to a positive side ground resistor and a negative side ground resistor by using power of the electric lines; a measurement unit connected between the switching unit and the ground and configured to measure at least one of positive and negative side ground leakage currents; and a control unit configured to control the switching unit to discriminate a positive side ground leakage current operation and a negative side ground leakage current operation of the measurement unit.

Abstract: The device according to the invention for estimating the impedance of an ground connection, the ground connection being connected to the ground of an alternating electric network (14) comprising a phase connected to an electric phase conductor and a neutral connected to an electric neutral conductor, comprises: an electrical component having a predetermined value impedance positioned between the phase conductor and the ground connection; a first sensor capable of measuring a first value of a first property between the phase conductor and the ground connection and a second value of the first property; a second sensor capable of measuring a first value of a second property between the neutral conductor and the ground connection and a second value of the second property; and a computation member computing the impedance of the ground connection.

Abstract: A method of detecting a short circuit affecting a sensor, at least one terminal of the sensor being connected to a bias resistor, includes: applying to at least one bias resistor at least one test bias voltage having at least one predefined characteristic that is different from a corresponding characteristic of a nominal bias voltage of the resistor; measuring a resulting differential voltage across the terminals of the sensor; and as a function of at least one characteristic of the measured differential voltage corresponding to the predefined characteristic of the test bias voltages, determining whether the sensor presents a short circuit.

Abstract: A ground leakage detector for detecting a ground leakage in an electric vehicle including a battery, and a charging connector which is electrically connectable to a terminal member formed at one end of an outside electric wire through which electric power is supplied from outside to the battery, includes a connector connection section electrically connectable to the charging connector; a contactor configured to contact a vehicle body ground location in the electric vehicle; and a detecting circuit for detecting whether or not there is a ground leakage from the battery to the vehicle body ground location, based on a current flowing between the connector connection section and the contactor.

Abstract: A ground fault detection apparatus is an apparatus detecting a ground fault in an ungrounded AC circuit in which a single-phase three-wire AC power source is connected to a load via a U phase wire, a neutral wire, and a V phase wire, including two resistive elements having an identical resistance value, one terminals of the two resistive elements being connected to the U phase wire and the neutral wire, respectively, the other terminals thereof being connected to each other. The ground fault detection apparatus further includes a current detector detecting a value of a current flowing between the other terminals of the two resistive elements (i.e., a node N1) and a ground point. In a case where the absolute value of the current exceeds a threshold value, the ground fault detection apparatus determines that a ground fault occurs.

Abstract: An apparatus and method for detecting faults in a two-wire electric power line isolated from ground includes substantially identical high impedance voltage dividers connected between each of the two wires of the power line and ground, circuits for carrying the output voltages from each voltage divider, a circuit for comparing the output voltages, and outputting a fault signal indicative of a ground fault.

Abstract: Methods and apparatus provide for: measuring leakage current from a source of AC power, which provides power to at least one load circuit; and comparing the measured leakage current values against one or more predetermined thresholds to establish status therefor; and automatically performing self tests to determine whether the leakage current sensing and comparing operations are operative.

Abstract: A signal is conducted from a controller module onto a network via a first coupling. The signal is transmitted across the network and received at one or more receiver modules via one or more second couplings. At the one or more receiver modules, the received signal is analyzed and based upon the analysis, a determination is made as to whether a fault has occurred in the network and/or where the occurrence occurred.

Abstract: An insulation state detecting device includes a positive side input terminal connected to a positive side power line of a high voltage DC power supply, a negative side input terminal connected to a negative side power line of the high voltage DC power supply, a ground electrode, a controller that detects insulation states between the positive side power line and the negative side power line and the ground electrode based on a charge voltage of a flying capacitor, and an equilibrium state forming circuit that promotes an operation of transiting a charge state of a positive side electrostatic capacitance between the positive side power line and the ground electrode and a charge state of a negative side electrostatic capacitance between the negative side power line and the ground electrode from non-equilibrium states to equilibrium states.

Abstract: A circuit configuration monitors the electrical insulation of an electrically conductive part in relation to a first pole and a second pole of an electrical power network for example, an electrical drive network in a hybrid vehicle. The circuit configuration is characterized in that between the electrically conductive part and the two poles, a voltage divider having at least two resistors is arranged in each case. A measuring unit is associated with each of the two voltage dividers and provided for measuring a partial voltage, which drops via at least one of the resistors. A switch unit is associated each with the two voltage dividers and is provided for alternately bypassing at least one of the resistors.

Abstract: A monitor for monitoring isolation resistance, impedance, or other isolation reflective conditions between vehicle systems as contemplated. The monitor may be useful in assessing insulation resistance between a high-voltage power net and a low-voltage power net. The monitor may be configured to assess a sufficiency of the insulation resistance based on a frequency response of the high-voltage power net.

Abstract: An electric leakage sensing apparatus includes a coupling capacitor having one end connected to a DC power supply, a pulse generator that supplies a pulse to the other end of the coupling capacitor, a voltage detector that detects a voltage at the coupling capacitor charged by the pulse, an electric leakage determination part that compares the voltage detected by the voltage detector to a threshold value, and makes a determination of existence or non-existence of an electric leakage of the DC power supply based on a comparison result, and a booster circuit that applies a boosted pulse voltage to the coupling capacitor. The pulse generator converts an output voltage of the booster circuit into the pulse voltage. The voltage detector includes an offset voltage generating circuit that generates an offset voltage.