Abstract: Disclosed are apparatus, methods, and systems for the monitoring of grounding components in an electrical system. Methods of monitoring grounding components comprise a signal or plurality of signals imposed on a ground loop circuit by a first inductive element, a second inductive element which receives the signal(s), and circuitry which compares changes in the imposed signal(s) to a baseline to calculate impedance. Active monitoring of impedance enables contractors to ensure installation of a grounding system was performed correctly, and allows a user to track changes in impedance over the life of the electrical system such that, if an impedance threshold is reached, appropriate action may be taken.

Abstract: An inverter includes two input lines for connecting the inverter to an AC power source, a buffer capacitance effective between the input lines, a grounded potential equalization busbar, an isolation monitoring device monitoring the electrical isolation of one of the two input lines with regard to the potential equalization busbar, and an overvoltage eliminating device having at least one overvoltage eliminator for draining overvoltages from the input lines to the potential equalization busbar. The at least one overvoltage eliminator is connected between that input line, whose electric isolation with regard to the potential equalization busbar is monitored, and the potential equalization busbar, without any fuse being connected in series with the at least one overvoltage eliminator. Any overvoltage eliminator of the overvoltage eliminating device, which is connected between the other of the two input lines and the potential equalization busbar, if present, is connected in series with a fuse.

Abstract: The present invention is implemented by deploying an enhanced ground fault detection and location apparatus and by using the apparatus in conjunction with specific circuit analysis methods, using the information generated by the ground fault detection and location apparatus. The ground fault detection and location apparatus comprises the functionality of a voltmeter, an ammeter, a phase angle meter, a frequency generator, and a variable power supply, thereby providing for a variety of signals and analyses to be performed on a unintentionally grounded circuit in an ungrounded AC or DC power distribution system. The ground fault detection and location apparatus is capable of operating in six different modes, with each mode providing a different capability or opportunity for detecting, analyzing, and locating one or more unintentionally grounded circuits in an normally ungrounded AC or DC power distribution system.

Abstract: A method for operating a ground fault circuit interrupter. In accordance with an embodiment, an operating parameter of the ground fault circuit interrupter can be adjusted in response to an alternating current line signal and a reference signal. In accordance with another embodiment a plurality of indicator signals are generated in response to an alternating current signal. The indicator signals are used to generate one or more control signals and at least one of the control signals is used to control a control a ground fault circuit interrupter.

Abstract: A circuit interrupting device, such as a GFCI receptacle device, is provided that automatically resets itself when power is initially applied to the device, for example, when the device is first installed or when power is reapplied after a power outage occurs. When power is applied correctly to the line side of the device, as opposed to the load side, a voltage is generated that turns on a switching device. Turning on the switching device allows a low level of electric current to flow which, in turn, allows a higher level electric current to flow which closes the latching mechanism of the device and places the device in the reset condition.

Abstract: The present invention is directed to an electrical wiring device that includes a circuit coupled to the line terminals and configured to conduct a predetermined current flow when the line terminals are connected to a source of AC power, the predetermined current flow does not simulate a fault condition. An interrupting contact assembly includes four sets of interrupting contacts that are configured to provide electrical continuity between the line terminals, the load terminals and the at least one receptacle in a reset state and configured to interrupt the electrical continuity in tripped state. The interrupting contact assembly is energized to effect the tripped stated and substantially deenergized otherwise, the interrupting contact assembly being substantially prevented from effecting the reset state absent the predetermined current flow.

Abstract: A device is provided for use with an AC power system having a line conductor, a neutral conductor and a transformer, the line conductor and the neutral conductor are coupled between a source and a load, and the transformer includes a first primary winding coupled in series with the line conductor, a second primary winding coupled in series with the neutral conductor, and a secondary winding. The device includes a first circuit coupled to the secondary winding, providing a first detection signal if a current from the line conductor to ground exceeds a first predetermined threshold, and a second circuit coupled to the secondary winding, having a source that provides an AC signal at a specified amplitude and a specified frequency to the secondary winding. The second circuit provides a second detection signal if an impedance between the neutral conductor and ground is less than a second predetermined threshold.

Abstract: There is a fault circuit interrupter comprising at least one grounded neutral sensor and at least one test circuit configured to test the grounded neutral sensor. A further embodiment can also include at least one fault circuit which is configured to detect a current sent from the grounded neutral sensor. The device can also include a line side phase line, a line side neutral line, and a test line coupled to the line side neutral line and extending from a first region on the line side neutral line to a second region on the line side neutral line, with the grounded neutral sensor being positioned between the first region and the second region on the line side neutral line. This test circuit can comprise a switch, such as a manually operatable switch or it can comprise any one of solid state circuitry, a transistor, and/or a silicon controlled rectifier.

Abstract: An abnormality detection circuit monitors the sink current Irnf of a H-bridge circuit and determines the presence of an abnormal state if the sink current is not detected for a predetermined time. The abnormality detection circuit includes a clock pulse generator, a counter and a NMOS transistor. The abnormality detection circuit includes a clock pulse generator arranged to generate a clock pulse of a predetermined frequency, and a counter arranged so that a count value is incremented every time the clock pulse is provided to the counter and arranged so that the count value is reset when the sink current is detected. The counter generates a first abnormality detection signal that changes from a normal logic level to an abnormal logic level when the count value reaches a predetermined value without being reset.

Abstract: An electrical power protection system, includes a generator configured for supplying Direct Current (DC) power to a load bus, the load bus in electrical communication with a bus circuit; a generator control unit being configured for regulating the output voltage supplied by the generator; a bus contactor in serial communication with the bus circuit, the bus contactor including logic circuits configured for detecting an overcurrent in the bus circuit, the overcurrent representative of a ground fault in the bus circuit; and a capacitor bank coupled to the generator for selectively supplying an excitation voltage through a diode switch to the generator during the ground fault in the bus circuit.

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 method and circuit for determining a circuit element parameter in a ground fault circuit interrupter circuit. An electrical signal provided to a first node is used to generate another electrical signal at a second node. The electrical signal at the second node is multiplexed with a modulation signal to generate a modulated signal that is then filtered and converted into a digital representation of a portion of the circuit element parameter. The electrical signal at the second node is multiplexed with the modulation signal after it has been phase shifted to produce a modulated signal that is filter and converted into a digital representation of another portion of the circuit element parameter. In another aspect, a slope based solenoid self-test method is used for self-testing in a GFCI circuit. Alternatively, a method for determining a wiring fault is provided using a digital filter.

Abstract: A ground fault circuit interrupter (GFCI) device with self-test function includes: hot and neutral conducting circuits; an fault detection circuit responsive to a fault in the hot and neutral conducting circuits to generate a fault detection signal; a signal driving circuit responsive to the fault detection signal to generate a drive signal; a disconnecting mechanism for disconnecting electrical connections in the hot and the neutral conducting circuits when the drive signal exceeds a predetermined level; a self-test circuit for generating a self-test signal according to a predetermined time period and when an alternating current of the power source passes zero points, generating an evaluation result based on the self-test signal and a feedback signal of a fault detection signal corresponding to the self-test signal, and generating error signals if the evaluation result indicates a circuit error; and a device-state indicator circuit for generating alarms based on the error signals.

Abstract: A control and protection system has a DC terminal (DCT), for connection to a DC bus (DCB), a load terminal (LT) for connection to a LOAD, a ground terminal (GT) for connection to an external ground bus (EGB), and an INPUT terminal for receiving ON/OFF commands. An internal ground bus (IGB) of the system is normally coupled to the EGB via the GT. But if a ground fault disconnects the GT from the EGB, the system automatically couples the IGB to the LT, thereby providing a synthetic ground that facilitates continued operation of the system and any peripheral circuits coupled between the DCB and the GT. Any peripheral circuit current passing through the system to the EGB is prevented from causing improper operation of the LOAD by automatically adjusting a series impedance that it passes through between the GT and the LT before reaching the LOAD and EGB.

Abstract: The present invention is directed to an electrical wiring device including a plurality of line terminals configured to be connected to a source of AC power, and a plurality of load terminals. A detection assembly is coupled to the plurality of line terminals and the plurality of load terminals. The detection assembly is configured to detect a wiring state associated with the plurality of line terminals and the plurality of load terminals. The detection assembly includes a primary wiring state detection circuit, a secondary wiring state detection circuit, and an isolation circuit disposed therebetween, the isolation circuit being configured to electrically isolate the line terminals from the secondary wiring state detection circuit in the tripped state.

Abstract: A trip unit includes a current sensor to sense a value of current flowing through a conductor, a circuit to receive first frequency pulses having a number of first frequencies from the conductor, a transmitter to transmit second frequency pulses having a second frequency different than the first frequencies to the conductor, and a processor having a routine. The routine inputs the sensed value of current from the current sensor, determines if the sensed value of current exceeds a predetermined value and responsively causes the transmitter to transmit the second frequency pulses having the second frequency to the conductor, monitors within a predetermined time after determining that the sensed value of current exceeds the predetermined value if a number of the first frequency pulses having the number of first frequencies is received by the circuit, and responsively delays outputting a trip signal, and, otherwise, immediately outputs the trip signal.

Abstract: A direct current feeder protection system includes six conductors, four current sensors sensing four currents flowing in four of the conductors, four circuit interrupters interrupting currents flowing in the four conductors, and a processor cooperating with the current sensors to input four sensed currents, and to output a number of commands to the circuit interrupters. The processor includes a routine detecting a number of: a directional current fault of the sensed currents, a differential current fault of the sensed first and third currents or the sensed second and fourth currents, and a residual current fault of the sensed first and second currents or the sensed third and fourth currents, and to responsively output the commands. The first, fifth and third conductors are electrically connected in series with two of the circuit interrupters, and the second, sixth and fourth conductors are electrically connected in series with the other circuit interrupters.

Abstract: An electrical switching apparatus includes separable contacts; an operating mechanism structured to open and close the separable contacts; and a trip mechanism cooperating with the operating mechanism to trip open the separable contacts. The trip mechanism includes an input structured to receive a remote signal to remotely enable an arc reduction maintenance mode, a first circuit structured to enable the arc reduction maintenance mode in response to the received remote signal, and a second circuit structured to provide an electrical signal remote from the trip mechanism in order to remotely indicate that the arc reduction maintenance mode is remotely enabled.

Abstract: A totally insulated switched mode power supply for producing a supply voltage for an electrical device, wherein the switched mode power supply includes a first and a second electrical conductor, of which one electrical conductor is for connection to a phase conductor and the other electrical conductor is for connection to a neutral conductor of a grounded AC or three-phase power supply system, and includes Y capacitors for asymmetrical interference suppression of the switched mode power supply such that measures are provided for reducing fault currents or leakage currents.

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: According to one aspect of the invention, a plug-in module is provided for installing in a power distribution assembly. In one embodiment, the plug-in module may include an overcurrent protection device, a power cable, which may include a first end coupled to the overcurrent protection device, and a second end coupled to the first end, one or more receptacle outlets attached to the second end and electrical contacts coupled to the overcurrent protection device and configured to couple the plug-in module to a plurality of stationary electrical conductors of the power distribution assembly.

Abstract: The disclosure relates to a process of configuring a standalone self-supplied numeric controlled relay for providing phase and earth over current protection to electrical systems by accurate current measurement. The arrangement for current measurement with control algorithms is provided for power control by providing amplified and conditioned current for optimization between the current to power an electronic circuit and the fidelity of a measured current waveform so that they both are at the acceptable levels at the same time. This disclosure describes the current sensing and associated algorithm for power control in a truly self-powered relay.

Abstract: A switchgear includes a switching device, which is driven by a propellant chemical charge or fast acting switch. The switchgear includes a current or fault current detection unit, and an optical sensor unit for light arc or fault light arc detection, without the need of having an auxiliary voltage applied. In order to reduce the closing time of an earthing switch, the electrical circuit of an inductive current detection unit is electrically connected in series with a light sensing switching path, and a current signal directly ignites the propellant chemical charge or fast acting switch by using a limited electronic device.

Abstract: Circuits integrated or integrable with a photovoltaic panel to provide built-in functionality to the photovoltaic panel including safety features such as arc detection and elimination, ground fault detection and elimination, reverse current protection, monitoring of the performance of the photovoltaic panel, transmission of the monitored parameters and theft prevention of the photovoltaic panel. The circuits may avoid power conversion, for instance DC/DC power conversion, may avoid performing maximum power tracking to include a minimum number of components and thereby increase overall reliability.

Abstract: A method of operating an integrated circuit breaker module for a solar power system includes following steps: a first circuit breaker is used to provide a short-circuit trip protection; a second circuit breaker is used to provide a grounding-fault trip protection; the first circuit breaker and the second circuit breaker are integrated to form a modular structure and a linking unit is connected between the first circuit breaker and the second circuit breaker to provide a linking trip operation; and the second circuit breaker trips and the first circuit breaker is simultaneously tripped via the linking unit when a grounding fault occurs. Accordingly, a grounding fault protection, an over-current fault protection, and a short-circuit fault protection are implemented.

Abstract: The invention relates to an arrangement (10) for ground fault monitoring of an AC circuit between, on one hand, a neutral conductor (N?) of the AC circuit and, on the other hand, a protective ground wire (PE) or a ground wire with a series connection of ohmic resistors (R1, R2, R3), which has a first terminal (101) for the neutral conductor (N?) and a second terminal (102) for the protective ground wire (PE) or ground wire, wherein the arrangement includes at least one means for detecting a break of one of the resistors (R1, R2, R3) of the series connection.

Abstract: In general, in one aspect, the disclosure describes a digital network to telephone interface device having a controller capable of detecting foreign voltage faults without interrupting telephone service. Upon detection of a foreign voltage fault the controller can deactivate the telephone service and initiate a test sequence to confirm the foreign voltage fault. If the fault is confirmed the telephone service remains deactivated and an operator of the digital network is notified. The device will improve the quality of service and save the cost of sending some one to investigate the fault. The operator can take proactive action once the device provides fault analysis and information remotely.

Abstract: A GFCI device with circuit condition detection function includes a leakage current detection circuit, a disconnect mechanism, a reset mechanism, a circuit condition detection and control circuit, and a selection switch. The disconnect mechanism includes a first SCR controlled by the leakage current detection circuit. The circuit condition detection and control circuit includes a first control circuit and a second control circuit. When the first control circuit is connected to an anode of the first SCR by the selection switch, it provides an intermittent simulated leakage current to the leakage current detection circuit, and the leakage current detection circuit provides a trigger signal for a control gate of the first SCR, so that the first control circuit generates an intermittent simulated leakage current. When the leakage current detection circuit is not operational to generate the trigger signal, the first control circuit generates a control signal to disable the GFCI device.

Abstract: It is judged whether the abnormal current is due to the electric leakage or not by a detection step detecting the abnormal current by the leakage current detection board and comparing a threshold value of predetermined items stored in a storing unit and actual values corresponding to the items at the time of when a compressor is stopped by detecting the abnormal current in the detection step. Specifically, the abnormal current is recognized as the electric leakage to be displayed on a display unit when at least one of the operating time at the time of detecting the abnormal current, the inner pressure of a motor, and a discharge pipe temperature is lower than the corresponding threshold value.

Abstract: The present invention is directed to a protective wiring device including a fault detection circuit configured to provide a fault detection signal in response to a fault condition or a simulated fault condition. A second circuit is coupled to at least one user-accessible button and is configured to conduct a second signal in response to a user actuation of the at least one user-accessible button if the plurality of line terminals are coupled to a source of AC power, the second signal not simulating the fault condition. An automatic test circuit is configured to periodically determine whether the fault detection circuit is operative and provide an electronics test failure signal if the fault detection circuit fails to provide the fault detection signal in response to the periodically effected simulated fault condition.

Abstract: A device (10) is disclosed that is suitable for testing an earth connection (30) that is isolated from a mains electricity supply. The device (10) comprises means (14, 40) for electrically connecting the device (10) to the earth connection (30), and means (16, 32) for electrically connecting the device (10) to an electrically conductive item (20) having a capacitance relative to an adjacent surface of the earth that is within a pre-determined range of capacitances. Furthermore, the device (10) includes means for generating an AC signal and delivering the AC signal to the electrically conductive item, and means for determining whether the resistance between the earth connection (30) and earth reference potential is less than a maximum earth resistance value. This determination is achieved by comparing the frequency of the generated AC signal with a pre-determined range of frequencies.

Abstract: A leakage current masking device for use with a circuit includes at least one inductive load device coupled to the circuit and configured to supply an inductive load to the circuit, and a processor communicatively coupled to the inductive load device. The processor is configured to receive a signal representative of a current through the circuit, calculate a capacitive leakage current component of the current, and cause the inductive load device to adjust the inductive load supplied to the circuit to reduce the capacitive leakage current component.

Abstract: The leakage detection protection circuit comprises power input and output ends, an induction coil, a self-excitation coil, a control chip, a controlled silicon rectifier, a commutation diode, a resistor, a current limiting resistor, a filter capacitor, a tripping coil, a pair of main circuit switches linked with a reset button, a test button, and first and second test switches. When the reset button is in a tripped state, the first test switch is open and the second test switch is closed. Additionally, when the reset button is pressed down, the first test switch changes from open to closed, the second test switch remains closed, and the neutral wire of the power input end is connected to the output end of the live wire of the power input end to enable generation of an analog leakage current. Finally, when the reset button is reset, the first and second test switches are both open.

Abstract: A power system for a vehicle includes at least two battery packs spaced away from each other. A first battery pack includes a plurality of battery cells and a switching element electrically connected with the battery cells. A second battery pack includes a resistor electrically connected in series with the switching element, and sense circuitry configured to detect voltage across the resistor indicative of leakage current associated with the first battery pack.

Abstract: A device for controlling and regulating a DC voltage converter. The device may have one or more power output stages and a control unit with a signal ground line. The one or more power output stages and the control line have a mutual ground potential. A switch for electrically disconnecting the signal ground line is provided. The switch is opened, when the DC voltage converter is active and the switch is closed, when the DC voltage converter is inactive.

Abstract: An electrical power converter for converting power from a bipolar DC source to supply an AC load is disclosed. For one such embodiment the bipolar DC source is a photovoltaic array and the AC power is sourced into an electric power grid. The bipolar photovoltaic array has positive and negative voltage potentials with respect to earth ground. The converter is a utility interactive inverter which does not require an isolation transformer at the electric power grid interface. Embodiments of the invention include methods of detecting and interrupting DC ground faults in the photovoltaic array.

Abstract: The invention relates to a GFCI that trips and provides indication at the end of its life. It comprises a leakage signal detection circuit (LSDC) and a failure alarm for providing indication in case of failure. The LSDC includes a leakage signal amplification circuit (LSAC) which amplifies the signal from test and neutral toroidal coils and controls a mechanical tripping mechanism through a silicon control unit and an igniter. The mechanical tripping mechanism is controlled by the LSDC through the silicon control unit by a forcible tripping coil connected thereto. This LSDC is powered by a power unit. Additionally, a failure alarm circuit which triggers and supplies visual indication through an optical display element in the event of failure is connected to the power unit of the LSDC. This alarm circuit also includes a forcible tripping coil to control the mechanical tripping mechanism at the end of the device life.

Abstract: The present invention provides a circuit interrupting device which comprises a leakage current detection and protection circuit containing a simulated leakage current generation circuit which is capable of automatically generating a simulated leakage current when the circuit interrupting device is properly wired and in a tripped state to automatically test the functions of the key components of the circuit interrupting device. The simulated leakage current generation circuit comprises a normally closed switch and a normally open switch. The leakage current detection and protection circuit further comprises a normal status indicator light and a power output indicator light to indicate whether the circuit interrupting device is working properly and/or reverse wired. The circuit interrupting device further comprises a reset switch, a pair of discharged metal pieces, and four pairs of circuit interrupting contacts.

Abstract: A method generates an error signal indicating the location of a ground fault in a line between two line ends. A voltage and a current are measured at both ends of the line, establishing measured values, and the location of the ground fault is determined when or after a ground fault is detected. Accordingly, harmonic indicator variables are established and used for determining the location of the ground fault.

Abstract: An electric safety circuit for use with an electric receptacle includes a relay and contacts in which power from a mains is supplied through the contacts to the receptacle only when the contacts are closed; a transistor for controlling the relay to open or close the contacts; an enabling device for supplying an enabling signal to the transistor to close the contacts when a plug of an electrically connected device is inserted into the receptacle, the electrically connected device is turned on, and there is no electrical contact by a person with the power supplied to the electrically connected device; and a disabling device for supplying a disabling signal to the transistor to open the contacts when there is electrical contact by a person with the power supplied to the electrically connected device.

Abstract: The present invention is directed to an electrical wiring device that includes a frameless shutter assembly that is disposed in the front cover portion or in the at least one separator member between the plurality of receptacle openings and the plurality of receptacle terminals. The at least one frameless shutter assembly comprises a first shutter member and a second shutter member configured to move from a closed position to an open position when the hot and neutral blades of a plug blade set are simultaneously inserted into the receptacle openings to engage a set of receptacle terminals and remain closed otherwise. The front cover member and/or the at least one separator includes a first stop member disposed proximate the first shutter member and a second stop member being disposed proximate the second shutter member.

Abstract: A vehicle is provided having an electric machine and a speed detector coupled to the electric machine. A controller is coupled to the speed detector. The controller may analyze the integrity of communication between the speed detector and the controller based on a frequency signal provided with the speed detector.

Abstract: A power control apparatus comprises a transducer having an output (12,13) which is connected to a remotely activated device (25) mounted in a mains consumer unit (14). When a predefined parameter is detected, the device (25) is activated to connect a load (29) between the switched live output (18) of a residual current device RCD (15) and the neutral input (17) thereof, thereby creating an imbalanced current flow on the live and neutral output terminals (18,19) of the RCD (15) which causes contacts (20,21) inside the RCD (15) to disconnect the supply to an appliance circuit (22).

Abstract: The invention relates to a remotely-controllable circuit breaker, including a first circuit breaking unit, remote control unit, and housing. The first circuit breaking unit and the remote control unit are disposed in the housing; the first circuit breaking unit operates to switch on or off loads and electric lines; the remote control unit operates to control the interruption of the remotely-controllable circuit breaker via a remote control signal; and the housing is made of insulating and flame-retardant materials.

Abstract: The present invention discloses a short-circuit detection circuit and a short-circuit detection method. The short-circuit detection circuit detects whether an output node is short-circuited to a first predetermined level. A first switch circuit which is controlled by a control signal is coupled between the output node and a second predetermined level. The short-circuit detection circuit includes: a determination circuit, which is coupled between the output node and the second predetermined level, wherein when the determination circuit is enabled, it generates a determination signal according to whether the output node is short-circuited to the first predetermined level; and a second switch circuit, which generates a short-circuit detection signal according to the determination signal.

Abstract: This invention relates to a residual current device which is able to safely and reliably operate when a line voltage is present (voltage dependent mode) and when the line voltage is not present or falls below a predetermined threshold level (voltage independent mode). The present invention is implemented as a residual current device having a trip mechanism for isolating an electric supply to an electrical installation upon detection of a predetermined current imbalance between the line and neutral conductors of said electric supply. The present invention comprises a current transformer having a secondary winding responsive to any current imbalance on said electrical installation, and a circuit protection winding being connectable to a processing means.

Abstract: The present invention is directed to an electrical wiring device that includes at least one user accessible input mechanism and a test assembly configured to initiate a self-test in response to stimulus signal. The self test determines whether a sensor, a fault detection circuit or a circuit interrupter assembly are in an operational mode or are in a failure mode, the reset stimulus being provided in the operational mode and a reset lockout stimulus being provided in the failure mode. The device also including a reset lockout mechanism coupled to the circuit interrupter assembly and the test assembly. The reset lockout mechanism is configured to disable the reset stimulus in response to the reset lockout stimulus if any one of the at least one sensor, at least one fault detection circuit, or circuit interrupter assembly is determined to be in the failure mode after a predetermined time elapses.

Abstract: An ultra-low sensitivity ground fault circuit interrupter (GFCI) device and a method for manufacturing the device is disclosed. The GFCI device detects an unbalanced current between line and return conductors that results from an unintended path to ground. The GFCI device disconnects the current source when a leakage current is detected. The GFCI device includes a current transformer that has its core wrapped with the line and return conductors. The line and return conductors are secured around the core in a fixed position. During manufacture of the GFCI device an amplifier of the GFCI can be adjusted so that the GFCI device disconnects the current source when a leakage current exceeds a desired level.

Abstract: A battery charger for charging an electrically-driven vehicle by connecting the electrically-driven vehicle with an external power source, the battery charger includes an earth leakage detector operable to detect earth leakage of the battery charger; an earth leakage circuit breaker operable to switch energization from the external power source; an earth leakage confirmation relay capable of forcibly causing earth leakage in a downstream circuit of the earth leakage detector; a resistor unit connected in series with the earth leakage confirmation relay and capable of being set to any one of a plurality of leakage current values; and a controller operable to switch the earth leakage circuit breaker based on a detection result of the earth leakage detector while forcibly causing earth leakage in the downstream circuit.

Abstract: Short protection control circuits and related control methods are disclosed. A disclosed short protection control circuit is adapted for controlling a short protection mechanism providing short protection to several LED chains. The disclosed short protection control circuit has a detection circuit, a first logic circuit and a timer. Coupled to the LED chains, the detection circuit asserts an indication signal when one of the node voltages of the LED chains is lower than an under-current reference. When the indication signal is enabled, the first logic circuit starts blocking the short protection mechanism. The timer times to provide a result when the short protection mechanism is blocked. When the result indicates that the short protection mechanism has been blocked for at least a predetermined time period, the first logic circuit resumes the short protection mechanism.