Abstract: A time delay fault device includes an integrated circuit (IC) having an electronic circuit having a fault indicator signal output and a time delay circuit having an input connected to the fault indicator signal output and an output to provide a delayed fault indicator signal output, the time delay circuit being responsive to an external voltage from a resistor capacitor network coupled to the delayed fault indicator signal output to set the time delay of the delayed fault indicator signal.

Abstract: A system for evaluating at least one tripping stimulus for a ground-fault circuit interrupter includes: a sensing circuit configured to measure a leakage current from a voltage line to ground, wherein the sensing circuit is capable of generating a leakage signal including a voltage representative of the leakage current; and an evaluating circuit configured to evaluate the leakage signal to generate an indication signal, wherein the indication signal includes information corresponding to the at least one tripping stimulus. The sensing circuit may include a circuit substantially similar to at least a portion of a ground-fault circuit interrupter, and the evaluating circuit may include a peak hold circuit. The system may further include an indicator circuit for receiving the indication signal and displaying a status of the tripping conditions.

Abstract: A device for detecting a fault current in an electronic apparatus has a first and at least one second electric conductor, the first electric conductor carrying a first electric potential and the at least one second electric conductor carrying a second electric potential. The device is characterized by the fact that an electric sensing conductor having a fixed electric rest potential whose value lies between the first and the at least second electric potential is situated between the electric conductors.

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: A circuit interrupter with end-of-life protection has four components: 1) a control circuit to activate an electromagnetic unit upon detecting a predetermined condition; 2) a fuse coupled between the control circuit and the power supply; 3) an end life sensing circuit coupled to the control circuit; and 4) an end life indicating circuit coupled to the end life sensing circuit and the power supply. The end life sensing circuit includes a light emitting device and a light sensitive device controlled by the light emitting device. The end life indicating circuit includes a visual indicator to indicate that the circuit interrupter reaches the end of its life. Another circuit interrupter with end-of-life protection has three components: 1) a control circuit to activate an electromagnetic unit upon detecting a predetermined condition; 2) a fuse coupled between the control circuit and the power supply; and 3) an end life sensing and indicating circuit coupled to the control circuit.

Abstract: This invention relates to an earth leakage protection device with built in time alert feature. In one embodiment, the earth leakage protection device includes a time alert module provided with a microprocessor system with an alert trigger timer and annunciators. The said earth leakage protection device provides an audible and/or visual annunciation to remind the user to perform integrity test on the earth leakage protection device at a preset time interval. If the earth leakage protection device fails the integrity test, the user detects that the earth leakage protection device needs to be replaced. If the earth leakage device passes the integrity test, the alert trigger timer is reset for another preset time interval. The time alert module of the earth leakage protection device can be further provided with a message display panel.

Abstract: Various systems, methods and apparatus are described for detecting an excessive or faulty ground current in a conductive wire or electronic device. A ground current detector is coupled to a known earth ground to determine whether other ground lines are carrying excessive, faulty and/or leaking currents. If these types of unsafe conditions are detected, then a user can take appropriate action to locate and correct these problems.

Abstract: A dimming system and method of operating the same are provided. The dimming system includes a first terminal configured to operatively connect to a first conductive line, a second terminal configured to operatively connect to a second conductive line, and a third terminal configured to operatively connect to a third conductive line. The first conductive line is configured to connect to a load, the second conductive line is configured to supply an alternating current, and the third conductive line is configured to connect to a current path. The dimming system further includes a controller operatively connected to at least one of the first, second and third terminals for controlling operation of the dimming system. The first and second terminals are configured for electrically connecting to a primary power supply and the first and third terminals are configured for electrically connecting to a secondary power supply.

Abstract: Systems and methods are disclosed for detecting a faulty ground strap connection for a machine hosting a high voltage system. In one embodiment, a fault detection and compensation system includes a ground strap, a DC power supply electrically referenced to a machine frame, a leakage detection switch connected to the machine frame, a current source controlled by the leakage detection switch, and a voltage measuring device that measures an offset voltage. The fault detection and compensation system further includes a leakage detection and compensation controller that compensates for the unbalanced fault condition by controlling the leakage detection switch and the current source, and determines whether the ground strap is properly connected to the machine frame.

Abstract: Computer systems and techniques for predicting a cable failure in a network system begin by receiving a remote alarm indicator followed by a remote alarm indicator clear as a transmission alarm indicator of an intermittent short duration failure on the transmission path of a circuit. If the transmission alarm indicator is of a duration less than or equal to a preset threshold D it is considered an acceptable short hit transmission alarm. When at least N acceptable transmission alarms have been received and the time stamps of the last N acceptable transmission alarms have been recorded, then a determination is made as to whether N acceptable transmission alarms have been received within a preset time period. A moving window time period is calculated as the difference between the time stamp of the present acceptable transmission alarm K and the time stamp of the [(K?N)+1] acceptable transmission alarm. If the difference is less than or equal to T, a cable error signature is indicated.

Abstract: A self testing fault detector having a line side and a load side and a conductive path there between, said apparatus is provided. The self testing fault detector includes a controller, adapted to perform periodic status tests on a protection circuit of the self testing fault detector without interrupting power to the load.

Abstract: A load status indicator is disclosed for determining whether power is available to, and current is flowing through, a load. A first visual status indicator may light up when power is available to the load but current is not flowing through the load. A second visual status indicator may light up when power is available to the load and current is flowing through the load. A bi-color light-emitting diode may comprise the first and second visual status indicators. Transistors may be used to permit or prevent current from flowing through the visual status indicators. In some embodiments, a reed switch or a hall-effect sensor may be used to determine whether current is flowing through the load.

Abstract: A penetration screen is disclosed which comprises a substantially planar substrate with, at least, one electrical circuit disposed thereon. The electrical circuit is configured such that, at least, one section of the circuit is electrically isolatable from the remainder of the circuit without causing a fault condition in said remainder of the circuit.

Abstract: The disclosed detection circuit for a seatbelt apparatus may include an attachment detection switch, first and second resistance elements, and an LED. The resistance value of the first resistance element may be set to a value which allows a current smaller than the maximum current value which cannot turn the LED on to flow through the LED when the attachment detection switch is in an OFF state. The resistance values of the first and second resistance elements can be set to values which allow a current larger than the minimum current value which can turn the LED on to flow through the LED when the attachment detection switch is in an ON state. A monitoring circuit may determine whether or not the tongue on the seat is attached to the buckle.

Abstract: A circuit breaker includes a first lug and second and third acoustic lugs electrically connected to a power circuit. Separable contacts are electrically connected in series between the first lug and the second acoustic lug. An operating mechanism opens and closes the separable contacts. A first acoustic sensor is coupled to the second acoustic lug and senses a first acoustic signal from the second acoustic lug. A second acoustic sensor is coupled to the third acoustic lug and senses a second acoustic signal from the third acoustic lug. The first and second acoustic signals are operatively associated with a power circuit fault. A current sensor senses a current flowing between the first and second lugs. A circuit inputs the sensed acoustic signals and the sensed current and detects and distinguishes a parallel arc fault or a series arc fault from the sensed acoustic signals and the sensed current.

Abstract: A battery pack features a shock-absorbing and sealed construction and an electronic control module that provides automatic recovery circuitry in the event of a short circuit in the load whereby the power is terminated and then restarted at a lower level so that removal of the short circuit may be detected. Full power is restored to the load when the short circuit is removed. In addition, the electronic control module of the battery pack uses the battery pack load, such as a cap lamp, to provide an indication of a low battery charge level. The electronic control module also provides a soft-start feature where the power provided to the bulb is ramped up to avoid current in-rush to the bulb during startup.

Abstract: Computer systems and techniques for predicting a cable failure in a network system begin by receiving a remote alarm indicator followed by a remote alarm indicator clear as a transmission alarm indicator of an intermittent short duration failure on the transmission path of a circuit. If the transmission alarm indicator is of a duration less than or equal to a preset threshold D it is considered an acceptable short hit transmission alarm. When at least N acceptable transmission alarms have been received and the time stamps of the last N acceptable transmission alarms have been recorded, then a determination is made as to whether N acceptable transmission alarms have been received within a preset time period. A moving window time period is calculated as the difference between the time stamp of the present acceptable transmission alarm K and the time stamp of the [(K?N)+1] acceptable transmission alarm. If the difference is less than or equal to T, a cable error signature is indicated.

Abstract: Provided is a system, a tool and a method for communicating with a faulted circuit indicator (FCI), the faulted circuit indicator including a detection circuit for monitoring an electrical conductor of a power system. The system includes a remote display mounted in a wall of an enclosure and visible from outside of the enclosure and a first light emitting diode associated with the remote display. The first light emitting diode generates an optical FCI status signal in response to an occurrence of a fault in the electrical conductor. The system also includes a first microcontroller operatively coupled to the remote display and the detection circuit, and a handheld user command tool adapted to optically couple with the remote display. The handheld user command tool is also adapted to generate an optical serial communication. The optical serial communication provides data and commands for operation of the faulted circuit indicator.

Abstract: A controller suitable for identifying an abnormal operational condition in a bathing system is provided. The controller includes a memory unit adapted for storing measurements indicative of electrical currents drawn by the bathing system under normal operating conditions, each measurement being indicative of the electrical current being drawn by a respective bathing unit component in the bathing system. The controller also includes a processing unit for modifying the measurements stored in the memory unit and for detecting an abnormal operational condition associated with the bathing system at least in part on the basis of measurements stored on the memory unit. In specific implementations, sensing circuitry adapted for obtaining measurements associated to components, such as relays and fuses, is provided.

Abstract: A load status indicator is disclosed wherein a green light-emitting diode of a bi-color light-emitting diode lights up when power is available to but not being used by a monitored device, whereas a red light-emitting diode of the bi-color light-emitting diode lights up when the monitored device is drawing current. The load status indicator utilizes a coil in series with the monitored device, a reed switch controlled by the coil, and field-effect transistors to control which light-emitting diode lights up depending on whether power is available and whether the monitored device is drawing current.

Abstract: Method and system for managing cabling rooms that include a plurality of communication panels, which are arranged closely to one another. Each cabling room has a plurality of patch panels, structurally connected to form vertical structures. An operator is automatically guided to a communication panel or a plurality of communication panels, in which changes are to be made to modify the connectivity status or to deal with connectivity problems that may arise for any reason. The system automatically indicates to an operator optimal ports that are available and optimal patch cords for connecting them, based on distances between ports and on the electrical characteristics of the electrical signals that it is intended to pass between the ports.

Abstract: A system for evaluating at least one tripping stimulus for a ground-fault circuit interrupter includes: a sensing circuit configured to measure a leakage current from a voltage line to ground, wherein the sensing circuit is capable of generating a leakage signal including a voltage representative of the leakage current; and an evaluating circuit configured to evaluate the leakage signal to generate an indication signal, wherein the indication signal includes information corresponding to the at least one tripping stimulus. The sensing circuit may include a circuit substantially similar to at least a portion of a ground-fault circuit interrupter, and the evaluating circuit may include a peak hold circuit. The system may further include an indicator circuit for receiving the indication signal and displaying a status of the tripping conditions.

Abstract: A warning device that turns on a warning light and or a warning sound to indicate when a manhole cover or a service box cover or a metal pole for lights, traffic lights, transformers or others has become dangerously electrically charged. The invention is attached to the frame of a manhole cover, or a service box cover or a metal pole. The light and sound warns people to stay off the covers and their surrounding areas, and the surrounding areas of the metal poles.

Abstract: The present invention relates to a circuit arrangement and a method for load diagnosis of a switch having a first and a second load connecting terminal. A first and a second current source arrangement are provided, which can in each case be connected to one of the load connecting terminals of the switch and which supply, depending on potential conditions at the said load connecting terminals, currents in a first and second current direction or oppositely to the said first and second current direction to the load connecting terminals. Furthermore, an evaluation circuit is provided, which evaluates the currents flowing to the first and second load connecting terminals and provides a load state signal depending on the said currents.

Abstract: A wiring error detection circuit for providing the status of the wiring of an AC outlet and the status of the AC outlet's ground connection.

Abstract: A connector assembly for a wriststrap jack is provided wherein the jack may be easily replaced in accordance with the invention.

Abstract: An evaluator (210) having an input (207) for receiving a signal indicative of a channel current sensed via a sensor in a mutlichannel current sharing system, and circuitry (313, 319) coupled to the input (207) and responsive to the signal for indicating an unreliable sensing for the sensor when a low current condition occurs for a time period exceeding the switching time period of the channel current. Further, the apparatus can include an additional input (207) and circuitry (313, 319) for evaluating an additional sensor sensing an additional channel current. The low current condition is characterized by thresholds corresponding to the peak level and a valley level of the channel current over a switching time period.

Abstract: An automatic testing system. A sampling and converting device obtains a plurality of electronic parameters from a tested device and transforms them into a plurality of digital signals. A microprocessor receives the digital signals and performs various short-circuit tests, over-current tests and over-voltage tests in a specific sequence.

Abstract: An electrical hazard detection system is used to detect energized ground terminals on electric receptacles. This condition may not be detectable by traditional circuit testers when hot and neutral wires have been switched and ground terminals have been electrically connected to the neutral wires. The user's body is used to provide a high-impedance path to true ground thereby creating an electric current from an energized ground terminal, activating a transistor, and illuminating an associated indicator.

Abstract: A short circuit detector for a fieldbus network which includes power/data wires that are typically positive and negative, respectively, and a shield conductor connected to a ground includes first and second high-impedance semiconductor circuits coupled between each of the leads and the shield conductors. Both circuits may either have a dedicated alarm indicator which indicates the presence of a short circuit between that conductor and the shield and/or may be coupled together to an alarm circuit which activates an alarm whenever a short circuit exists between either of the power/data leads and the shield conductor. The alarm circuit may have a ground which is isolated from the shield ground and may thus employ an isolation device such as an opto-isolator.

Abstract: A circuit breaker with a thermal/magnetic trip device incorporates a monitor that senses the temperature of the bimetal and the amplitude of the load current to distinguish between a thermal and a magnetic trip. If the temperature of the bimetal is above a selected value when the circuit breaker trips, a “THERMAL” trip light emitting diode (LED) is energized, while a high load current at the time of a trip lights a “MAG” trip LED. The monitor also energizes an “ARC” LED in response to an arc fault signal from an AFCI at the time of trip, or a “GRD” LED in response to a ground fault trip. If a trip sensor, which monitors load voltage does not detect opening of the circuit breaker contacts when an arc fault or ground fault signal is generated, the corresponding LED is flashed to indicate the failure to trip. The monitor also has a “SURGE” LED to indicate a voltage surge in the protected distribution system as detected by a surge detector built into the circuit breaker.

Abstract: A warning device including a status and function indicator circuit for indicating the status and function of the warning device. In a visual warning device such as a strobe light, the status and function indicator circuit includes a status output device such as an LED. The LED and associated circuitry are configured to indicate both proper operation of the visual warning device and, in the event of a device failure, will indicate whether the fault lies with circuitry for the visual warning device or simply with a warning output device.

Abstract: A device for de-energizing an energized branch electrical circuit is described, as well as related processes. The device includes a circuit breaker, which itself includes a breaker switch, an input terminal for receiving current, and an output terminal for directing current out of the breaker. A plug is also incorporated into the device, so that the device can be inserted into an electrical receptacle in the branch electric circuit. One or more power indicators, such as an LED light or voltmeter, are also incorporated into the device. When the device is plugged into a receptacle of the branch circuit, the breaker switch can then be turned on, resulting in a short-circuit, which de-energizes the branch electrical circuit. The device may also include a holder, which is capable of retaining at least one electrical adapter.

Abstract: A method and apparatus for testing for latent faults in the isolation devices of a system including redundant power supplies which supply power to one or more system units. A system controller is operable to perform a test cycle to perform the fault checks, which may including checks for short circuits and/or open circuits. The checks may be performed within a test cycle in which each of the isolation devices in the system is tested. The test cycle may be performed at regular intervals, the interval between each cycle being determinable by user input. In the event that a fault in one of the isolation devices is detected, the system controller may be operable to report the fault to an alarm system.

Abstract: Detecting a signal disruption of an AC-signal by a DC-current in a powered networking system includes receiving an AC-signal from the networking system; analyzing the AC-signal based on a predetermined characteristic of the AC-signal and generating an analysis output; then comparing the analysis output with a predetermined reference source wherein the comparing detects the AC-signal disruption in the powered networking system.

Abstract: A method and apparatus for monitoring grounding of personnel and equipment in electrostatic discharge (ESD) sensitive areas. The device generates a low voltage alternating current control signal (60) which is applied to personnel (50) and equipment (350) being monitored. The device further includes signal conditioning (66) and detection means (70) to distinguish static charges from the control signal and transmit an alarm (72) upon detection of such static charge. The method encompasses the use of an alternating current control signal to detect static charge.

Abstract: A device for indicating whether a conductive element has an electrical resistance equal to or less than a predetermined value or whether the conductive element is reliably connected to earth reference potential by a resistance equal to or less than a predetermined value. The device includes a clamp device for connecting the device to the conductive element and which incorporates a battery powered monitoring unit. The monitoring unit includes a current-to-voltage converter with a voltage output that is inversely proportional to the resistance of the conductive element, a comparator which compares at predetermined intervals voltage output to a pre-set reference and determines whether the measured resistance is equal or less than the predetermined value, and a signaling device which is actuated to provide an indication as to whether the measured resistance is equal to or less than the predetermined value.

Abstract: A data sample and transmission module for a power distribution system having a microprocessor, a locator device, and a network interface is provided. The microprocessor samples one or more first signals indicative of a condition of power in the power distribution system. The locator device is changeable between a first state and a second state. The network interface can place the microprocessor in communication with a network so that the microprocessor samples the first signals based in part upon a synchronization signal receivable from the network and so that the locator device changes from the first state to the second state in response to a command receivable from the data network.

Abstract: A transducer calibration apparatus and method for transforming both previously established transducer parameters for a transducer calibrated to a first target object material and measured transducer parameters for the transducer monitoring a second different target object material into a calibration parameter and transforming the output of the transducer and thus, the use of the transducer, from the first target object material used to calibrate the transducer to the second different target object material being subsequently monitored by the transducer by linearizing the output of the transducer into gap values as a function of the calculated calibration parameter and then, generating alarms based on the linearized output of the transducer exceeding established limits and using the alarms to automatically shut down a machine being monitored by the transducer and/or automatically annunciate machine problems to personnel.

Abstract: An electrical circuit tester for allowing a user to efficiently test electrical fixtures and switches. The electrical circuit tester includes a housing that has a plurality of prongs that extend from the housing. The prongs are adapted for engaging an electrical outlet of a building. A plurality of lights is coupled to the housing. The lights are lit in a pattern indicating a state of the electrical outlet. A speaker is coupled to the housing. The speaker is for creating an audible tone when the prongs engage the electrical outlet.

Abstract: The directional element, following enablement under selected input current conditions, calculates a zero sequence impedance, in response to values of zero sequence voltage and zero sequence current. The current value is selected between two possible values, one being the value from an associated current transformer, the other being the sum of the currents IA+IB+IC. The calculated zero sequence impedance is then compared against sensitive selected threshold values, established particularly for ungrounded systems. A forward fault indication is provided when the calculated zero sequence impedance is above a first established sensitive threshold value, and a reverse fault indication is provided when the calculated zero sequence impedance is below a second established sensitive threshold value.

Abstract: Safety system for a manufacturing machine provided with at least one tool which can injure the operator, comprising a pair of gloves to be worn by the operator and provided with an outer surface of dielectric material and an electrically conductive inner surface; an alarm signal generator connected to said conductive inner surface; a processor unit connected to the metal machine members and to said at least one tool via a safety circuit arranged to sense said alarm signal when the operator cuts one of said gloves on coming into contact with one of the mechanical members of the machine, said processor unit being provided with means for interrupting machine operation on sensing said alarm signal, in which said alarm signal is an alternating current signal the intensity of which is established by said processor unit on the basis at least of the physical characteristics of the operator as measured by a suitable circuit for determining at least these characteristics.

Abstract: A ground fault circuit interrupter (GFCI) with built in intelligence is described that includes circuitry to automatically indicate a device miswiring condition. When a GFCI is wired with its AC and LOAD terminals reversed, downstream devices are still protected in the event of a ground fault but the duplex receptacle on the GFCI itself is not. The invention incorporates miswiring sense circuitry that automatically triggers the generation of visual and audible alarms in the event a miswiring condition is sensed. The invention employs an alarm inhibiting technique that incorporates sense circuitry connected to the AC terminals on one side of the internal GFCI switches or relays and alarm generation circuitry connected to the LOAD terminals on the opposite side.

Abstract: A supervisable multi-processor communication system includes circuitry and executable instructions for evaluating the communication capability of a plurality of branches in the system. Branches which exhibit a non-communicating condition, such as an open circuit can be identified. By conducting communications with electrical units on identified branches, the location of an open circuit, relative to one of the electrical units can be established.

Abstract: A circuit breaker which displays electronically state of the circuit breaker and the cause of the disconnection which enables users to determine whether to reconnect a conductor which connects a source and a load in power distribution system. An arc display part is coupled to an arc fault detector, a ground display part is coupled to a ground fault detector and an overload display part is coupled to an overload detector. If arc fault occurs, the arc fault detector generates a trip signal and the trip signal is provided to the arc display part. As the trip signal from the arc fault detector is not provided to the ground display part and the overload display part, users can determine that arc fault has occurred by the lighting of the arc display part.

Abstract: The present invention relates to a method for location of a fault which has occurred on one of a plurality of lines in a power distribution network where the location is performed with the measured values of the common supply voltage of the plurality of lines and the currents of the plurality of lines after the occurrence of a fault; calculating the equivalent positive-sequence impedance Z1kf and zero-sequence impedance ZZ0kf of the network in a pre-fault steady state for all M nodes based on knowledge of the configuration and topology of the network, and obtaining, via a superordinate protection system, which of plurality of lines has become faulty and which type of fault has occurred.

Abstract: An apparatus for determining a failure of wheel speed sensors, which is capable of properly determining whether or not a wheel speed detection system including the wheel speed sensors has failed, if at least a wheel speed detected by the wheel speed sensors indicates a stopped state of a corresponding wheel. An engine rotational speed is detected, and an input-output rotational speed ratio of a torque converter of an automatic transmission mounted in the vehicle is calculated. A shift range of the automatic transmission is detected. Whether or not the vehicle is traveling is determined based on the engine rotational speed and the input-output rotational speed ratio when the automatic transmission is in a traveling range. It is determined that the wheel speed detection system including the wheel speed sensors has failed, if it is determined that the vehicle is traveling, and at the same time, at least one of wheel speed sensors indicates a stopped state of a corresponding one of the wheels.

Abstract: A trip unit, such as one comprising a current sensor generating a current signal indicative of current in a power circuit, an analog to digital converter converting said signal into digital form, and a controller monitoring the current signal and sensing whether an over current condition exists and whether a ground fault condition exists. In case of an over-current condition, the controller causes a trip signal to be output resulting in the power circuit being opened. In the case of a ground fault condition, the controller causes an annunciation output signal but does not generate a trip signal in the case of a ground fault condition and therefore does not cause the power circuit to be opened.

Abstract: A current limiting resistor capable of dissipating power greater than about ¼ Watt is incorporated between the output circuitry of an aftermarket electrical system and an output terminal, so that the output circuitry is protected from excessive currents flowing through the output terminal as a consequence of incorrect connections being made to the output terminal. The resistor has a value of approximately forty Ohms, and a power dissipation rating of three Watts. When correct connections are made, the resistor will permit a current flow from the output terminal of approximately ninety milliAmps through a relay winding, which is sufficient to activate the relay. However, in the case of a miswiring, the resistor will limit the current flow through the output circuitry to no more than about 300 milliAmps.

Abstract: In a method for capacitive object recognition in vehicles, two capacitive electrodes are charged with alternating voltage and the presence of an object is detected by the change in the capacitance in the capacitor. The two electrodes are charged sequentially and individually with alternating voltages. The alternating currents that result in the leads of the two electrodes are analyzed jointly.