Abstract: A circuit interrupter is structured to protect a protected circuit. The circuit interrupter includes a ground fault current sensor structured to sense a ground fault current in the protected circuit and a processor including a routine structured to perform a ground fault output self-test. The ground fault output self-test includes to output a trip signal within a predetermined phase angle of a zero-crossing of current flowing through the protected circuit, to stop outputting the trip signal before the zero-crossing, to determine whether the trip signal caused a pulse in the ground fault current, and to determine whether the circuit interrupter passed the ground fault output self-test based on whether the trip signal caused a pulse in the ground fault current.

Abstract: A switch includes: at least one conducting line led through the switch; switching contacts arranged in the at least one conducting line; at least one measurement transformer arranged at the at least one conducting line; an electronic trip unit, a measurement-input of the electronic trip unit being electrically connected to a measurement transformer secondary winding of a measurement transformer; a power supply unit; at least one power transformer arranged at the at least one conducting line, the at least one power transformer including a power transformer secondary winding which is electrically connected to the power supply unit in order to supply the electronic trip unit; a signal generating unit for generating a test signal with at least a first predefined frequency, with an output of the signal generating unit being electrically connected to the power transformer secondary winding; and a self-test unit electrically connected to the measurement transformer secondary winding.

Abstract: A circuit interrupter including a first set of separable contacts, a second set of separable contacts, a first operating mechanism structured to open the first set of separable contacts, a second operating mechanism structured to open and close the second set of separable contacts, and an electronic trip unit including a routine structured to detect a fault condition and a type of the fault condition, to control the second operating mechanism to open the second set of separable contacts in response to detecting a first type of fault condition, and to control the second operating mechanism to close the second set of separable contacts a predetermined amount of time after controlling the second operating mechanism to open the second set of separable contacts.

Abstract: A ground fault circuit interrupter (GFCI) having an automatic self-test feature is configured to disable a trip circuit therein during a self test, yet still allow the trip circuit to respond during the self test to detection of a large ground fault by tripping a main contact switch of the GFCI. The GFCI includes circuitry that overrides the disablement of the trip circuit during a self test in response to detection of a ground fault that exceeds a predetermined threshold. Methods of disabling a trip circuit of a GFCI during a self test while still allowing the trip circuit to respond during the self test to detection of a large ground fault are also provided, as are other aspects.

Abstract: An air conditioning system for motor vehicles includes a temperature door configured to adjust an opening degree of a hot air path, a PTC heater configured to heat an air introduced into the hot air path, and a control unit configured to control an opening position of the temperature door with respect to the hot air path and to secure a minimum opening degree of the hot air path, so that a minimum amount of air is blown toward the PTC heater regardless of the opening position of the temperature door. The control unit is configured to actively adjust the minimum opening degree of the hot air path depending on an on/off condition of the PTC heater.

Abstract: The present invention relates to built-in testing of detectors for the detection of electrical arc faults or transients, where the detector is integrated into or electrically coupled to an electrical power supply system.

Abstract: A circuit interrupter for a power circuit includes separable contacts, an operating mechanism structured to open and close the separable contacts, and a trip circuit cooperating with the operating mechanism to trip open the separable contacts. The trip circuit includes a number of hardware circuits having a processor with a number of routines. The routines provide a number of protective functions structured to detect a number of faults of the power circuit, a number of repetitive test functions for the number of hardware circuits, and a supervisory function cooperating with the number of repetitive test functions. The supervisory function is structured to prevent availability of protection by the number of protective functions from falling below a predetermined threshold as a result of a plurality of intermittent error conditions of the number of hardware circuits.

Abstract: A switching arrangement is disclosed comprising: a control circuit; a latching relay controlled by the control circuit for connecting an AC source to an AC load; and a relief circuit in parallel with the relay and controlled by the control circuit. The relief circuit has two modes of operation: an inactive mode in which the relief circuit is non-conductive and an active mode in which the relief circuit is at least partially conductive. The relief circuit is partially conductive when spending both a time period in a conductive state and a time period in a non-conductive state during a half-cycle of the AC. The control circuit is configured to switch the relief circuit from inactive mode to active mode, and upon switching to active mode, to set the relief circuit as partially conductive for at least two half-cycles, wherein the proportion of time the relief circuit is conductive compared to non-conductive is increased for successive ones of the at least two half-cycles.

Abstract: Physical layer device auto-adjustment based on power over Ethernet (PoE) magnetic heating. In one embodiment, information generated by a PoE module that is indicative of the PoE operation over the network cable (e.g., level of current, heating, etc.) is made available to the physical layer device (PHY). This information enables the PHY to infer a change in the level of inductance on the line. In response, the PHY can then adjust a characteristic of transmission by the PHY.

Abstract: An electrical fault mitigation system includes a mitigation device including a containment chamber defining a cavity, a first electrode positioned within the cavity and coupled to a first conductor, and a second electrode positioned within the cavity and coupled to a second conductor. The mitigation device also includes a first voltage source, and a plasma gun positioned within the cavity and configured to emit ablative plasma using the first voltage source to discharge energy from an electrical fault. The system also includes a first voltage limiter device configured to limit a voltage of the first conductor from increasing above a predetermined threshold to prevent a second voltage source from generating a second electrical arc between the first electrode and the second electrode when the second voltage source applies a voltage across the first electrode and the second electrode.

Abstract: An electrical switching device is presented. The electrical switching device includes multiple switch sets coupled in series. Each of the switch sets includes multiple switches coupled in parallel. A control circuit is coupled to the multiple switch sets and configured to control opening and closing of the switches. One or more intermediate diodes are coupled between the control circuit and each point between a respective pair of switch sets.

Abstract: Systems, methods, and devices are presented for mitigating arc fault events in a photovoltaic system. An aspect of this disclosure is directed to a photovoltaic system for generating electrical power. The photovoltaic system includes one or more solar panels, and one or more shuttering assemblies, each of which is configured to selectively limit the quantity of light received by one or more of the solar panels. One or more sensing devices detect characteristics of an arc fault event in the photovoltaic system, and output signals indicative thereof. A control module is operatively connected to the shuttering assemblies and the sensing devices. The control module is configured to direct the one or more shuttering assemblies to reduce the quantity of light received by at least one of the one or more solar panels in response to the output signals indicating there is an arc fault event in the photovoltaic system.

Abstract: A display mount is provided for a vehicle, such an aircraft. The display mount includes, but is not limited to a support frame and a display accommodation device. The support frame is designed for incorporation in a supply channel, and the display accommodation device is designed to receive a display. The display accommodation device is connected to the support frame such that the display accommodation device is movable with a combined rotational movement and translational movement relative to the support frame between a first operating position and a second operating position.

Abstract: A control circuit for controlling an arc suppression circuit includes a serial communication link communicating a serial signal therethrough. The control circuit includes a microprocessor having a serial input communicating with the serial communication link. The microprocessor generates a control output signal in response to the serial signal. The control circuit further includes the arc suppression circuit having an electrical contact and operating in response to the control output signal to reduce an arc at the electrical contact.

Abstract: A device that allows standard non-load break disconnect switches to become full load break disconnect switches in that they can interrupt high levels of their rated current with no arcing or burning when the switch is opened under load in direct current use on electric railways, electric trolley bus systems, mine operations and motor controls.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: An electrical power diagnostic system includes a system housing, a power saw management system, and a user interface. The system housing is electrically connected with the power unit of the power saw, wherein the system housing includes a control panel provided thereon for allowing a user to adjust an operational parameter through the control panel. The power saw management system includes a control processor mounted within the system housing to electrically communicate with the power saw, wherein the control processor is pre-programmed to manage operational parameters of the power saw and supervise actual operation of the power saw machine and the saw blade in such a manner that when abnormal operating condition of the power saw machine is detected, the control processor is adapted to selectively adjust the operational parameters of the power saw machine for stopping the abnormal operating condition from continuously happening.

Abstract: The present invention provides a unit with a built-in control circuit capable of cost reduction. The unit of the present invention is an unit with built-in control circuit comprising a ground line, a control circuit including a plurality of terminals to be connected to an IC-chip, and a plurality of protect elements connected to the terminal and the ground line.

Abstract: A disc apparatus which can judge accurately whether or not a spindle motor is at fault due to a short circuit is provided. A disc apparatus (1) includes a spindle motor (3) which rotates a disc (2), a differential operational amplifier (5) which successively detects output voltages of the spindle motor (3), and a failure judgment unit (10) which calculates an average voltage of the plural output voltages and judges whether or not the spindle motor (3) is at fault in accordance with the average voltage and the output voltages. When counting number of occurrences of a specific state which indicates that one of the two output voltages detected successively is larger than the average voltage and other of the two output voltages is smaller than the average voltage, the failure judgment unit (10) judges that the spindle motor (3) is at fault.

Abstract: An arc fault circuit interrupter includes line and load terminals, separable contacts in series between the terminals, a neutral conductor, and an operating mechanism opening and closing the contacts and tripping open the contacts in response to a trip signal. A current transformer senses current flowing through the contacts. A voltage sensor detects voltage zero crossings between the load terminal and the neutral conductor. A processor detects a resistive series arc in series with the contacts. A processor routine determines, for each half cycle, samples of the sensed current, an offset value from an average of sensed current samples proximate the voltage zero crossings for the corresponding half cycle, adjusted sensed current samples as adjusted by the offset value, a profile corresponding to a resistive series arc as a function of the sensed current samples and the adjusted samples, and the trip signal in response to occurrences of the profile.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: An electromechanical/solid-state AC relay has an electromechanical winding coil that moves an armature to force mechanical contacts to open or close. Electrical arcing across the mechanical contacts that occur as the contacts are opening or closing can damage and severely reduce the lifetime of the relay. Contact arcing is prevented by pulsing a triac on for a short period of time just before and after the mechanical contacts make or break contact. The triac limits the voltage difference across the mechanical contacts to less than one volt to prevent arcing. The triac is turned off after the mechanical contacts finish moving, reducing the heating and average power through the triac. A zero-sampling circuit that detects when the AC input voltage switches across 0 volts and activates a control integrated circuit to switch on the triac during zero-crossings to minimize power surges.

Abstract: The method for mains-synchronous switching of circuit breakers comprises the following method steps: measurement of the current flowing through a circuit breaker (9) and measurement of a mains voltage on a first side of the circuit breaker (9), additional voltage measurement on a second side of the circuit breaker (9), feeding of all the measurement signals to a control device (18), deciding in the control device (18), on the basis of the characteristic data stored there, which measurement signal will be used as the reference value for the mains-synchronous tripping of the circuit breaker (9), generating a switching command, which initiates the mains-synchronous switching of the circuit breaker (9) on the basis of this decision, and carrying out the switching command by the circuit breaker (9).

Abstract: A switching circuit for connecting a power source to a load is described. The circuit comprises a first relay and at least one second relay in parallel arrangement with the first relay. The switching circuit is arranged such that in the event of a fault condition occurring that requires the disconnection of the power source from the load, the at least one second relay opens while the first relay remains closed. In this manner, a reliable disconnection of the load from the switching circuit is achieved.

Abstract: Provided is a method and apparatus for controlling a motor of a disk drive. The method is used to stably control the startup current of a motor by considering a voltage drop and the disk drive uses the method. The method includes managing power-on reset retry information generated during the startup of the motor and determining the startup current of the motor that corresponds to a power-on reset retry count included in the power-on reset retry information.

Abstract: Disclosed herein is an apparatus for detecting an arc fault, which prevents a malfunction caused by a conventional current detecting method by detecting a source voltage applied onto a conductive wire to determine whether there is an arc fault, prevents a malfunction with respect to a pseudo arc signal by dividing a current detecting route into two according to the magnitude of a load current occurring onto the conductive wire to determine whether there is the arc fault by voltage detection, and lessens the danger of a fire by reducing a circuit break time according to the magnitude of the load current. A voltage detector detects the arc fault by use of two detecting routes. Each route differs in a filtering value of a filter, presence/absence of level limit, an amplification factor of an amplifier, an accumulation value of a comparator, etc. according to the magnitude of a load current occurring on a conductive wire, thereby reducing a circuit break time.

Abstract: An arc fault circuit interrupter includes separable contacts, an operating mechanism adapted 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 a peak detector determining a peak amplitude of a current pulse of the current flowing in a power circuit. A microprocessor determines whether the peak amplitude of the current pulse is greater than a predetermined magnitude. A plurality of routines including a time discounted accumulation algorithm, a short delay algorithm and a series time discounted accumulation algorithm, employ the peak amplitude to determine whether an arc fault condition exists in the power circuit.

Abstract: A contactor having a separable conduction path, an actuator, a magnetic stator and armature, and a controller, is disclosed. The actuator is in mechanical communication with the separable conduction path, and the magnetic stator and magnetic armature are arranged in field communication with each other and with an excitation coil responsive to a coil current that serves to generate a magnetic field directed to traverse the stator and the armature. The controller has a processing circuit adapted to control the coil current in response to the current and voltage at the coil such that the coil current is controlled in response to the position and closing speed of the separable conduction path prior to the separable conduction path closing during an open-to-close action.

Abstract: A method of eliminating arc flash in a motor control center is disclosed. The method includes sensing an arc flash corresponding to the motor control center. In response to sensing the arc flash, and subsequent to a delay, determining whether the arc flash continues, and in response to determining that the arc flash continues, triggering an arc crowbar.

Abstract: A universal hybrid solid-state switchgear for power transmission or distribution systems incorporates a fast mechanical switch and solid-state power electronics switching circuits to provide circuit breaker and fault current limiting applications.

Abstract: Low cost apparatus and methods of detecting arc faults for better discriminating electrical events. The arc fault detection apparatus includes a current sensor, a di/dt input sense circuit, a dv/dt input sense circuit, and a processing unit. The current sensor monitors a power line current, and provides high frequency components of the power line current to the di/dt input sense circuit. The dv/dt input sense circuit monitors a power line voltage. The di/dt and dv/dt input sense circuits generate signals carrying information relating to changes in the power line current and the power line voltage, respectively. The processing unit analyzes these changes in the power line current and the power line voltage to discriminate detected electrical arcing events from nuisance loads with increased accuracy.

Abstract: An apparatus includes a first circuit detecting when an absolute value of a current signal is less than a first predetermined value and outputting a signal after a first time period. A comparator compares that signal to an envelope of a rectified current signal, in order to provide an output with a plurality of pulses that persist for a relatively longer time for a relatively small value of the envelope, and persist for a relatively shorter time for a relatively large value of the envelope. A second circuit enables the comparator output if the rectified current signal exceeds a second predetermined value, and disables the comparator output after the rectified current signal is below the second predetermined value for a second time period. A third circuit accumulates the pulses and outputs a signal representative of a wet track arc fault.

Abstract: A method and device for thermal conduction is provided. A thermal interface device and method of formation is described that includes advantages such as improved interfacial strength, and improved interfacial contact. Thermal interface devices are shown that include at least some degree of mechanical bonding through plastic deformation of metal. Embodiments of composite thermal interface devices are shown that provide reduced device cost by limiting use of expensive materials such as diamond, or gold. Device cost is also reduced in a number of embodiments by reducing a number of manufacturing steps in the formation of integrated circuit devices.

Abstract: The arc suppression system for electrical contacts includes a transistor, such as an IGBT, which is connected across the contacts. A control circuit controls the operation of the transistor such that the turning on of the transistor results in a current path around the contacts, thereby tending to prevent arcing across the contacts. A current sensor, such as a flyback transformer, is positioned in series with the contacts, wherein when the contacts open, current is interrupted through the contacts and the transformer, a secondary voltage results which is applied to the transistor, which tends to maintain the transistor on for a time which is sufficient to allow the contacts to either open or close without an arc.

Abstract: The hybrid relay may include a plurality of input and output terminals, and a voltage supply terminal. The hybrid relay may also include an electromagnetic coil connected to the input terminals and a latching mechanism that may include first and second contacts movable between open and closed latched positions based upon the electromagnetic coil. The first contact may be connected to the voltage supply terminal so that the second contact provides a switched voltage supply. The hybrid relay may also include an output transistor having a control terminal and having conduction terminals connected to the output terminals of the hybrid relay. A transistor driver may be connected between the switched voltage supply and the control terminal of the output transistor.

Abstract: A closed-loop control system for a DC motor includes a DC motor 12, a current sensor 14 for determining a current of the motor, a voltage sensor 32 for measuring a voltage of the motor 12, and a micro-controller 33. The micro-controller is constructed and arranged to (1) compare the determined current with a set point and output a pulse width modulated (PWM) duty cycle to control the motor, and (2) calculate a PWM duty cycle limit based on the measured voltage and compare the outputted PWM duty cycle to the PWM duty cycle limit such that when the outputted PWM duty cycle greater than the PWM duty cycle limit, the outputted PWM duty cycle is set to the PWM duty cycle limit. A method, in a DC motor, of preventing a current surge during severe voltage changes is also disclosed.

Abstract: A safety-guard detective circuit of a fan motor includes a resistor being adapted to limit a large current input into the motor driver circuit, and a discharge member being adapted to perform grounding to discharge the large current limited by the resistor. The resistor and the release member are commonly connected to the third lead of the motor driver circuit.

Abstract: The arc suppression system for electrical contacts includes a transistor, such as an IGBT, which is connected across the contacts. A control circuit controls the operation of the transistor such that the turning on of the transistor results in a current path around the contacts, thereby tending to prevent arcing across the contacts. A current sensor, such as a flyback transformer, is positioned in series with the contacts, wherein when the contacts open, current is interrupted through the contacts and the transformer, a secondary voltage results which is applied to the transistor, which tends to maintain the transistor on for a time which is sufficient to allow the contacts to either open or close without an arc.

Abstract: A method for controlling the closing operation of a switching device, which is disposed on an electrical network connected to an inductive component. The method requires first data related to the electrical characteristics of the inductive component and the electrical network. Based on the first data, on a predefined first storage device containing opening and closing operation sequences, a first predefined opening operation sequence is selected. Then, based on the first predefined opening operation sequence, on the first storage device, a first predefined closing operation sequence is selected.

Abstract: Disclosed is a vehicle which includes an electrical system monitoring system which results in detecting arcing in the electrical distribution system of the vehicle and the ability to provide notification and protection for such arcing. The system functions to monitor the electrical distribution system of the vehicle to sense the frequencies of signals in the system using appropriate filtering. One type of filtering which may be used is based upon a heterodyning circuit which provides variable frequency filtering for filtering a signal representative of the current in at least one electrical circuit of the vehicle. The heterodyning circuit output is configured to produce a signal which may be logarithmically related to the filtered signal. If the output signal exceeds a predetermined limit (representative of noise) for a predetermined period (representative of a typical arc duration), the system generates an arc signal.

Abstract: A safety interlock apparatus for an electrical device includes a DC power supply, a ballast power supply including a ballast control circuit that controls a ballast power circuit, and a lamp. A relatively low voltage electrical connection is present between the DC power supply and the ballast control circuit. A relatively high voltage electrical connection is present between the lamp and the ballast power circuit. A safety interlock switch is positioned on the relatively low voltage electrical connection, the switch having a closed state wherein the relatively low voltage is supplied to the ballast control circuit and an open disconnected state wherein the relatively low voltage electrical connection is disconnected. A panel is fixable to the electrical device frame, and is selectively movable to expose the lamp for removal.

Abstract: A self-testing arc fault or ground fault detector includes arc fault detecting circuitry and components. The detector includes a testing circuit which tests at least part of the circuitry and components and generates a recurring signal when the test completes successfully. If the test does not complete successfully, the signal is lost. This loss of signal is signaled by an indicator connected to the testing circuit. In one version, the loss of signal activates a circuit interrupter which disconnects the load side of the detector from the line side.

Abstract: A method is shown of predicting failure of resistive element heaters using a compiled database of measured ratiometric factors affecting heater life. The method can either be carried out actively, by continuously measuring known factors affecting heater life and decrementing a count of the remaining heater life, or the method may be carried out passively by estimating the operating profile and the averages within each segment of the profile, of the factors affecting heater life.

Abstract: A system for detecting arcing faults in an electrical distribution network having a line conductor carrying an electrical signal between a power source and a load, the system being capable of detecting series arcs, line-to-neutral arcs and line-to-ground arcs. The system includes a sensor coupled to the line conductor for monitoring the electrical signal and generating a sensor signal representing the electrical signal. The system generates an arc-indicative signal in response to the sensor signal having characteristics indicative of an arcing fault. The system can include a testing system in which a test wire is coupled to the sensor simultaneously with the line conductor and a test signal is periodically produced on the test line. The sensor simultaneously monitors the test signal and the electrical signal and produces a sensor signal representing both the test signal and the electrical signal when the test signal is present on the test line.

Abstract: An open circuit failure monitoring apparatus for controlled electrical resistance heaters is disclosed. The heater failure monitoring apparatus allows controlled electrical resistance heaters to be continuously monitored for open circuit failures without applying an operational current flow through the heater, regardless of the operational status of the heater and without significant power consumption during periods when the heater is not operated. The failure monitoring apparatus includes a reactive current limiting element, such as a capacitor, and a current monitoring circuit. The capacitor is connected in parallel with the contact switch used to control line voltage applied to the resistive load. The reactance of the capacitor provides a small but continuous test current capable of being detected by the current sensing component, but not large enough to consume significant power.

Abstract: An overcurrent protection system containing (1) a current sensing means; (2) a first switch coupled to the current sensing means; (3) a voltage sensing means; (4) a PTC device; and (5) a second switch coupled to the voltage sensing means. In one type of system, the second switch is connected in series with a parallel combination of the first switch and the PTC device; and the voltage sensing means is connected in parallel with a series combination of (i) the second switch and (ii) the parallel combination of the first switch and the PTC device. In another type of system, the first switch, the PTC device and the voltage sensing means are connected in parallel with each other; and the second switch (i) is a switch which latches in the open position and (ii) is connected in series with the parallel combination of the first switch, the PTC device and the voltage sensing means.

Abstract: A ball grid array (BGA) integrated circuit package which has a plurality of vias connected to a plurality of solder pads located on a bottom surface of a package substrate. Each via has a portion located within a solder pad to increase the routing space of the substrate, and a portion located outside the solder pad to allow outgassing from the via. The bottom surface also has a solder mask which covers the vias and contains a number of holes that expose the solder pads. The holes allow solder balls to be attached to the solder pads. The solder balls can be reflowed to attach the package to a printed circuit board.

Abstract: A circuit protection system employing arrangements of PTC devices and mechanical switches. The PTC device is not involved in the circuit until a fault is sensed. A current sensing relay senses an overcurrent and directs the current to the PTC device. As the voltage across the PTC device increases, a parallel arrangement of voltage sensing relays completes the operation of the protection system, and disconnects the load until the protection system is reset. The protection system may be reset manually or remotely.

Abstract: Overcurrent protection arrangements including a relay comprising two coils wound on a common magnetic core and a PTC device coupled in parallel with the relay contacts. The arrangement comprises a circuit interruption element which has a normal state which permits the flow of a normal circuit current, I.sub.NORMAL, to pass through the system, and a fault state which permits the flow of at most a reduced current, I.sub.REDUCED, substantially less than I.sub.NORMAL. A first control element is coupled in series between the power supply and the load, and is functionally linked to the circuit interruption element so that when the current through the first control element increases from I.sub.NORMAL to a relatively high current, I.sub.FAULT, the first control element can convert the circuit interruption element into the fault state.

Abstract: An electrical strike sensing system for providing an alarm if the underground boring equipment encounters a potentially hazardous condition. The system senses current carried through the equipment, as well as the voltage between the equipment and a reference. The measured current is converted to a percentage of a reference current, and the voltage is converted to a percentage of a reference voltage. The current and voltage percentages are added, and if the sum exceeds 100%, the alarms are activated. The current and voltage percentages, as well as the date and time of the strike, are stored in a nonvolatile memory.