Abstract: Circuit and method for providing over-current and overloading protection with a single additional pin. A converter controller circuit is provided that includes a voltage controlled oscillator and outputs upper and lower gating signals for driving the upper and lower driving transistors in a voltage converter, for example, in an inductor-inductor capacitor half-bridge circuit topology. A current sense input pin of the circuit receives a voltage corresponding to the current flowing in the half-bridge circuit. A feedback input pin has an external capacitor coupled to it and receives a voltage from an output voltage sensor at the output terminals. Over-current protection is provided by sensing the voltage at the current sense input pin with no external components needed. Overload protection is provided by utilizing the external feedback capacitor and the feedback input pin during overload conditions. Methods for providing over-current and overload protection are disclosed.

Abstract: A novel system for providing power over the Ethernet includes a current limit circuit for preventing an output current from exceeding a current threshold set at a prescribed level, and a foldback circuit for reducing the current threshold when an output voltage is lower than a prescribed voltage value. The foldback circuit may be controlled to operate in a high-power mode to increase the current threshold above the prescribed level.

Abstract: A power supply equipped with an independent overload protection mechanism includes a control circuit and a transformation circuit that form multiple sets of combination circuits for transforming AC power to DC power. Each control circuit is connected to a protection circuit which monitors overload operation conditions of an electronic device. In the event that an overload condition occurs, the protection circuit outputs an individual protection signal to the control circuit to stop or suspend power output on a DC power cord so that the electronic device at the rear end is not driven. Hence an independent overload protection can be achieved.

Abstract: An apparatus has power semiconductor modules, which are connected to one another via connection devices so as to form a series circuit. A short-circuiting device for short-circuiting the respective power semiconductor module is assigned to each power semiconductor module. The apparatus has a reliable and at the same time cost-effective short-circuiting device. It is proposed that the short-circuiting device is a pyrotechnical/mechanical element, which has a detonation charge and a tripping device, which can be displaced by the detonation charge.

Abstract: In a method and system for protecting a battery being charged by an electrical device, a current flowing through a cell stack of the battery is measured. If the measured current is greater than a predefined value the battery is isolated from the device. If subsequent current measurements made within a predefined time interval indicate that the measured current is less than or equal to the predefined value then the battery is recoupled to the device. If the measured current remains greater than the predefined value during the predefined time interval then a fuse is blown and the battery is disabled.

Abstract: A protection device for protecting an electronic circuit against a fault is described. The electronic circuit includes an output stage for driving a load and a driving circuit for driving the output stage. The driving circuit is configured to produce a drive signal in response to at least one input signal. The protection device includes a gating circuit and control means. The gating circuit has a first input configured to receive the drive signal, a second input configured to receive a control signal, and an output configured to activate and deactivate the output stage based on the drive signal and control signal. The control means produce the control signal in response to a detection signal representative of detection of the fault either of the load or of the output stage.

Abstract: Provided are systems and methods for protecting display components from adverse operating conditions. A lighting panel system according to some embodiments includes a lighting panel including a plurality of strings of solid state lighting devices arranged across the panel and a protection system configured to determine an adverse operating condition and adjust a lighting panel luminance setting responsive to the adverse operating condition.

Abstract: An inverter driver controls an inverter that supplies driving voltages to a plurality of discharge lamps. The inverter driver senses the abnormal operation of the plurality of discharge lamps based on a plurality of first feedback voltages corresponding to the plurality of driving voltages supplied to the discharge lamps and a plurality of second feedback voltages corresponding to the current flowing through the plurality of discharge lamps. The inverter driver is formed in a single integrated circuit.

Abstract: There is described circuit arrangement which comprises a protection element. A state of the protection element is determined in a simple and safe manner by means of a detection unit and a specification unit, in addition to an evaluation unit.

Abstract: A method and apparatus for anti-islanding of distributed power generation systems having an inverter comprising a phase locked loop (PLL), a phase shift generator for injecting a phase shift into the PLL during at least one sample period, and a phase error signature monitor for monitoring at least one phase error response of the PLL during the at least one sample period.

Abstract: A load drive device for driving an electrical load includes high-side and low-side transistors, and a switch. When the load is driven, each of the high-side and low-side transistors operates in a first mode where each of the high-side and low-side transistors is fully tuned on or in a second mode where each of the high-side and low-side transistors is controlled so that a load current flowing through the load is constant. When the load is driven, there is a first state where the high-side transistor operates in the second mode and the low-side transistor operates in the first mode and a second state where the high-side transistor operates in the first mode and the low-side transistor operates in the second mode. The switch switches between the first and second states to distribute heat generation between the high-side and low-side transistors.

Abstract: Device protection using temperature compensation. A logic module associated with groups of capacitors adjusts complex impedance planes associated with the capacitor groups to account for ambient temperature variations. In particular, the logic module is configured to adjust a center of a circle of each complex impedance plane based on an average impedance. The average impedance for a selected capacitor group includes impedance measurements for groups other than the selected group, to prevent capacitor failures in that group from skewing the average. The logic module can adjust the circle center in response to changes in average impedance over periods of time. For example, the logic module can filter measured differences in average impedance using a low pass filter, to distinguish slow impedance changes caused by temperature variations and rapid impedance changes caused by capacitor failures. The logic module can adjust the circle center in accordance with the filtered difference value.

Abstract: A power converter includes a controller having at least one input for monitoring a rate of change of an operating parameter of the power converter. The controller is configured for comparing the monitored rate of change of the operating parameter with an allowable rate of change for the operating parameter, and for generating a fault signal when the monitored rate of change of the operating parameter deviates from the allowable rate of change for the operating parameter. The operating parameter for which the rate of change is monitored may be, for example, a temperature, a current and/or a voltage in the power converter.

Abstract: An integrated circuit includes a radiation-triggered shutdown circuit that disables a critical aspect of the integrated circuit rendering the integrated circuit non-functional when the integrated circuit receives a predetermined radiation dose. That ensures integrated circuits including the radiation-triggered shutdown circuit are ITAR compliant.

Abstract: An implantable system that includes a lead and an implantable signal generator wherein the plurality of electrical contacts and the plurality of insulating regions on the lead, and the plurality of electrical connectors and the plurality of electrical insulators in the connector block are configured so that each of the plurality of electrical contacts form operable connections to the electronic circuitry through each of the plurality of electrical connector, and the insulating regions and the electrical insulators electrically isolate adjacent operable connections. Leads, and methods are also disclosed.

Abstract: A power supply device of the invention includes: a supply section that supplies power to a processing device which processes data; a load detection section that detects a load of processing executed by the processing device; a power control section that causes the supply section to increase or decrease power supply according to the magnitude of load detected by the load detection section; and an operational abnormality detection section that detects operational abnormality of the power control section. The supply section supplies predetermined power to the processing device when abnormality of the power control section is detected by the operational abnormality detection section.

Abstract: Status of a bypass source of parallel-connected UPSs is determined from a load share when a loading of the parallel-connected UPSs meets a predetermined criterion. Status of a bypass source of the parallel-connected UPSs is determined from a bypass source voltage when the loading of the parallel-connected UPSs fails to meet the predetermined criterion. The loading may include an aggregate loading, and failure of a bypass source of a UPS may be identified responsive to detecting that a load share of the UPS is less than a predetermined proportion of the aggregate loading. Alternatively, failure of the bypass source may be identified by detecting that a bypass voltage fails to meet a predetermined criterion. Bypass circuits of the UPSs may be controlled responsive to a load share and/or a bypass source voltage.

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: In one aspect, the invention provides a system for protecting a plurality of circuits including a plurality of circuit protective devices wherein each circuit protective device includes a respective nominal current rating. According to one embodiment, the system includes current sensing circuitry configured to measure a current of each circuit protective device; and a controller configured to receive each of the measured currents. According to one embodiment, the controller is further configured to determine a ratio between a total current being carried by all of the circuit protective devices combined and a total nominal current rating of all of the circuit protective devices combined and employ the ratio to determine a modified nominal current rating of each circuit protective device, respectively.

Abstract: A stray voltage detection and isolation system. The stray voltage detection portion of the system includes a water delivery system electrically isolated from an electrical transmission system of an electric utility. Meters measure an electrical characteristic between a first test-point that is electrically connected to the water delivery system and a plurality of second test-points. The second test-points are at earth grounds at locations electrically connected to the first test-point. The location of a source of stray voltage can be determined by evaluating differences in the measured electrical characteristics. The stray voltage isolation portion of the system electrically isolates a water delivery system. A controller maintains an air gap between a water source and a first storage tank or between the first storage tank and a second storage tank. The second storage tank provides the electrically isolated water.

Abstract: A power supply apparatus connected via a bus line to another power supply apparatus includes a voltage generation circuit generating a voltage, an abnormality detection circuit detecting an abnormality of the power supply apparatus including the abnormality detection circuit and outputting an abnormality detection signal, an abnormality control circuit, and an interface circuit receiving the abnormality detection signal from the abnormality detection circuit to output the signal via the bus line to another power supply apparatus, and receiving the abnormality detection signal via the bus line from another power supply apparatus to output the signal, to the abnormality control circuit and the abnormality control circuit controlling the voltage generation circuit to stop generation of the voltage in a case where receiving the abnormality detection signal from the abnormality detection circuit or in a case where receiving the abnormality detection signal from the interface circuit.

Abstract: Within a group of components in a circuit, each component in the group has a thermal detector that describes whether that component is operating at a temperature that is normal, high or fatal. A first signal representing a first component's temperature is sent downstream to a second component in the group. If the second component is operating at the first component's temperature or lower, then the first signal is passed on downstream from the second component. However, if the second component is at a higher temperature, then the second component generates a second signal that represents the second component's temperature, and sends that second signal downstream. A signal representing the highest temperature detected in the group eventually reaches a master controller that, depending on the signal received from the group, lets the group continue to operate normally, throttles the group down, or else shuts the group down.

Abstract: An apparatus can include a fault condition detector configured to detect a fault condition in an electrical system, a delta d-q power value generator configured to generate a delta d-q power value temporally corresponding to the detected fault condition, and a characterizer circuit configured to characterize the fault condition relative to the apparatus responsive to the delta d-q power value. Methods can include detecting a fault condition in an electrical system and determining changes in d-q component voltage and current temporally corresponding to the detected fault condition. Such methods can further include characterizing the fault condition responsive to the determined first and second changes and controlling an apparatus based on characterizing the fault condition.

Abstract: The current differential relay operates without adjustable settings, and includes a phase current differential element with a predetermined threshold, responsive to local phase current values and remote phase current values, to detect three-phase faults and producing a first output signal if the threshold value is exceeded. Either a negative sequence current differential element or two phase current differential elements, also having predetermined threshold values and responsive to the local and remote phase currents, detect phase-to-phase faults and phase-to-phase-to-ground faults and produces a second output signal if the predetermined threshold is exceeded. A negative sequence or zero sequence current differential current element, with a predetermined threshold value is responsive to the local and remote phase currents to detect phase-to-ground faults and to produce a third output signal if the threshold is exceeded.

Abstract: An electric cutoff circuit for preventing overheating of a load. The current shutoff circuit includes an FET connected to a motor circuit. A relay fault detection circuit is connected to the motor circuit to detect potential at the motor circuit. A CPU sends a control signal to a relay. The CPU determines whether a fault has occurred in the relay based on the control signal sent to the relay and the detection of the relay fault detection circuit. When determining that a fault has occurred in the relay, the CPU opens the FET to configure an open circuit with the motor circuit.

Abstract: An electrical power strip has a base, a power cord and a control module. The base has at least one primary receptacle and at least one secondary receptacle. The control module is connected to the power cord and has two power input terminals, at least one primary contact set, a voltage regulating circuit, a current indicating circuit, a comparator, a driving circuit and at least one secondary contact set. The two power input terminals are connected to the power cord. The voltage regulating circuit is connected to the two power input terminals and outputs a regulated voltage. The current indicating circuit is connected to the primary contact set and the voltage regulating circuit to output direct current. The comparator checks for the regulated voltage and the direct current and then outputs a control signal. The control signal applies power to the secondary contact set.

Abstract: A test device is provided for testing stability of a computer when the computer is started up or shut down. The test device includes a monolithic chip and a switch module. The monolithic chip includes an input port and an output port. The input port receives a high level or a low level signal from the computer. A test control module is disposed in the monolithic chip. The switch module includes an input pin coupled to the output port of the monolithic chip and a pair of output pins corresponding to the input pin. The pair of output pins is connected to the computer, for controlling the computer to be started up or shut down. The input port of the monolithic chip is connected to the computer for detecting a state of the computer.

Abstract: A driver circuit for an electronic switch, the driver circuit having a first input for receiving a first control signal, and a second input for receiving a signal from a current sensor, the driver circuit further including a shut-off circuit for operating the electronic switch to cause an interruption to current flow in the event of a fault condition arising, such as current through the electronic switch exceeding a predetermined threshold, wherein operation of the shut-off circuit can be invoked by a predetermined event at the first input.

Abstract: The application of electric power from a power source to a load is controlled by detecting the magnitude of electric current flowing to the load and producing a first signal level that is indicative of that magnitude. The first signal level is compared to a reference signal level which comparison produces an output signal. Either the first signal level or the reference signal level is altered in response to variation of voltage applied to the load. This results in the output signal indicating when electric power consumed by the load exceeds a threshold level. The flow of electric current from the power source to the load then is controlled in response to the output signal.

Abstract: The present invention is directed to a method and apparatus for improving operational reliability during a loss of a phase voltage (LOV) in a multi-phase power system, wherein a voltage representative of the LOV phase is calculated. The representative voltage is used for computing a reference polarizing voltage suitable for a protection unit.

Abstract: Systems and methods for providing ride-through for interruptions in the power supplied to drives that are used to control equipment such as downhole submersible pumps. In one embodiment, a variable speed drive includes converter and inverter sections, a capacitor bank and a control system. The drive shuts down the converter section upon detecting a disruption in the AC input power and continues to generate output power by drawing on the energy stored in the capacitor bank. When the AC input power returns (or begins to return) to normal, the drive resumes operation of the converter section in a controlled manner (e.g., by presetting the firing angle of the SCR's in the converter to match the voltage across the capacitor bank.) The drive thereby limits the current that recharges the capacitor bank and prevents sudden inrushes of current that could damage the drive.

Abstract: A nominal setpoint value of the admissible power consumption of a household appliance is respectively set for each electrical component. The actual value of the current consumption of the household appliance is measured according to the electrical components used and is compared with the corresponding setpoint value. A safety measure is triggered if the nominal value is exceeded. The novel household appliance is provided with a control device that includes a device for respectively regulating a nominal value of the admissible current consumption for the electrical components of the household appliance, a device for measuring the actual value of the current consumption of the household appliance according to the electrical components used, and a comparator for comparing the actual value with the corresponding nominal value. The unit triggers a safety measure if the setpoint value is exceeded.

Abstract: A method for detecting line under frequency (LUF) events and initializing load shedding of loads located near the electrical disturbance without customer and utility intervention is disclosed. In one example embodiment, the LUF detection system measures the time period of each power line cycle and then compares the measured time period to a utility-configurable trigger period. If the cycle length is greater than or equal to the trigger period, a counter is incremented. If the cycle is less than the trigger period, the counter is decremented. If the counter is incremented to a counter trigger, an under-frequency condition is detected and the LUF response either controls the load or temporarily disconnects it. A restore response is initialized after the frequency rises above a restore value and an under-frequency counter counts down to zero.

Abstract: The present invention discloses a fan protection apparatus and related method thereof. The fan protection apparatus has a control circuit and a counter. According to the fan protection method, the user can set the acceptable restart number and the special time for auto restart. The fan protection apparatus and method can force to stop the fan when the fan encounters an abnormal situation. When the stop time has passed, the fan is automatically restarted. The present invention counts the number of restarts. If the number of restarts equals the set number and the abnormal situation also cannot be eliminated, the present invention cuts off power to the fan.

Abstract: A tester for an arc fault circuit interrupter that can selectively simulate and apply electrical arc faults and nuisance loads to at least one device under test (DUT). The tester includes a power supply, a test controller, and test circuitry coupleable to a DUT. AC power input is provided to the DUT and the power supply, which regulates the AC power input to a DC level for powering the test controller. The test circuitry full wave rectifies AC current returning from the DUT, and the test controller controls a switch in the test circuitry. When the switch is on, the AC current flows through the DUT, the full wave rectifier, the load, and the switch to ground. To simulate an arcing condition, the test controller turns the switch on and off at random intervals. To simulate a nuisance load condition, the test controller turns the switch on and off at periodic intervals. In this way, proper operation of the DUT can be verified under both arcing and nuisance load conditions.

Abstract: Protection and filtering functions are provided for external circuits by internal circuits that use controlled elements.

Abstract: An unbalanced current detection circuit determines when a multi-phase, normally-balanced load is unbalanced. The detection circuit of the present invention includes a plurality of current-squaring circuits, each squaring a sensed current of one of the phases. A summing circuit produces a sum of the squares of the currents. If the load is balanced, this sum should be relatively constant, perhaps changing only slowly over time, with little or no ripple from that relatively constant value. In an unbalanced current condition, the sum of the current squares would consist of an average (dc) component plus a ripple (ac) component. If the amplitude of the ripple current exceeds a threshold, it is determined that the currents are unbalanced.

Abstract: In a digital protection relay with a time sync function, the sampling timing of which is specified based on a reference timing transmitted from a time signal generator to a time sync unit, with a determination value. The time sync unit includes a reception circuit that receives a discrimination code and time data transmitted from the time signal generator, a code discrimination circuit that discriminates the reference timing on condition that the received discrimination code coincides with a desired code, a time calculation circuit that calculates the sampling timing on the basis of the discriminated reference timing and the time data, and a sampling sync circuit that specifies the sampling timing of a digital quantity of electricity on the basis of the calculated sampling timing.

Abstract: Systems and methods for detecting faults in RVDTs and LVDTs are described. In an exemplary embodiment, a sum of secondary voltages V1 and V2 from a transducer is obtained by adding the secondary voltages together, i.e.; V1+V2. This sum of secondary voltages theoretically should be constant for all LVDT/RVDT positions, since the total length of the secondary transformer is constant. An electrical fault in the primary or secondary windings generates a corresponding change in the sum of secondary voltages. By comparing this shifted value to a reference value which is representative of a no-fault condition, an error value is created which indicates the magnitude of the shift in the sum of the secondary values. Depending upon the magnitude of the error value, certain actions are taken.

Abstract: There is provided an apparatus for producing a trip signal to activate a circuit breaker in an alternating current power line, said apparatus comprising: a sensing circuit operable to sense values representing: a phase difference between current and voltage in said power line; and current amplitude in said power line; a comparison circuit operable to compare said sensed values of phase difference and current amplitude with a trip characteristic defining fault conditions and non-fault conditions and to generate a fault indication signal when a fault condition arises; a fault discriminator operable in response to said fault indication signal to generate a fault-identifying signal discriminating between: a first class of fault in which a mean current value after said fault indication increases relative to a mean current value before said fault indication; and a second class of fault in which a mean current value after said fault indication does not increase relative to a mean current value before said fault indi

Abstract: A connector system includes a circuit board having a plurality of holes extending therethrough. First and second connector bodies, each having a front wall, are positioned on first and second sides of the circuit board, respectively. The front walls of the connector bodies have a plurality of signal pin openings aligned with the circuit board holes. A plurality of signal pins extend through the signal pin openings of the first and second connector bodies and through the circuit board holes. At least one of the plurality of circuit board holes has a diameter larger than a diameter of the signal pin extending therethrough, such that walls of the at least one circuit board hole are spaced apart from the signal pin extending therethrough.

Abstract: In an electronic control apparatus having a one-chip microcomputer and a power output circuit, a voltage abnormality detecting circuit is provided to detect whether an output voltage of each power output circuit is set to a voltage in a predetermined range. A current abnormality detecting circuit is also provided to detect that a current flowing into each power output circuit is in an excessive current condition or in a low current condition. The microcomputer is reset when the detected output voltage or the detected current is abnormal.

Abstract: An arc fault protection device protects a branch circuit portion of an electrical distribution system. The branch circuit is connected to a load. A first sensor detects fluctuations in load current, while a second sensor detects fluctuations in line voltage. The polarities of the fluctuations are compared, and the comparison indicates whether an arc signature, potentially indicative of an arc fault, is located in the branch circuit portion or located in a remainder of the electrical distribution system.

Abstract: A frequency measuring device can measure the frequency of a noisy power system at high speed. The system voltage is measured at timings obtained by equally dividing one reference-wave period. Voltage vectors are calculated which have tip ends, each voltage vector consisting of a real part of a first measured voltage and an imaginary part of another voltage measured at timing 90 degrees before the first measured voltage. The length of a chord connecting tip ends of adjacent voltage vectors is calculated. A voltage root-mean-square value is calculated from voltages measured between two timings spaced from each other by the one reference-wave period. Chord lengths obtained between two timings spaced from each other by the one reference-wave period are summed. Based on the total of the chord lengths and the voltage root-mean-square value, there is calculated a phase angle between two adjacent voltage vectors, from which the system frequency is calculated.

Abstract: A circuit for detecting an overcurrent in an element in which an A.C. supply current flows, including a first comparator, assigned to the halfwaves of a first sign of the A.C. power supply, receiving on a reference input a first reference voltage setting a first one of the thresholds, a second comparator, assigned to the halfwaves of a second sign of the A.C. power supply, receiving on a reference input a second reference voltage setting a second one of the thresholds, and an input stage providing, to respective interconnected read inputs of the comparators, a voltage proportional to the voltage across the element, the stage including at least one first resistive element introducing a voltage drop between a first one of the terminals of the element and the read inputs.

Abstract: The invention relates to a control circuit for a direct current motor with a reverse pole protection device, which is connected to the electric circuit of the electrolytic capacitor and the free-wheeling diode in order to reduce losses in the reverse pole protection device.

Abstract: Disclosed is a method for detecting a fault by using harmonics and a state transition diagram. When the fault occurs on transmission lines, the fault is detected by using harmonics and the state transition diagram. Two logic signals are outputted by using apparent impedance of a steady state characteristic and a sum of harmonics components of a transient state characteristic. Such two logic signals are used as input parameters of the state transition diagram so that the state of an electric power system is presumed based on a state transition of the electric power system. It is possible to prevent a distance relay from being malfunctioned under an increase of load and unstable voltage. The state of the electric power system is presumed by using harmonics and the state transition diagram, and the fault on the transmission line is reliably detected.

Abstract: Switching contacts of a switching device are provided to ensure optimum service life. An optimum switching point, in terms of the load of one of the switching contacts, is determined depending on a current path that is measured during the switching process and the switching point is shifted by a delay time from switching operation to switching operation. The optimal switching point is preferably determined by self-calibration of the switching device.

Abstract: A digital protective relay for power systems includes a memory location for storing information entered by an operator concerning the operation of the relay. Conventional reports of the relay will include a reference to such operator-entered information. This information will include particular actions taken by the operator relative to the relay, as well as notes made by the operator on particular actions and/or entry of and changes to the relay settings. The entered information can be conveniently retrieved by the operator.

Abstract: An integrated solenoid system including a single housing containing a solenoid, a controller and one or more electrical connections. The controller includes temperature compensating means and/or voltage compensating means thereby providing predetermined, substantially constant currents to said solenoid. The housing includes an integral two-part end cover.