Abstract: The disclosure provides a Lorentz constraint angle estimation method and a system in a non-Gaussian environment; the method includes the following steps: constructing an N-time slot received signal model based on a non-Gaussian noise environment to obtain a reflected signal; constructing a cost model based on Lorentz norm by a difference value between an actual received signal and the reflected signal, and performing an angle estimation by combining with an atomic norm to obtain a signal sparse reconstruction model; constructing an augmented Lagrangian function by the signal sparse reconstruction model, and carrying out the iterative update on the augmented Lagrangian function to obtain a reconstructed signal; and analyzing the reconstructed signal and searching spectral peaks globally to obtain spatial spectral peak points, and completing an angle estimation of the reconstructed signal.

Abstract: A method is given for deriving a backup path routing spare capacity template that is feasible, scalable, adaptive, much faster, and near global optimal in redundancy reduction. The method includes determining working paths, aggregating the working paths into a first matrix, determining backup paths, aggregating the backup paths into a second matrix, and deriving the template from the first and second matrices. A method is also given for successively approximating the optimal spare capacity allocation needed for a network. The method includes, determining the link cost associated with a selected traffic flow's backup path, determining an updated link cost that is less than the current link cost, determining a backup path with the updated link cost, and notifying the rest of the network of the backup path.

Abstract: A circuit bypass device (30) having terminals (70, 80) is connected to contacts (70, 80) of a cell (20) to provide a conductive path (40) in response to voltage excursion therebetween. Device (30) includes: a conductive shunt (40), coupled to contacts (70, 80), that is movable from a normally non-conductive position to a conductive position between terminals (70, 80); a detector (50), coupled to conductive shunt (40), for sensing voltage excursion beyond specified limits between contacts (70, 80); and an actuator (60) having a heat-to-recover shape memory metal alloy that is formed to contract when detector (50) senses the voltage excursion, for moving conductive shunt (40) from the non-conductive position to the conductive position. The formed alloy is preferably spring-shape which contracts translationally and torsionally.

Abstract: An electronic automatic energizing damping device for connection to a source of electrical energy to protect and safeguard continuously all the devices, instruments, equipment and systems, connected to the source. The device comprises a control stage and a power stage. The control stage monitors the operating conditions of both the A.C. line and the load energized by it via the power stage, in order to detect irregularities in any of the programmed parameters of the voltage or the current, and supplies control signals that regulate the power stage. The power stage supplies the energy of the network to the load, according to the commands of the control stage. The control stage features a voltage sensor circuit, a current sensing circuit, a comparison circuit to receive the output of the voltage sensor circuit and an energy relay control circuit. The power stage comprises a surge breaker and suppressor, and an optical interface circuit.

Abstract: Among a plurality of power supply circuits arranged in a power supply monolithic integrated circuit, output voltages of power supply circuits except for an external microcomputer power supply circuit are monitored by a protective circuit. When an abnormal output appears at least one of the power supply circuits, the outputs of all the power supply circuits except for the microcomputer power supply circuit are cut off.

Abstract: A ground fault interrupter circuit is disclosed, comprising a high-voltage input from a public utility transformer, polarity reversal means coupled to the high-voltage input with polarity-switchable output coupled through a thyristor to a relay means. Radio frequency (RF) detection means are coupled to the thyristor gate, causing the thyristor to energize the relay and interrupt load power when radio frequency interference is detected from the load. The RF detector means comprises a plurality of RF chokes and resistor-capacitor pairs feeding a rectifier diode coupled to the thyristor gate. When RF is detected, the diode feeds negative direct current to the thyristor gate, interrupting conduction of the thyristor and the LOAD.

Abstract: In a four-pole circuit breaker having U, V, W and N poles for protection of corresponding phases, only an N phase signal, which is reproduced by a current signal reproducing circuit in response to a current flowing through an N phase line, is amplified by a rated current reducing circuit and supplied to a maximum phase signal selection circuit together with other phase signals.

Abstract: A motor control method for determining the temperature of a motor wherein the operation and nonoperation times of the motor are monitored, an estimated temperature is determined as a function of the monitored times and predetermined temperature rise and temperature fall characteristics of the motor, and the motor is stopped and/or an alaram signal is generated if the estimated temperature exceeds a predetermined temperature.

Abstract: Flashover protection is provided for a locomotive propulsion system including a plurality of d-c traction motors each having a commutator subject to flashovers, a traction alternator having armature and field windings and a rotor driven by a prime mover, a controllable source of excitation current connected to the alternator field, and means including an electric power rectifier for connecting the alternator to the motor commutators. It comprises means for producing a fault signal whenever a flashover occurs in any motor, a solid-state controllable electric valve connected between the excitation current source and the alternator field and having alternative conducting and non-conducting states, and means for changing the valve from conducting to non-conducting states in response to a fault signal being produced, whereupon the magnitude of excitation current in the alternator field is rapidly reduced toward zero and the alternator's output current is correspondingly decreased whenever a flashover occurs.

Abstract: The sectionalizer comprises a means that automatically sections a circuit under preset conditions, for the purpose of insulating and signaling the line defect, when said sectionalizer is mounted between some contacts fixed to an insulating support.The sectionalizer consists of a conductor tube which, independently of other elements, includes an electromagnetic triggering mechanism or device formed by an electromagnet functionally associated to a mechanical multiplier which is comprised by two arms that, in the inoperative position of the electromagnet, sustains a triggering rod maintaining the contact of the sectionalizer, while the activation of the electromagnet entails liberation by the arms of the multiplier, of the triggering rod, producing the opening of the circuit.

Abstract: A semiconductor integrated circuit includes a semiconductor chip having a predetermined circuit device and a PN junction diode group formed on the surface thereof. The PN junction diode group is supplied with a constant current in the forward direction, whereby the potential difference between the terminals thereof changes according to the surface temperature of the semiconductor chip. A potential difference generating circuit generates a fixed potential difference corresponding to a predetermined limit temperature of the chip surface, whereby the potential difference between the terminals of the PN junction diode group is compared with the fixed potential difference. As a result, when the determination in made that the temperature of the semiconductor chip surface reaches the limit temperature, the operation of the circuit device is temporarily or completely halted.

Abstract: For a preset period following application of a closing order, the semi-conductor of the static power switch, supplied with DC voltage, is controlled by a regulating circuit so as to operate as a current generator limiting the current to a value much lower than its rated value. A fuse acts as measuring shunt. The switch can comprise a circuit breaker function. In this case, the fault detection circuit measures the voltage at the terminals of the semi-conductor and supplies an opening signal when this voltage exceeds a preset threshold.

Abstract: A self diagnosing circuit for a load control circuit is disclosed, which detects the state of a driving line connected with a load and protects a load driving circuit by turning off transistors in the load driving circuit, when a grounding accident occurs, in which, in the case where an error is produced so that the load doesn't work normally, responding to a control signal, a process is executed, corresponding to the content of that error and the content of that error is stored or made known to the exterior through display means.

Abstract: A circuit for the protection the contacts of a switch device such as a reed switch when used in a control circuit. The protection circuit isolates the switch contacts from the load it is controlling by establishing parallel electrical current paths between two inputs. Two such parallel paths provide for a symmetrical bi-directional current flow within the protection circuit. Each parallel path contains a controlled switching device which conducts the current in the respective parallel path when the input polarity is in a given direction. The controlled switching device may be controlled from a polarity sensing in the primary branch which contains the switch device. A single parallel path between inputs can be used to provide polarized DC operation. Diodes in the primary path containing the switch device provide for polarity sensing for control of the controlled switch devices in the parallel paths.

Abstract: A protection circuit which electrically isolates logic level and high-side circuits and detects high side power device fault conditions at the isolated, logic level side of the circuit. When an overvoltage or overcurrent condition occurs at the power switching device, a protection circuit disables the conduction of current through the current carrying terminals of the switching device, preventing damage from occurring to the device. Activation of the protection circuit effects an increased current flow in the secondary and primary coils of the isolation transformer between the low side and high side elements. Voltage at the primary coil of the isolation transformer is monitored by low level circuitry to detect the rise in current, indicating a fault to the system controller upon detection.

Abstract: A monolithic integrated circuit (M) includes a power device (Q3, Q4) for driving an inductive load (L) and a control device for the power device. The control device comprises a voltage limiting circuit which includes a first transistor (Q2) responsive to negative impulses of the supply voltage and a second transistor (Q5) which is controlled by the first transistor for controlling re-firing of the power device in case of a negative pulse of the power voltage during a quenching period of the power device. The monolithic integrated circuit includes a substrate (5) having a substrate surface forming a supply voltage terminal of the power device and having a substrate voltage. An annular pocket (40) is formed in the substrate to surround or at least partially contain at least the first transistor (Q2) of the voltage limiting circuit.

Abstract: A negative overvoltage protection circuit for an insulated vertical PNP transistor the emitter whereof defines the input, the collector whereof defines the output and the base whereof is connected to an NPN driving transistor. In order to maximally extend the negative overvoltage which can be applied to the output, the protection circuit comprises an output voltage sensor, a voltage reference, a comparator which is connected in input to the voltage reference and to the sensor and generates in output an activation signal when the output voltage of the PNP transistor becomes smaller than the reference, a switch which is controlled by the comparator to switch off the NPN driving transistor upon the reception of the activation signal and a low-impedance circuit which is connected between the emitter and the base of the insulated vertical PNP transistor and is activated by the activation signal, in a manner suitable for bringing the insulated vertical PNP transistor practically to BV.sub.CBO.

Abstract: A series of Zener diodes (25) and an electronic power switch, such as an IGBT (18), are connected across a power supply. A circuit including a resistor (20) in series on the electronic switch, a threshold device (36, 38) connected to the resistor and a ramp generator with multiplier (40, 42, 44, 46, FIG. 2) or a thermal sensor (50, 44, 46 FIG. 3) detect the energy level dissipated in the electronic power switch when a transient occurs when the level exceeds a present value, the circuit supplies an output signal to a monostable circuit (26, 28, 48) to drive the electronic power switch with low resistance conditions for a preset time starting from the occurrence of the output signal. Another threshold device, connected to a resistor (30, 32), preferably senses the instantaneous power dissipated in the electronic switch to control the monostable circuit when the instantaneous power is higher than a preset threshold.

Abstract: Low voltage electric switchgear equipment includes a central programmer unit electrically interconnected with electronic main and branch circuit interrupters within the same enclosure and used with a multi-phase power distribution circuit. Indicating diodes are arranged on each of the circuit interrupters for signaling the occurrence of an overcurrent condition. The same indicating diodes are arranged for responding to address commands generated by the field programmer as to the exact location of each circuit interrupter within the enclosure.

Abstract: A differential protection circuit includes a pair of current transformers each having a secondary winding and each being inductively coupled to a power conductor at a different location. The secondary windings of these transformers are electrically connected in series with each other in a loop in a bucking arrangement. A resistor is connected in parallel with the secondary winding of each transformer. Control circuits are connected to sense a voltage signal appearing across the resistor and to take appropriate action when the sensed voltage reaches a predetermined level. An additional winding on one of the transformers provides isolation between the loop and one of the control circuits to prevent false tripping of the differential protection circuit.