Abstract: A method for monitoring a protective device, which has a series circuit of a multiplicity of thyristors. The protective device has a series circuit of N>1 thyristors. The series circuit is connected in a parallel circuit with an electrical device to be protected. A snubber branch is connected in parallel with each thyristor. For the purpose of testing a firing capacity, n<N thyristors in a first thyristor group are fired when a positive voltage is present across the series circuit and a negative snubber current is flowing through the snubber branches of the thyristors in the first thyristor group.

Abstract: A system for charging multiple power sources including a plurality of batteries. The system also including a plurality of diodes, each diode of the plurality of diodes electrically connected in series with at least a battery of the plurality of batteries, wherein each diode of the plurality of diodes restricts current flow into the plurality of batteries and the plurality of diodes permits current flow from the plurality of batteries. The system includes a bus element connecting the batteries in parallel, having a cross tie element having an engaged state and disengaged state. The bus element disconnects a first battery from a second battery of the plurality of when the cross-tie element is in the disengaged state, and connects the first battery to the second battery when the cross tie element is in the engaged state. The system includes a load electrically connected to the plurality of diodes.

Abstract: Systems and methods are described herein to detect an open-phase condition associated with an inverter-based resource for electric power generation within an electric power delivery system. An electric power delivery system may include one or more inverter-based resources that provide three phased electric power to one or more loads of an electric utility. A controller may include circuitry to measure voltage unbalances between different phases, high voltage sequences, phase voltage waveform harmonic distortions, voltage levels, and current levels to dependably detect an open-phase condition of the electric power delivery system.

Abstract: A power distribution system including a first power module and a second power module. The first power module including a first rectifier receiving an input power and outputting a rectified power, and a first power output configured to output the input power. The first power module further including a second power output configured to output the rectified power and a pass-through output configured to output input power. The second power module including a second rectifier receiving the input power and outputting a second rectified power, a third power output configured to output the input power, and a fourth power output configured to output the second rectified power.

Abstract: A power delivery system includes a controller, configured to receive a voltage indication signal indicating a measured voltage of a battery management system and to determine whether first and second diodes of the battery management system are faulty based on the voltage indication signal. The controller is also configured to respectively receive first and second current indication signals from first and second current sensors of the battery management system and to determine whether the first and second diodes of the first battery management system are faulty based on the first and second current indication signals.

Abstract: A DC-power system including a main DC bus, a power generating unit arranged to feed the main DC bus, an isolator switch arranged between the main DC bus and the power generating unit for isolating the power generating unit from the main DC bus in case of a main DC bus fault, a drive unit arranged to be fed by the main DC bus, wherein the drive unit includes a drive unit bus system, converter units connected to the drive unit bus system, and fuses arranged between the drive unit bus system and the converter units for protecting the converter units in case of a drive unit fault.

Abstract: A fault diagnosis method for freewheeling diodes of power converter of switched reluctance motor with two main switches per phase, in which two current sensors are arranged on a power converter with two main switches per phase, wherein, one current sensor LEM1 detects the total current of the main switches connected to the DC bus, and the other current sensor LEM2 detects the total feedback current of the freewheeling diodes connected to the DC bus. By controlling ON/OFF of the upper and lower main switch tubes, short circuit fault of the upper freewheeling diode, short circuit fault of the lower freewheeling diode, short circuit fault of both the upper freewheeling diode and the lower freewheeling diode, open circuit fault of the upper freewheeling diode, open circuit fault of the lower freewheeling diode, or open circuit fault of both the upper freewheeling diode and the lower freewheeling diode can be determined.

Abstract: Embodiments of the present invention provide cross-coupled rectifiers that use near zero-threshold transistors in a switching topology, but provide a topology that avoids reverse conduction problems. Importantly, preferred embodiment rectifiers of the invention only provide a slightly increased on-resistance in each branch, while providing both very high operating efficiency and very low turn-on voltage. An embodiment of the invention is a voltage rectifier for the conversion of RF energy into DC voltage with a turn-on threshold voltages approaching 0V.

Abstract: A motive unit, such as a generator, is disclosed. The motive unit has a fault transmitter to provide a status indication of a component of the motive unit. Failure of a component, such as a diode on the rotor of a generator, can be accordingly communicated.

Abstract: An energy harvesting circuit has an active automatic tuning circuit to search for broadcast frequencies in a band of interest and selecting only those broadcast signals received with sufficient RF strength to be used in energy harvesting. This circuit would provide power storage devices with a circuit that has a means to select the ambient RF that can maximize or enhance the performance of an RFID circuit by increasing the amount of energy for harvesting. This automatic tuning would enable a power storage devices charger circuit to move from location to location without manual tuning of the circuit and increase the effective range of an RFID circuit.

Abstract: A sensor-less technique is described for detecting the status of an AC contactor of a power inverter. In one embodiment, a method is provided of sensing an unexpected condition of an AC contactor used to couple to a power distribution system a power inverter having at least one power conductor. The method includes determining a voltage value for the conductor; determining a current value for the conductor; determining a phase difference using the voltage value and the current value; and monitoring successive values of the phase difference to produce a monitoring result. Depending on the monitoring result, a determination is made whether or not to issue an alert signal. Control routines embodying such technique may be stored on computer-readable media. A power inverter using such technique is described.

Abstract: A detection and alarm circuit includes a transformer, a rectifier, and an alarm. A first input terminal of the transformer is connected to a ground terminal of an electronic device, and a second terminal of the transformer is grounded. A first output terminal of the transformer is connected to a first input terminal of the rectifier, and a second output terminal of the transformer is connected to a second input terminal of the rectifier. A first output terminal of the rectifier is connected to a first terminal of the alarm. A second output terminal of the rectifier is connected to a second terminal of the alarm.

Abstract: Navigation of an aircraft is facilitated through the displaying on a map of an over flown region, and of the limits of zones within range of the aircraft in an emergency situation. The points of the zones within range of the aircraft are tagged on the basis of: an estimate of the vertical margins to reach these points, taking into account non-maneuverability zones neighboring the aircraft to be circumvented; a vertical flight profile to be complied with; and a safety height margin.

Abstract: The present disclosure provides a power rectifier for a Radio Frequency Identification tag circuit. The power rectifier can be constructed from serially coupled rectifier stages. One of the rectifier stages includes a backflow reduction device or a bias preservation circuit, or both, at least one of which us controlled by a signal derived from a control signal source of the tag circuit.

Abstract: A system and method for generating a rectified signal in a RFID tag. An alternating signal is received by the RFID tag, and a first phase of the alternating signal is coupled to a gate and to a first non-controlling terminal of a first switching transistor. The non-controlling terminal of the first switching transistor is one of a source and a drain of the first switching transistor. A first bias voltage is applied between the first non-controlling terminal and the first gate of the first switching transistor and a rectified voltage is received between the first non-controlling terminal and a second non-controlling terminal of the first switching transistor.

Abstract: A power converter including a processor, at least one component whose health in the power converter will degrade over time, and at least one alarm is disclosed. The processor is configured for monitoring the health of the component over time, and for activating the alarm when the monitored health of the component reaches a threshold level.

Abstract: Disclosed is a rectifier for supplying double voltage and an RFID tag thereof. The rectifier includes a charging part for charging an input voltage induced to input ends by a received radio frequency (RF) signal; a power provider for charging a sum voltage corresponding to the sum of the input voltage induced to the input end and the voltage charged in the charging part as a power voltage, and discharging the charged power voltage to provide a direct current (DC) power; and a switching part for switching to supply the input voltage induced at the input ends to the charging part during a first interval and switching to supply the sum voltage to the power provider during a second interval. Accordingly, double voltage can be supplied to other electric elements formed in the RFID tag and overcurrent caused by overvoltage can be prevented from flowing into the elements.

Abstract: An inductive powering device provides power to a portable device via inductive coupling between primary coils in the surface of the powering device and a secondary coil in the portable device. The portable device includes a passive locator device, such as an RFID device, to allow the primary coils of the inductive powering surface to detect the presence and location of the secondary coil, and only primary coils adjacent the secondary coil are energized for power transfer. A cost-effective driving configuration that arranges the primary coils into a matrix with drive circuits switchably connected to the row and columns is used to energize the primary coils.

Abstract: A system and method for testing a cathodic protection system includes a cathodic protection rectifier configured to apply a voltage across a pipeline and a reference point. The method includes measuring a magnitude of an output voltage of the cathodic protection rectifier, transmitting to a site remote from the rectifier, the measured output voltage magnitude using a cellular control channel, receiving the transmitted measurement at the remote site, and using the transmitted measurement to determine whether the cathodic protection system is operational.

Abstract: The defective power source detecting apparatus of a power source supply system has: an output voltage monitoring circuit 16-1 to 16-N for monitoring the DC voltage on an output end of the rectifier circuit which is an output end of each power source apparatus, and for outputting a defect detecting signal to show that the defective state occurs, when the output of the rectifier circuit is abnormal; an inverter output monitoring circuit 18-1 to 18-N for monitoring an inverter output of each power supply apparatus, and for outputting a defect detecting signal to show that the defective state occurs, when the output of the inverter is abnormal; and a control circuit 50 for fetching the monitoring outputs of the output voltage monitoring means and the inverter output monitoring means, and for judging the power source apparatus corresponding to the case in which the outputs of the rectifier circuit and the inverter are abnormal, to be defective.

Abstract: The present invention provides a digital automatic power interruption and re-supply relay for performing detection and comparing operation to inform a state of an accident with voice and numerals and automatically operating a connected relay to interrupt power when there occur abnormal changes such as interruption of electric power, open-phase, anomalous voltage, unbalanced voltage, negative-phase, overcurrent, and electric leakage in a power transmit and supply line of high and low voltage or special high voltage and high (low) voltage and, after compensating for the accident, for automatically re-supplying the power.

Abstract: A system for monitoring and alternatively adjusting the electrical energy input and output of remotely located corrosion protection rectifiers on a section of a longer pipeline includes three elements. The first element is a monitoring unit which monitors electrical input, output voltage, output amperage and level of applied cathodic protection of the electrical energy provided to the pipeline by a rectifier. This data on electrical energy is then transmitted to the second element, a low-level communication satellite. The low-level communication satellite then retransmits the data to the third element, a management data center. The information received at the management data center may be monitored, recorded or transformed into adjustment signals which are then retransmitted via the low-level communication satellite back to the rectifier on the pipeline.

Abstract: A portable electronic test instrument is adapted for the automatic testing of semiconductor diodes regardless of the orientation of the diode relative to the test probes. The test instrument supplies an a.c. sine wave test voltage coupled to the test probes. The maximum negative voltage and the maximum positive voltage are measured and compared against a set of predetermined open and short circuit values to obtain a decision of open, short, or ok for each value. The combination of the two comparisons is used to determine the device status according to a decision criteria. The diode status is accordingly displayed on the graphical display of the test instrument, indicating the device is open, shorted, a diode with a forward orientation or a reverse orientation with respect to the test probes, or of an unknown type. The diode forward bias junction voltage is displayed regardless of its orientation.

Abstract: A method for testing a power bridge for an electric vehicle propulsion system, the power bridge including a switching circuit having first and second switching elements operable between "on" and "off" states. The method comprises the steps of selectively switching the first and second switching elements between the "on" and "off" states, monitoring the first and second switching elements to determine whether the first and second switching elements operate between the "on" and "off" states when selectively switched, and indicating a failure o#the switching circuit when at least one of the first and second switching elements does not operate between the "on" and "off" states when selectively switched.

Abstract: An electronic circuit senses that at least one circuit of rectifying diodes has been opened and response initiates an alarm. To sense one of the diode circuits being opened, the electronic circuit detects a temporary crossing of a low threshold by a DC voltage supplied at the rectifier output. The circuit is particularly applicable to high-power transformer-rectifiers aboard aircraft.

Abstract: In a triac power switching system, two triacs are connected in series between an AC power source and a load. Each time power is applied to a load, the triacs are tested by first turning on one of the triacs while maintaining the other triac turned off, then turning on both triacs to apply power to the load for a set time interval and then turning off one of the triacs and determining whether power is still applied to the load. If power is applied to the load while either one of the triacs is supposed to be off, an alarm is sounded. In addition, if power is not applied to the load when both triacs are turned on, an alarm is sounded.

Abstract: An apparatus and method are disclosed for measuring and displaying the percentage of ac voltage ripple present on a direct current input voltage. In addition, the apparatus can be set to activate alarms and trip relays when the percentage of ac voltage ripple meets or exceeds a preset value.

Abstract: A visual indication system for easily providing information about the status of the output terminals of a solid state relay. A two-electrode neon glow lamp is connected across the output terminals of the relay in series with a current limiting resistor. The shunting impedance of the relay output terminals prevents voltage from inducing a glow in the neon lamp in certain modes of terminal configuration. When the terminals are ON, neither electrode glows. When the terminals are OFF, both electrodes glow. If the AC relay fails in a half-wave mode, only one of the electrodes will glow.

Abstract: A driver circuit for the coil in relay contains a suppressor diode across the coil terminals. Two light-emitting diodes are connected in reverse polarity so that one diode operates when the coil is energized and the other diode operates if there is current flowing in the reverse direction when the suppressor diode fails to clamp the coil voltage. The diodes may be of different colors and may be positioned close to each other to produce the composite color when they are energized at the same time or in rapid succession.

Abstract: An electrical apparatus for monitoring electrical continuity includes a number of input circuits each associated with a respective arm of a multi-phase rectifier circuit the continuity of which is to be monitored. Each input circuit includes a comparator which generates a train of pulses P while an input current persists in the arm. If a discontinuity arises in an arm for a first preset interval of time a monostable in that arm generates a first trigger signal. If the discontinuity persists for a further preset interval of time another monostable, common to all the arms, triggers an alarm via a bistable circuit.

Abstract: A device for failure detection in series-connected semiconductor rectifiers (1) comprises transformers (2) whose number is equal to that of the rectifiers (1) and which comprise input windings (3), supply windings (6), and additional parallel-connected windings (9), RC-circuits whose number is equal to that of the rectifiers (1), having resistors (4) and capacitors (5), and also a pulse generator (7), and a measuring element (8).The input winding (3) of each transformer (2) has one lead-out thereof connected to a cathode of the respective rectifier (1), and another lead-out to the capacitor (5) of the respective RC-circuit. The resistors (4) of each RC-circuit are connected to the anodes of each rectifier (1). The supply windings (6) of the transformers (2) are connected to one another in series and connected by one terminal to the first lead-out of the pulse generator (7).

Abstract: A circuit arrangement for monitoring a thyristor comprising an auxiliary thyristor disposed between the anode terminal and gate terminal the thyristor, and a signal generator device which contains a light-emitting diode for sending light signals to an evaluating device. In order to obtain a particularly simple and therefore functionally reliable design of the circuit arrangement, due to the elimination of a separate energy supply circuit, and to achieve emission of light signals with a particularly high light output, the signal generator device has a first pair of input terminals coupled in series with the auxiliary thyristor and the light-emitting diode is arranged between the input terminals of the signal generator device.

Abstract: An electronic switch with CSE wiring, especially a triac, has a load connected in series therewith to an a-c voltage network. A rectifier bridge circuit has its a-c terminals connected into the driving circuit of the electronic switch. The d-c terminals of the bridge circuit are connected to a light-emitting diode poled in the conduction direction. Since the firing current for the switch is periodically repeated, the light-emitting diode indicates the switching state of the triac since the brief pauses without current of the LED are not perceived by the human eye.

Abstract: An automated SCR cell test exercises each of the twelve SCRs in a dual, 3 phase, full wave SCR rectifier bridge singly to detect shorted SCRs and in pairs to detect open SCRs or faulty gate circuits.

Abstract: A gate-turn-off thyristor failure detecting circuit includes a detector which detects an off-gate signal for a gate-turn-off thyristor and a current level detector which compares the signal with a predetermined value and produces an output signal indicative of the failure of the gate-turn-off thyristor.

Abstract: In a power converter switching system, the instantaneous blocking ability of semiconductor switching elements is determined by monitoring the reverse blocking ability of a control junction in each switching device. A gate firing circuit applies negative turn-off drive to the control junction. The control junction impedance is monitored and switch recovery is indicated by a change in the magnitude of the impedance. A switch recovery logic signal is then generated and used to initiate the firing of the next successive switch element. When switches are combined in multipulse groups, the recovery signals may be logically combined to provide proper switching coordination, emergency protection and diagnostic information.

Abstract: A tester for telephones and telephone answering systems features a dialing test capability for high speed dialing systems by providing the dialed digits in a single display element serially in time at a delayed rate set by strobing the digits from a memory storage element. A two-level ringing signal is provided to test for marginal telephone bell sensitivity. Means are further provided for reversing the emulation of the central office battery polarity so as to test for diode failure in electronic telephones. A simple cord circuit test for open- and short-circuit in the wall and handset cords, and moreover provides for detection of connector wiring reversal. Precision long-duration ringing burst capability is provided, along with ringback, dial tone, cut-out, and two-way communication between a telephone answering system under tests and a supplemental telephone as to provide for complete testing of the various phases of actuation of automatic answering systems.

Abstract: A diode failure detecting device in a rotary rectifier having fuses provided respectively for phases and connected in series to rectifying diodes. Light emitting diode circuits in one embodiment are connected in parallel respectively to the fuses which are arranged on the peripheral surface of a rotor. The LED's preferably emit light in different emission spectra when the respective fuses are blown out. An optical fiber sensor is provided on the side of a stator, for detecting when the LED's emit light and a photo-electric converter converts optical signals applied thereto through the optical fiber sensor into electrical signals through optical spectral discrimination separately according to the phases of the rectifier. A logic circuit determines the flow of over-current in the rectifying diodes from an output of the photo-electric converter. In a second embodiment, flags on the fuses are optically scanned to determine the presence of a blow fuse.

Abstract: A circuit for detecting the occurrence of a shorted diode in the rotating rectifier of a brushless alternator. A sensing circuit is responsive to the direction of current flow through the exciter field winding. A reversal of the current indicates that there is a shorted rectifier diode.

Abstract: An arrangement for checking the integrity and operability of a semiconductive device including a control circuit for injecting test signals into a normal control signal to induce a momentary change of the operating condition of the semiconductive device, a sensing circuit connected in parallel with the semiconductive device sensitive to an induced change to produce an output indicating the induced change, and a correlation circuit operative to correlate the test pulses with the sensed response which is arranged to carry out predetermined action in the event that the correlation circuit determines a state of inoperability of the semiconductive device.

Abstract: A method and apparatus for use in conjunction with a power conversion system employing a plurality of switching elements for controlling the electrical power supplied to a load from a source includes the sensing of the instantaneous voltage furnished to the load and providing a signal representing the time derivative of the sensed voltage. The derivative signal thus developed is compared with predetermined reference values to develop output signals which are logically combined to provide a final signal representative of the instant in time at which one of the switching elements is commutated (turned off).

Abstract: A device for monitoring thyristors of a high-voltage valve comprises thyristor voltage detectors coupled via light guides to a buffer storage unit through a selector. Also provided are an OR gate assembly, an adder, a memory unit, and a comparison unit, which are placed in series and coupled to a control unit. The OR gate assembly is connected to the buffer storage unit which is also coupled to the control unit. A second input of the comparison unit is connected to a second output of the adder, while its output is connected to an indicator signalling the quantity of disabled thyristors and to a unit protecting the high-voltage valve against breakdown. The selector is also connected to an indicator signalling the numbers of disabled thyristors.

Abstract: A snubber circuit coupled across each thyristor to be gated in a chain of thyristors determines the critical output of a NOR LATCH whenever one snubber circuit could not be charged and discharged under normal gating conditions because of a short failure.

Abstract: A programmable controller (41) based logic system places two electronic output converters (14,18) in series for redundant protection against the inadvertent energization, due to the failure of an image register (66,68) or due to the shorted failure of a triac (10,12) on the output converters (14,18), of an energize-to-start, deenergize-to-stop field device (28). A control and monitor circuit monitors the image registers (66,68) and the output converter (14,18) triacs (10,12) that switch power on and off to the field device (28) to assure that the triacs (10,12) have not failed in an unsafe mode or that the image registers (66,68) have not failed. The monitor circuit continuously monitors both image registers (66,68), the first triac (10) and the series combination of the two triacs (10,12). The monitor circuit intermittently monitors the second image register (66) and the second triac (12). A failure of either or both triacs (10,12) or either or both image registers (66,68) energizes an alarm.

Abstract: Each power diode in an ORed direct-current power distribution system has connected thereacross, between the respective load and source terminals of the power diode, a series connection of respective first and second light-emitting diodes (LEDs) with the LEDs being similarly poled with respect to their common connection, with the power diode and the first LED being oppositely poled with respect to the power diode load terminal, with a resistance connected between the common LED connection and the power supply return. A resistance-LED arrangement is also provided in parallel with each nonindicating fuse. The ON (fully conducting--showing detectable visible light) and OFF (not fully conducting--not showing detectable visible light) patterns of the LEDs, both under the condition of normal voltage on each power bus and under the condition where the relative voltage between buses is varied slightly, can be used for circuit failure diagnostics.

Abstract: To provide a visible output indication, for example by an indicator light on a controller supervisory panel of the vehicle, of proper functioning of the voltage regulator power transistor, monitoring circuits are provided which sense the electrical condition of current flow through or the voltage condition of the field winding or output bus respectively by including a light emitting diode (LED) in an indicator circuit, for example by connecting it in series to the coupling resistor. In one form, a Zener diode Z (FIG. 1) is connected across the output bus with the LED in series, so that the LED will light if the output bus reaches a voltage which might damage the battery, for example due to short circuit or alloying-through of the output transistor T of the voltage regulator; in another form, an LED which preferably is green, LDg (FIG.

Abstract: Each arm forming a three-phase full wave rectifier bridge includes a semiconductor diode, a current transformer and a fuse. The current transformer is connected to a pulse extinction indicator circuit through a pulse transformer. When no current flows through the arm for a predetermined time or more, the pulse extinction detection circuit produces a DC signal indicating the blowing of the fuse. The rectifier bridge, the current transformers, the fuses and the pulse extinction detection circuit are all disposed on the rotor of a brushless synchronous machine.

Abstract: First and second diodes are formed on the same semiconductor substrate. Both the diodes are forward biased by a direct current power supply. An attenuator is connected to a positive terminal of the first diode to produce an output lower in level than a voltage on the positive terminal of the first diode. A comparator receives the output of the attenuator as a first input and a voltage on a positive terminal of said second diode as a second input. When the first input is smaller than the second input, the comparator produces an output "0." When the first diode is open-circuited and the first input becomes greater than the second input, the comparator produces an output "1" and detects the fault of the first diode.

Abstract: A rectifier unit for supplying power to a D.C. load including a transformer having a primary, a secondary and a saturable core, the secondary defining an output section and a control section. A ferroresonance control circuit simulates saturation of the transformer core and includes an electronic switch for controlling the degree of simulated core saturation and thereby regulating the rectifier unit output. Rectifier failure alarm circuitry produces a failure alarm in response to a number of rectifier unit malfunctions. The rectifier failure alarm circuitry is coupled to the ferroresonance control circuitry and comprises a rectifier alarm element operable between the first condition wherein a rectifier failure alarm is produced and a second condition. The failure alarm element is operated from its first condition when the electronic switch minimizes the rectifier system output.

Abstract: A monitoring device for semiconductor rectifiers which are located in a three-phase current bridge circuit, in which the bridge circuit is provided with two semiconductor rectifiers per rectifier branch, including a current-sensitive detector circuit connected to each pair of semiconductor rectifiers of each branch through a resistor, wherein when the semiconductor rectifiers are intact, the sum of all current flowing through the resistors is zero, as detected by the current-sensitive detector circuit.