Abstract: Lightning strike protection system for aircraft fuel tanks made of low electrical conductivity composite material. The system comprises an electrical conductive thin wire mesh (1) that covers the whole external surface of the tank outer skin (I) made of composite and a thick wire metallic mesh (2) overlapping the mesh (1) at a minimum distance of 50 mm to both sides of a row of fasteners (III) joining the said outer skin (I) to one internal part (II) of either composite or metallic material. Both metallic meshes (1, 2) maintain electrical contact by their installation/assembly and by means of metallic countersunk head washers (3) connected to bonding points and set to the gap existing between the fastener (III) and the outer skin (I). The corresponding fabrication process is also described.

Abstract: A surge suppressor module includes a power conductor, a ground conductor, and a housing including an opening and a plurality of dovetail groove mechanisms and arcuate ground bus bars for electrically and mechanically mounting a corresponding surge suppressor module. An alternating current surge suppressor circuit is housed by the housing. The circuit receives the power and ground conductors through the opening of the housing. The circuit electrically connects the ground conductor to the plurality of arcuate ground bus bars for electrically and mechanically mounting a corresponding surge suppressor module, in order to provide a common ground connection thereto.

Abstract: An electronic filter for filtering the output signal of a current sensor of a circuit breaker is disclosed. The current sensor has an output signal characteristic similar to that of a Rogowski coil output signal characteristic that includes a third harmonic noise component in response to a switching primary current of the circuit breaker, and the circuit breaker has an electronic trip unit with an instantaneous pick-up setting responsive to the output signal of the current sensor. The electronic filter includes a first stage and a second stage. The first stage has a first transfer function that defines first characteristic poles and permits passage of the third harmonic noise component. The second stage has a second transfer function that defines second characteristic poles and filters the third harmonic noise component.

Abstract: A signaling system for detecting power line discontinuity in a power distribution system having a local power generator in a feeder line employs a signal generator that provides a local generator control signal with a preset protocol continuously and is located in the power distribution system upstream of said local power generator. A power detector terminates the local generator control signal and a signal detector in said feeder line detects the presence of the signal and triggers the shutdown of the local generator when the signal is not detected by the signal detector for a predefined period of time.

Abstract: A solid-state relay/breaker that can replace mechanical units to control any type of AC or DC load. Power MOSFETs or other transistors control a load current. A bypass current sensing path monitors MOSFET current and causes a shutdown through signal processing in the event of an over-current condition. This shutdown resembles that of a slow-blow fuse where the rate of shutdown is proportional to the value of the current. This prevents shutdown on momentary spikes or in-rush. In addition, temperature and internal power supply voltages are monitored to determine additional operational conditions where over-temperature or voltages out of range can also cause shutdown. The MOSFET and current sensing path are turned on and off in staggered timing with different slew rates to provide built-in hysteresis. The device can be manufactured in any type of package to match any type of environment or existing replacement requirement.

Abstract: A method and system for providing protection for a superconducting electrical cable located in a utility power network includes detecting a fault current on the superconducting electric cable, determining the cumulative total energy dissipated in the superconducting electrical cable from the fault current and at least one prior fault current over a predetermined time period, and determining whether to disconnect the superconducting electrical cable from the utility power network on the basis of the cumulative total energy dissipated.

Abstract: A fan system is provided which keeps a record of the electric connection between a battery ECU and an accessory battery and starts a fan if it is determined based on the record that the electric connection between the battery ECU and the accessory battery was just in an unconnected state.

Abstract: The car power source apparatus switches a pair of contactors (driving battery relays) connected to positive and negative output sides of a driving battery via a switching circuit with an auxiliary battery as power supply. The switching circuit is provided with a voltage detection circuit to detect auxiliary battery voltage, a series switching circuit to connect coils of the pair of contactors in series and switch both contactor contacts on, and a parallel switching circuit to connect coils of the pair of contactors in parallel and switch both contactor contacts on. When auxiliary battery voltage is higher than a set voltage, it connects the pair of contactor coils in series to switch the contacts on via the series switching circuit, and when auxiliary battery voltage is lower than a set voltage, it connects the pair of contactor coils in parallel to switch the contacts on via the parallel switching circuit.

Abstract: A switch for switching off at least one airbag having two identical sensors for detecting a switching state of the switch is provided, the two identical sensors being connected up in such a way that the electrical characteristic-quantity ranges to be evaluated for detecting the switching state differ from each other. This is achieved with the aid of different resistor networks between the two sensors and a signal evaluation unit.

Abstract: A rail clamp circuit (100) includes first and second power supply voltage rails, a multiple independent gate field effect transistor (MIGFET) (128), and an ESD event detector circuit (138). The MIGFET (128) has a source/drain path coupled between the first (112) and second (114) power supply voltage rails, and first and second gates. The ESD event detector circuit (138) is coupled between the first (112) and second (114) power supply voltage rails, and has first and second output terminals respectively coupled to the first and second gates of the MIGFET. In response to an electrostatic discharge (ESD) event between the first (112) and second (114) power supply voltage rails, the ESD event detector circuit (138) provides a voltage to the second gate to lower an absolute threshold voltage of the MIGFET (128) while providing a voltage to the first gate above the absolute threshold voltage so lowered, thereby making the MIGFET (128) conductive with relatively high conductivity.

Abstract: A protection scheme to protect pulse width modulated drives is described. The scheme is implantable in both hardware and software and combinations thereof. The semiconductor devices of the drive are protected from transient signals such as power line spikes and loss of line. The present scheme uses an adaptive technique to determine the normal or steady state distortion (transients and harmonics) value in an unfiltered power signal. The present distortion value is compared to the normal distortion. If the present distortion exceeds the steady state value by a given amount, then the drive is placed in freewheel mode to protect the semiconductor devices in the drive.

Abstract: Systems and methods for generating a high voltage pulse. A series of voltage cells are connected such that charging capacitors can be charged in parallel and discharged in series. Each cell includes a main switch and a return switch. When the main switches are turned on, the capacitors in the cells are in series and discharge. When the main switches are turned off and the return switches are turned on, the capacitors charge in parallel. One or more of the cells can be inactive without preventing a pulse from being generated. The amplitude, duration, rise time, and fall time can be controlled with the voltage cells. Each voltage cell also includes a balance network to match the stray capacitance seen by each voltage cell.

Abstract: A voltage stabilizing and surge preventing vehicle grounding system is essentially constructed of a surge absorber, a surge suppresser, and a multi-tapped closed loop grounding wire. The positive terminal of the surge absorber is connected to a first conductor of the surge suppresser, whereas the negative terminal of the surge absorber is connected to the negative terminal of the vehicle generator. A second conductor of the surge suppresser is connected to the positive terminal of the vehicle generator so as to stabilize the output voltage of the generator and prevent the impulse surge from the generator.

Abstract: A two channel universal device for advanced protection from a short circuit current which evaluates a rate-of-change of current in a supply feeder and compares the current in the supply feeder and the current in load phases generating a differential signal in such a way that in normal conditions, when the load is running or starting, the differential signal is virtually zero. The differential signal and the rate-of-change of current in the supply feeder are compared with the settings of the protective device. If both the value of the rate-of-change of current and the value of the differential signal simultaneously exceed their settings, after an adjustable time delay, the device produces a signal to open the circuit. The existence of two conditions necessary to initiate the trip signal to cause the circuit to open ensures the reliable operation of this device and provides a feasible fast protection scheme.

Abstract: An acoustic fluid machine includes an acoustic resonator, a valve device, a piston, and an actuator. The acoustic resonator has a larger-diameter base and a smaller-diameter upper end. The valve device is provided on the upper end of the acoustic resonator and has a sucking hole and a discharge hole. The piston is provided in the base of the acoustic resonator and has a surface such that the distance between the upper end of the acoustic resonator and the upper surface of the piston is substantially constant over the whole surface of the piston. The actuator is connected to the piston and reciprocates the piston at high speed axially with a very small amplitude so that a gas is sucked into the acoustic resonator via the sucking hole and discharged via the discharge hole by virtue of pressure fluctuations within the acoustic resonator.

Abstract: A ground-fault circuit-interrupter method and system for three-phase electrical power systems including a plurality of GFCI units and a processor forming a ground-fault circuit interrupting system for use in a three-phase power distribution network including a three-phase source of electrical power, a three- or four-wire main circuit, and a plurality of three- or four-wire feeder circuits connected across the main circuit. A GFCI unit is provided in the main circuit and in each of the feeder circuits. The processor is programmed to continuously monitor the main GFCI unit and each feeder GFCI unit to determine when and where a fault has occurred and, in response thereto, to interrupt the faulted circuit and to inhibit tripping of the non-faulted circuits. The novel GFCI system is applicable for solidly-grounded, resistance-grounded, or ungrounded as well as other three-phase systems.

Abstract: A control system for a vehicle power supply for supplying power to a predetermined power receiving portion includes a first power generating power supply portion, second power generating power supply portion, and controller. The controller is arranged to set the voltage to be output to the power receiving portion from one of the power generating power supply portions in accordance with the output voltage of the other of the power generating power supply portions. With this arrangement, the power receiving portion is prevented from being supplied with an excessive amount of power, and when power regeneration is being performed by the second power generating power supply portion, the regenerated power is effectively used. Thus, the fuel economy of the vehicle can be increased.

Abstract: An apparatus for electronically switching a detonation device is configured to arm an energy source upon receiving a first signal and discharge the energy source to the detonation device upon receiving and validating a second signal. An explosive device comprising a detonation device electrically coupled to an electronic switching device is also provided, wherein the switching device comprises a microcontroller configured to validate the first signal and the second signal. The detonation device may comprise a semiconductor bridge device configured to activate the explosive device upon receiving a charge across a first terminal and a second terminal from the switching device. Methods of operation are also disclosed.

Abstract: The present invention is to provide an improved surge protector device. The present invention's surge protector device basically has a plurality of metal bars which are combined to a single body by a continuous high-resistive film of semiconductor crystal so that there is no gap between adjacent metal bars; and electrodes formed on the endmembers of the said metal bars composing the single body. Thus, the present invention's surge protector device is fabricated so as to have no air gap between adjacent ones of the metal bars. As a result, the present invention's protector device can operate in such a way that the surge protector device changes from a non-conductive state to a conductive state due to breakdown in depletion region accompanying the semiconductor crystal when the voltage across the electrodes exceeds a threshold voltage because of a surge.

Abstract: A thermal shutdown circuit for protecting a main FET that conducts a load current ILOAD. A reference circuit provides a temperature current proportional to temperature. A thermal sensor circuit has a resistor and generates an output signal signaling thermal shutdown when the voltage generated across the resistor by the temperature current exceeds a predetermined value. A sense FET having a size smaller than the main FET conducts a sense current ISENSE proportionately smaller than ILOAD. A current mirror mirrors a scaled current proportional to ISENSE to be conducted through the resistor, the scaled current being scaled so as to cause the voltage generated across the resistor to exceed the predetermined value when ILOAD exceeds a predetermined value.