Abstract: A buffer circuit having enhanced overvoltage protection includes core buffer circuitry couplable to a first voltage source having a first voltage level. The core buffer circuitry is configured to receive a first signal and to generate a second signal which is a function of the first signal. The buffer circuit further includes a protection circuit coupled between the core buffer circuitry and a signal pad. The protection circuit is operative: (i) to clamp the first signal to about the first voltage level when a third signal received at the signal pad exceeds the first voltage level by a first amount; and (ii) to generate the first signal being substantially equal to the third signal when the third signal is less than or substantially equal to the first voltage level.

Abstract: A phase shift procedure for detecting a disconnect of a power grid from a feeder that is connected to a load and a distributed generator. The phase shift procedure compares a current phase shift of the output voltage of the distributed generator with a predetermined threshold and if greater, a command is issued for a disconnect of the distributed generator from the feeder. To extend the range of detection, the phase shift procedure is used when a power mismatch between the distributed generator and the load exceeds a threshold and either or both of an under/over frequency procedure and an under/over voltage procedure is used when any power mismatch does not exceed the threshold.

Abstract: The present invention is directed to a protective device including a plurality of line terminals and a plurality of load terminals configured to be connected to at least one load. A test circuit is coupled to the plurality of line terminals and the plurality of load terminals. The test circuit is configured to generate a simulated fault signal to the fault detection circuit in response to a user stimulus. A fault detection circuit is coupled to the plurality of line terminals and the plurality of load terminals. The fault detection circuit is configured to detect at least one fault condition. The at least one fault condition includes the simulated fault signal. A circuit interrupter assembly is coupled to the fault detection circuit. The circuit interrupter assembly includes a set of movable contacts configured to open in response to the fault detection circuit in a tripped state. The plurality of line terminals are decoupled from the plurality of load terminals.

Abstract: In an electric power switching apparatus a control circuit generates a switching control signal, for controlling successive current switching operations, as a of succession of pulse period patterns with each pulse period pattern made up of one or more successive pulses each having an identical pulse period, and with successive pulse period patterns constituting the control signal having respectively different values of pulse period. The noise power of high-frequency components resulting from the current switching is thereby dispersed along the frequency spectrum, reducing resultant radio noise interference.

Abstract: A symmetrical power system is provided that supplies a symmetrical power at an output power supply. The symmetrical power system comprises a first transformer and a second transformer which have identical transformer properties. The first and second transformers are each separately in communication with one of a first and second phase of an input power supply via corresponding first primary windings, and each separately in communication with one of a first and second phase of the output power supply via corresponding first secondary windings. The first and second transformers are connected in parallel between a input common conductor of the input power supply via corresponding second primary windings and an output common conductor connected the output power supply via corresponding second secondary windings. The first and second phases of the output power supply are inversely phased.

Abstract: Provided is an apparatus and method for providing to a differential relay an operational vector-group compensation setting pair that automatically provides correction for a phase shift occurring between currents of at least two windings of a power transformer. The method includes calculating a first and second plurality of phasors using secondary currents derived from respective first and second winding of the at least two windings. The method also includes selecting one pair of vector-group compensation settings based on operate current values calculated using different pair combinations of the vector-group compensation settings applied to the first and second plurality of phasors.

Abstract: A power redundant power system and a method for controlling the power system are presented, wherein the power system is composed of at least one inverter for supplying AC power to a load through a bus, a phase lock system to synchronize all output voltages of the inverters and a current sharing circuit to properly distribute the load current among all inverters. Each inverter is controlled by an unbalanced power to limit the increase of its cross current. Moreover, the information related to DC bus voltage is further applied to control the inverters, whereby the cross current is mitigated and entire power system is operated steadily.

Abstract: An interrupter circuit is disclosed for interrupting power in a power cable from a power source. The power cable comprises an insulated line wire and an insulated neutral wire with a conductive shield surrounding the line wire and the neutral wire. A non-insulated drain wire contacts the conductive shield. An outer insulating layer is molded about the conductive shield. A disconnect switch is interposed between the power source and the power cable with a disconnect switch driver controlling the disconnect switch. A sensing circuit is connected between the drain wire and the disconnect switch driver for sensing a leakage current between the conductive shield and one of the insulated line wire and the insulated neutral wire for opening the disconnect switch for disconnecting the power cable from the power source.

Abstract: A propellant anti-theft system can not only perform permission/stop of operation of a vehicle in a simple and easy manner without using a key, but also suppress the theft and reuse of vehicle parts. The system includes a portable device and an on-board device installed on the vehicle, and further includes an engine control device, a switch and various units, all of which are connected to the on-board device. The on-board device includes a transmitter receiver, a storage circuit and a control circuit. The portable device includes a transmitter receiver, a storage circuit and a control circuit. The control circuit of the on-board device compares common data possessed by itself and common data stored in microprocessor units of the engine control device and the various units, and unlocks a steering locking section included in the various units and outputs an engine starting permission signal to the engine control device when both of the individual pieces of common data coincide with each other.

Abstract: An apparatus for protecting electronic equipment from voltage surges includes a network interface coupled to a computer device for connecting the computer device to a computer network and a discrete voltage surge protection device coupled to the computer network with a first unshielded cable and to the network interface with a second unshielded cable. The unshielded cable comprises at least one wire pair and the discrete protection device comprises a voltage suppressor device coupled between the wires of each wire pair. The discrete voltage surge protection device renders the apparatus compliant with the Telcordia (Bellcore) GR-1089-CORE Intrabuilding Lightning Surge Tests.

Abstract: In a RAID system, the power supplied to hard disks (HDDs) can be increased, and a plurality of types of HDDs can be installed. A plurality of HDD packs 33 are supplied with a single high voltage from a motherboard 28. The HDD packs 33 each accommodate, in a canister, an HDD 107, 181, 185 or 187 with different power supply specifications or communication interface specifications, as well as a DC/DC converter 109 to convert the power supply. Part of the HDD packs 33 have a data transfer interface conversion circuit 195 as well.

Abstract: The present invention constructs a flexible power supply backup system corresponding to electronic devices (apparatuses) at low cost, and realizes reliable operation of the apparatuses. There is provided a power controller 1 that controls power of an apparatus 100 provided with a backup power supply for power supply, which includes a power failure state determination unit 21 that determines the power failure state of the power supply, a power supply installation state determination unit 22 that determines the installation state of the backup power supplies 3, 7, etc. installed in the apparatus 100, and a power control unit 23 that, in case the power failure state is determined by the power failure state determination unit 21, controls power using the backup power supply based on determination result by the power failure state determination unit 21 and determination result by the power supply installation state determination unit 22.

Abstract: By switching the NMOS (11) on and off, a drive current passes through a solenoid (15). The drive current passes through a conversion circuit (16), and an amplifier circuit (17) outputs a current detection result by amplifying the output voltage of the conversion circuit (16). Because a plurality of resistor elements (161 to 16n) that constitute the conversion circuit (16), together with elements that constitute the amplifier circuit (17) are formed diffused to a semiconductor substrate (100), even if the attribute changes by the conversion circuit (16) generating heat, by the drive current, the amplifier circuit (17) becomes approximately the same temperature, and the attribute changes. Therefore, a highly accurate current detection becomes possible without using components for temperature correction.

Abstract: A self-contained current sensor unit is integrated with a standard circuit breaker as an attachment to the circuit breaker that requires minimal modification of the circuit breaker and that becomes an extension of the case of the circuit breaker. The current sensor unit includes a magnetic structure with a programmable Hall Effect device and may include a power supply, a Hall Effect voltage regulator, and an output signal conditioner.

Abstract: The present invention relates to combination control systems employing at least one intermediate module between different control modules and, in one embodiment, relates to a system for isolating a load from multiple power sources. The system includes a first power isolation system capable of receiving a first power from a first input port and determining whether the first power is communicated to a first output port, and a second power isolation system capable of receiving a second power from a second input port and determining whether the second power is communicated to a second output port. The system further includes an intermediate module connected with the first and second power isolation systems, where the intermediate module allows for at least one intermediate control signal to be provided to both of the power isolation systems.

Abstract: An apparatus to correct the driving power of an actuator in a vehicle includes a comparator that compares a battery voltage of the vehicle with a predetermined reference voltage. A controller adjusts and outputs a duty ratio of a Pulse Width Modulation (PWM) signal according to the compared result of the battery voltage and reference voltage. A switching element is switched on and off by the PWM signal and outputs the battery voltage after a transformation. An actuator operates by receiving the transformed battery voltage through the switching element. The actuator operates at a constant speed regardless of the variation of the battery voltage.

Abstract: A security apparatus is installed in a vehicle including a door-lock control device for performing a door lock control on the basis of a signal transmitted from a portable transmitter, which a legitimate driver should take along. The security apparatus prevents a theft of the vehicle. The security apparatus includes a receiving circuit, an antenna, and a control circuit. The receiving circuit can receive the signal transmitted from the portable transmitter. The control circuit has a function of switching a security mode on the basis of a reception state of the receiving circuit and a member relating to the door lock control such as a door lock motor.

Abstract: A control circuit for a power supply circuit that selects an appropriate power source to continuously supply power. The control circuit includes a power synthesizing circuit for generating synthesized power by synthesizing a first power supplied from a regulator and a second power supplied from a regulator, or battery power and bus power, so that each circuit of the control circuit is operated by the synthesized power. Operation of the control circuit is enabled even if the supply of one power is stopped. The first switch device and the second switch device are controlled to select the appropriate power source in accordance with the currently supplied power so that power is continuously supplied.

Abstract: A circuit system is disclosed for protecting a capacitor coupled between a voltage supply node and a complementary voltage supply node from an ESD. The circuit system includes at least one NMOS transistor having a drain coupled to the voltage supply node, a source and a gate together coupled to the complementary voltage supply node, and at least one diode chain having one or more diodes serially coupled between the voltage supply node and the complementary voltage supply node. During an ESD event, the diode chain and the NMOS transistor dissipate an ESD current from the voltage supply node to the complementary voltage supply node, thereby protecting the capacitor from ESD induced damages.

Abstract: The invention discloses an integrated circuit that includes a first device in a first power domain; a second device in a second power domain; and an electrostatic discharge (ESD) bus coupled to the first and second devices for providing a current path to dissipate an ESD current during an ESD event occurring at the first or second device. The ESD bus is disposed across the first and second power domains without having a diode module interposed therebetween, thereby preventing the ESD current from flowing through the first and second devices.