Abstract: Devices and methods for improved voltage source transfer switching. First and second voltage sources (primary and alternate) are connectable to a load via corresponding first and second switches, which may comprise SCRs. A controller operates the switches according to various transfer methods. In some transfer methods, the timing of the switching operation is critical. For example, switching times may be optimized to reduce or prevent transformer saturation due to the dc flux built up during the transfer event. The controller force commutates off the primary source switch by turning on the appropriate alternate source switch for a brief period of time. In this case, the alternate source switches are “pulsed” (rather than being turned on continuously), so that the switches will naturally commutate off at the next current zero cross. Subsequently, the volt-second balancing control logic will permanently turn on these switches at the appropriate time.

Abstract: In the case of a data carrier (1) or an integrated circuit (5) for the data carrier (1), an ESD protection circuit (8) is formed by means of a series connection (9) comprising a first protection diode (10) and a protection stage (11) together with a second protection diode connected in parallel with the series connection (9), and a rectifier circuit (13) connected with the ESD protection circuit (8) is provided, which comprises a rectifier diode connected in parallel with the ESD protection circuit (8), wherein the rectifier diode takes the form of a Schottky diode (21) with a parasitic p/n junction (26) and wherein the Schottky diode (21) with the parasitic p/n junction (26) forms the second protection diode of the ESD protection circuit (8).

Abstract: A high voltage magnetic compression modulator including a low-voltage part including an energy source connected to a primary winding of a pulsed transformer, and a high-voltage part including a secondary winding of the pulsed transformer connected to a capacitor, the capacitor being connected to a magnetic switch, the magnetic switch being connected to a load, characterized in that a unidirectional low-impedance path for the charge of the capacitor is connected in parallel to the load, and wherein said low impedance path includes a freewheeling diode.

Abstract: The present invention provides a power line terminating circuit and method and a power line relay device for setting indoor power lines to a state adapted to communications by making impedances match each other irrespective of a device connected, thereby enabling noise entering from an electric device to the power lines to be reduced. By a capacitor (33) provided between connection ends (35A) and (35B) and an inductor (34) provided between a termination (32A) of an indoor power line (1A) and the connection end (35A), a series resonance circuit having a series resonance point in a frequency band which is higher than a frequency of a power source voltage and is lower than a communication frequency band is configured. A resistor (31) having a resistance value corresponding to a characteristic impedance of the indoor power line (1A) and an indoor power line (1B) is provided in parallel with the inductor (34).

Abstract: Method and device for protecting against electrostatic discharge. The method includes configuring a gate of at least one upper transistor of a transistor network connected between power rails to be biased to a prescribed value, and coupling an electrostatic discharge event to a gate of a lower transistor of the transistor network. The at least one upper and at least one lower transistors of the transistor network are respectively coupled between the power rails from a higher voltage to a lower voltage.

Abstract: A circuit and method for controlling a MOSFET based switch that includes two back-to-back FET to block current flow in the OFF state irrespective of the polarity of the voltage differential across the switch. The MOSFET based switch further has a built-in current limit function by sensing the current flow through one of the two MOSFET switches. Furthermore, the bilateral current-limited switch further includes circuitry required for controlling both P type and N type FET in either common drain or common source configuration.

Abstract: An electrostatic discharge protective circuit including an ESD protective circuit which has a trigger terminal and forms a discharge path from a first node to a second node when trigger signals are supplied to the trigger terminal, a trigger circuit included in a circuit to be protected which is connected between the first and second nodes, the trigger circuit having a first MOS device, and which functions as a part of the circuit to be protected at the time of normal operation when ESD voltage is not applied, and forms a conductive path between a drain and source of the MOS device when ESD voltage of a predetermined value or more is applied to the first node during a normal operation, and supplying the trigger signals to the trigger terminal of the ESD protective circuit when the first MOS device becomes conductive.

Abstract: In a power generation system which includes a plurality of sets of direct current power sources and power converters which are connected to the direct current power sources to convert a direct current power into an alternating current power, the power converters being connected in parallel to supply the alternating current power to a system power supply, from the plurality of power converters in the system, one power converter is set as a master machine which detects an islanding operation state in which power supply from the system power supply is stopped, and setting is executed so as to cause the remaining power converters not to detect the islanding operation state. When the master machine is not present among the power converters in operation, the master machine is selected from the power converters in operation in accordance with a predetermined condition.

Abstract: A method for controlling an uninterruptible power supply (UPS) for servicing a load is disclosed. The UPS has a bypass feed path operable in parallel with an inverter feed path, the bypass feed path being engagable with the load via a first switch, and the inverter feed path and being engagable with the load via a second switch. The method includes: generating a paralleling detection signal indicative of the bypass feed path operating to service the load in parallel with the inverter feed path; and, in response to the presence of the paralleling detection signal, modifying a control signal to an inverter such as to drive toward equalization the bypass current and the inverter current. As a result, and in response to the two paths operating to service the load in parallel, the method tends to cancel circulation current generated between the bypass feed path and the inverter feed path.

Abstract: A protection apparatus (48) is provided which in addition to protecting electronic equipment (5) from overvoltage transients is also able to provide an indication of whether or not said transients are due to impedances associated with poor earthing. In one embodiment the protection apparatus (48) includes an input terminal (42), an output terminal (60) and a ground reference terminal (62) with a transient blocking unit (50) arranged to isolate the output terminal (60) in response to the destructive transient voltages. A gas discharge tube (46) is provided to conduct transient currents associated with the destructive transient voltages to the earth reference connection point (62); and an indicator (58), such as a fuse or circuit breaker is placed in series with the transient blocking unit (50) to indicate the presence of a voltage resulting from an interaction of the transient currents with an earthing impedance.

Abstract: Methods and apparatus for providing uninterruptible power are provided by aspects of the invention. One aspect is more particularly directed to an uninterruptible power supply for providing power to a load. The uninterruptible power supply includes an input to receive input power, an output to provide output power, a back-up power source coupled to the output to provide backup power at the output, a contactor coupled to the input and having an open state and a closed state, a contactor control circuit having an output coupled to the contactor to provide an output voltage to control an operational state of the contactor, the contactor control circuit being configured to provide an output voltage having a first voltage level to the contactor to control the contactor to switch from the open state to the closed state and to provide a second output voltage having a second voltage level to maintain the contactor in the closed state.

Abstract: A load driving device for controlling a driving and a stop of a load through on/off switching of a semiconductor device under the control of a driving circuit, includes an overcurrent detecting unit that compares, with a prescribed judgment voltage, an inter-electrode voltage which is generated when a current flows between a first electrode and a second electrode of the semiconductor device, and judges that an overcurrent is flowing through the semiconductor device when the inter-electrode voltage is higher than the judgment voltage, and a diagnosing unit that performs a diagnosis as to whether the overcurrent detecting unit is operating normally in a state that the semiconductor device is a on-state. When the diagnosing unit judges that the overcurrent detecting unit is not operating normally, the diagnosing unit outputs an instruction signal for turning off the semiconductor device, to the driving circuit.

Abstract: In one aspect, a polyphase power converter includes an input adapted to couple to a polyphase AC source, a positive DC output, and a negative DC output. The polyphase power converter also includes a first plurality of circuits and a second plurality of circuits. In one embodiment, each of the first plurality of circuits is adapted to receive a plurality of phases of the polyphase AC source and to produce a DC voltage at the positive DC output. Each of the second plurality of circuits is adapted to receive a plurality of phases of the AC source and to produce a DC voltage at the negative DC output. In one embodiment, the polyphase power converter includes a plurality of switching devices and each of the plurality of switching devices is adapted to isolate at least one phase of the polyphase AC source from at least one of the plurality of circuits.

Abstract: A power supply in which a feed voltage (Us) is guided through at least one longitudinal branch to at least one output, the at least one branch having a disconnect fuse formed as a controlled semiconductor switch (SW1) and a monitoring unit (UWE) being set up to supply a disconnect signal (s1) to the semiconductor switch when there are changes in voltage or current beyond pre-definable tolerances, in which at least one auxiliary semiconductor switch (H1A), likewise triggered by the monitoring unit (UWE), is connected in parallel to the semiconductor switch (SW1) and in the event of an overload absorbs a substantial portion of the overload current in the branch.

Abstract: A metal oxide varistor integrally formed with a heat protection structure that will automatically go to open circuit in conditions of overheating due to sustained over-voltages. The metal oxide varistor integrally formed with a heat protection structure has a body, an insulation bracket, a number of terminals and a fuse. The insulation bracket is deposited on the body and has a number of slots. The fuse connects to the body and one of the terminals. The fuse is mounted one of the slots of the insulation bracket. The fuse reacts to the overheating timely and the melting fuse spreads quickly with the assistance of capillary action evolved by the slots of the insulation bracket to speed up the action to go to open circuit in against damage due to sustained over-voltages.

Abstract: An uninterruptible power supply wherein an isolation device is automatically tested during normal operation to ensure that it is capable of effectively isolating the input from an auxiliary power supply during emergency operation. The uninterruptible power supply includes an input for coupling to a main power supply, an output for connection to an electrical load, an auxiliary power supply and a selective isolation device configured to isolate the auxiliary power supply from the input during emergency operation. First components establish a reverse polarity across the isolation device for a test period during normal operation, and second components monitor a voltage proportional to the input voltage to the isolation device and output an error signal if the monitored voltage remains or rises above a first reference value during the test period.

Abstract: A method for protecting an electrical generator which includes providing an electrical generator which is normally synchronously operated with an electrical power grid; providing a synchronizing signal from the electrical generator; establishing a reference signal; and electrically isolating the electrical generator from the electrical power grid if the synchronizing signal is not in phase with the reference signal.

Abstract: An RC-triggered electrostatic discharge (ESD) power clamp circuit and method for providing ESD protection uses a control circuit with a latch to selectively activate a clamping transistor to discharge ESD on a first voltage rail to a second voltage rail.

Abstract: An adapter device includes a DC/DC adapter to receive DC power from a DC power source, and output a regulated DC voltage (Vout). A source determination circuitry receives the DC power from the DC power source and compares a magnitude of a voltage of the DC power with a reference magnitude of a reference voltage (Vref). When the magnitude of the voltage of the DC power is greater than the reference magnitude, a data signal (Vdata) having a first value is output. When the magnitude of the voltage of the DC power is less than the reference magnitude, the Vdata signal having a second value is output. The Vdata signal is received by control circuitry of an electronic device. When the Vdata signal has the first value, the electronic device operates in a first mode where battery charging circuitry is disabled. When the Vdata signal has the second value, the battery charging circuitry is enabled.

Abstract: A system and method for controlling an electronic circuit breaker prevents the circuit breaker from contributing its own delay to a power interruption time window on a load. A monitor coupled to a control processor in the circuit breaker causes the control processor to operate in a low-energy consumption sleep mode if it detects a power interruption. During the sleep mode, the control processor draws current from an energy storage device until the power source is reconnected to the control processor. Because the control processor operation is suspended rather than stopped during the power interruption, the control processor does not need to conduct any preliminary power up operations when power is resumed.