Abstract: Control methods and apparatus are disclosed for operating a full-bridge inverter at resonant frequency mode, hybrid frequency mode, and fixed frequency mode. The operating frequency of the inverter equals to the user programmed frequency if the user programmed frequency is above the resonant tank frequency; and the operating frequency is synchronized with the resonant tank frequency if the user programmed frequency is below the resonant tank frequency.

Abstract: A circuit comprises a detector circuit and a protection triggering circuit in a discharge lamp system. The detector circuit detects both open lamp and shorted lamp conditions and is coupled with detecting devices, such as sensing capacitors. A DC bias is added to the sensing capacitors so that capacitor voltages are always greater than zero volts. The output voltage of the detector circuit is coupled to the protection triggering circuit, which triggers an open lamp protection when open lamp condition occurs and a shorted lamp protection when shorted lamp condition occurs.

Abstract: An array of fuel cell systems are electrically couplable in series and/or parallel combinations to provide a variety of output powers, output current and/or output voltages. The fuel cell systems are “hot swappable” and redundant fuel cell systems may automatically replace faulty fuel cell systems to maintain output power, current and/or voltage, with or without switching. The configuration of fuel cell systems may be automatic and may be based on desired power, current and/or voltage, and/or based on the operating parameters of the fuel cell systems and/or power supply system.

Abstract: A method for responding to an open lamp condition in a discharge lamp system is disclosed. The method monitors a current feedback signal flowing through a lamp and a voltage feedback signal indicative of a voltage across said lamp. A switch is used to switch between the current feedback signal to the voltage feedback signal upon detection of an open lamp condition.

Abstract: Control methods and apparatus are disclosed for operating an inverter at resonant mode, where the inverter adapts its frequency to the resonant tank characteristics before a lamp is struck, and operates at fixed frequency after the lamp is struck. Disclosed embodiments combine the advantages of operation in fixed mode as well as the variable mode.

Abstract: Methods and apparatus are disclosed for protecting circuits from damages caused by elevated temperatures. Presented embodiments illustrate IC thermal protection circuits that shut down power delivery circuits when the circuit temperature reaches a predefined upper threshold and restart the circuit when the circuit cools down to a predefined lower threshold. Other embodiments provide soft shutdown and soft restart, where not only the temperature range between the shutdown and the restart is predetermined, but also the time between the start of a shutdown process and the complete shutdown is controllable.

Abstract: The present invention introduces methods and circuits to amplify audio signals for driving speakers. An additional feedback circuit is added in an audio amplifier to couple the amplifier stage and output stage of the audio amplifier. The feedback circuit turned off as long as output voltages of the audio amplifier are not near saturation. The feedback circuit is turned on to reduce audible noises if output voltages of the audio amplifier are near saturation.

Abstract: A thermodynamic system that produces mechanical, electrical power, and/or fluid streams for heating or cooling. The cycle contains a combustion system that produces an energetic fluid by combustion of a fuel with an oxidant. A thermal diluent may be used in the cycle to improve performance, including but not limited to power, efficiency, economics, emissions, dynamic and off-peak load performance, and/or turbine inlet temperature (TIT) regulation and cooling heated components. The cycle preferably includes a heat recovery system and a condenser or other means to recover and recycle heat and the thermal diluent from the energetic fluid to improve the cycle thermodynamic efficiency and reduce energy conversion costs. The cycle may also include controls for temperatures, pressures, and flow rates throughout the cycle, and controls power output, efficiency, and energetic fluid composition.

Abstract: A shell for an electrical appliance includes a base, a cover, and a plug-receiving assembly. The plug-receiving assembly includes a recess attached to the cover for receiving a plug of the electrical appliance. The recess has a bottom and two opposing sides. The bottom supports the plug, and the opposing sides have protrusions for retaining the plug in the recess. The plug-receiving assembly further includes a slanted guide formed on the bottom of the recess for guiding the plug in the recess. A user may remove the plug from the recess by the pulling an electrical wire attached to the plug to move the plug along the slanted guide and out from the recess. Additionally, the plug-receiving assembly may include a mounting grove adjacent to the slanted guide for retaining the electrical wire.

Abstract: An auxiliary device for a connector has a body, a wire unit and plug. The wire unit is mounted securely in the body and extends out of the body from a first end of the body. The plug is formed on a second end of the body and is perpendicular to the wire unit. Therefore, the position of the wire unit is fixed when the plug is inserted into a socket.

Abstract: The present invention provides a method and apparatus for dynamically correcting overshoot and undershoot errors in an analog integrated circuit by improving the reaction time (?t) of the analog integrated circuit. Equivalently, an error correction circuit is disclosed including an overshoot correction circuit and an undershoot correction that are only activated to reduce overshoot and undershoot errors by increasing the bandwidth of the integrated circuit when either undershoot or overshoot errors are detected.

Abstract: A voltage regulating circuit has a first switch, a transformer and a second switch. The first switch has an input node, a first node and a second node. The transformer is connected to the switches has a first coil and a second coil. The first coil and the second coil respectively have an end, and the second coil is connected to the first coil in series at a node. The node between the first and second coils is connected to the second node of the first switch. The second switch is connected to the transformer and has a first node, a second node and an output node. The first node is connected to the end of the first coil. The second node is connected to the first node of the first switch. The transformer will not heat up when the transformer needs not to be used.

Abstract: An inverter comprising a low-side switching element in series with a first primary winding; a high-side switching element in series with a second primary winding, where the combination of the low-side switching element and first primary winding is connected in parallel with the combination of the high-side switching element and the second primary winding; and a clamping capacitor having one terminal connected to the first primary winding and having a second terminal connected to the second primary winding. Other embodiments are described and claimed.

Abstract: A method for controlling a switching power converter which includes a central capacitor exchanges charge between the capacitor and plural nodes of a first terminal, and then transfers the charge between the capacitor and plural nodes of a second terminal. The charge interchanged between the capacitor and the nodes establishes the amount of power transferred during each cycle. The charge which is interchanged is controlled by selecting the electrical phase between the currents drawn from the nodes and the voltages at the nodes.

Abstract: A fault detection circuit and a short-circuit detection circuit for a Cold Cathode Fluorescent Lamp (CCFL) driver integrated circuit having a power bridge and a CCFL load are disclosed that includes a reference circuit operable to generate a reference current in response to an external component, a replica component having a dimension substantially less than the components of the power bridge, a multiplexer circuit, and a comparator circuit. The replica component and the multiplexer circuit pass the reference current and the replica current to the comparator circuit respectively.

Abstract: An automatic flow measuring device is used in an industry where accuracy in dispensing of liquid is necessary. It is fully automatic in nature and is used with a PLC (programmable logic controller) to give the system intelligence and reporting capability. The automatic flow measuring device for measuring fluid flow includes an automatically operated valve, a tee connector operatively coupled to the automatically operated valve, an elongated member defining a measuring chamber coupled to the tee connector, at least a first fluid level sensor mounted on the elongated member at a first position thereon and a second fluid level sensor mounted on the elongated member at a second position thereon. The first and second sensors are preferably electronic and send signals to the PLC which opens and closes the automatically operated valve.

Abstract: A detector circuit monitors the phase relationship between the lamp voltage and the excitation voltage, and if one or more conditions are met, triggers the open lamp protection process in a discharge lamp system. The detection circuit can be incorporated into a lamp voltage feedback circuit and implemented on the integrated circuit level with less cost and circuit complexity.

Abstract: Electrochemical fuel cell stacks comprising a plurality of membrane electrode assemblies stacked in an alternating manner, such that the polarity of adjacent membrane electrode assemblies are opposite, are disclosed. The fuel cell stacks comprise a plurality of membrane electrode assemblies, each membrane electrode assembly comprising an anode fluid distribution layer, a cathode fluid distribution layer, a polymer electrolyte membrane interposed between the anode and cathode fluid distribution layers, an anode electrocatalyst layer interposed between the polymer electrolyte membrane and the anode fluid distribution layer, and a cathode electrocatalyst interposed between the polymer electrolyte membrane and the cathode fluid distribution layer, wherein the plurality of membrane electrode assemblies are stacked in an alternating manner such that the polarity of adjacent membrane electrode assemblies are opposite, and wherein the plurality of membrane electrode assemblies are externally jumpered.

Abstract: A self-healing power grid control system includes a power grid having a plurality of network islands with a plurality of linear and non-linear loads. A plurality of control sensors communicate with the power grid to monitor the electrical characteristics of the power grid. A plurality of controlled relays are in electrical communication with the plurality of non-linear loads. A battery energy storage system (ESS) is in electrical communication with a main power source and a network island. A first restoration controller is in electrical communication with the control sensors, the controlled relays, and with the battery ESS. The first restoration controller receives control signals from the control sensors, and in response to detecting an irregularity in the power grid, automatically actuates the battery ESS to stabilize power to the linear loads, and disconnects selected controlled relays to disconnect power to a calculated percentage of the non-linear loads.

Abstract: A battery charging circuit monitors the IC temperature through monitoring the charging die temperature, or directly monitoring the IC temperature using a temperature sensor. A maximum temperature allowed for the charging die is predetermined. The charging circuit is capable of reducing charging current at the predetermined maximum temperature value. The charging die signal is compared by a reference signal to achieve the reduction of charging current at the maximum allowed temperature value.