Abstract: Current pulsing improves the performance of fuel cells in a fuel cell stack based power system. Voltage clamping limits the voltage peaks that occur after a current pulse. In a hybrid power system, an electric storage device supplies the loads during current pulsing. The electric storage device may sink current to achieve the voltage clamping, and/or power system may employ other the voltage clamping circuits.

Abstract: A fuel cell system determines each of a battery charging current error, a battery voltage error, and a stack current error. The fuel cell system regulates current through a series pass element in response to a greater of the determined errors. Thus, the fuel cell system operates in three modes: battery voltage limiting mode, stack current limiting mode and battery charging current limiting mode. Additionally, there can be a fourth “saturation” mode where the stack voltage VS drops below the battery voltage VB as the load pulls even more current. Individual fuel cell systems can be combined in series and/or parallel to produce a combined fuel cell system having a desired output voltage and current.

Abstract: An electric power plant includes an array of fuel cell systems. The 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.

Abstract: A hybrid power module suitable for use in an array of hybrid power modules comprises a fuel cell stack, an energy storage device, charger circuit operable to charge the energy storage device from the fuel cell stack and/or an external power source at approximately a defined voltage; a stack disconnect switch operable to provide and remove an electrical path between the fuel cell stack and a terminal of the power module, and a unidirectional current flow device electrically coupled to provide a unidirectional current path from the charger circuit to the terminal of the power module when forward biased.

Abstract: A hybrid power module suitable for use in an array of hybrid power modules comprises a fuel cell stack, an energy storage device, charger circuit operable to charge the energy storage device from the fuel cell stack and/or an external power source at approximately a defined voltage; a stack disconnect switch operable to provide and remove an electrical path between the fuel cell stack and a terminal of the power module, and a unidirectional current flow device electrically coupled to provide a unidirectional current path from the charger circuit to the terminal of the power module when forward biased.

Abstract: The present invention is generally directed to systems and methods for distributing a non-odorized gas. In one embodiment, an inner pipe containing a non-odorized gas at a first pressure is routed through an outer pipe adapted to contain an odorized fluid at a second pressure less than the first pressure. As a result of the pressure differential, a leak in the inner pipe will not permit the odorized fluid in the outer pipe to flow into the inner pipe. When the non-odorized gas is hydrogen, this prevents a stream of hydrogen gas that is possibly contaminated with odorants from reaching a fuel cell. Furthermore, a leak in the outer pipe or a leak in both the inner and outer pipes will result in the release of the odorized fluid into the environment, allowing leaks to be detected before dangerous or harmful levels are reached.

Abstract: Antibodies to maternal status factors are produced and isolated. They are used in a diagnostic assay to determine maternal status in cattle. The maternal status is evaluated using a test device which contains immobilized antibody to the bovine factor. In addition, a liquid sampling device which allows only a predetermined amount of biological liquid sample to contact the test device is provided.

Abstract: A system and method for synchronizing interactive content with particular scenes in a television program for use with an interactive television system. An HTML page displays both the television program and interactive functionality which allows the presentation to the user of specific information, such as facts and observations, which is synchronized to and interrelated with particular content within the television program. The system and method enables the user to enter responses to program-related questions and can be utilized for implementing a rewards-based user-interactive viewing experience. The system and method also enables an advertiser to synchronize advertisements to particular scenes within a television program, thus allowing the advertiser to tie products to the program the user is viewing.