Abstract: A system for communicating measurement data from each fuel cell or a group of fuel cells in a fuel cell stack, including a plurality of fuel cells and a plurality of stack plates, where one stack plate is between each fuel cell and on each end of the stack. The system includes a plurality of embedded smart plates where each embedded smart plate is mechanically and electrically coupled to at least one of the plurality of stack plates, and where each embedded smart plate includes optical transceivers on a top side and a bottom side of the smart plate. The system further includes at least one aggregator device having at least one optical transceiver to initiate a series of communications between the embedded smart plates to determine the location and data collected by each of the smart plates.

Abstract: A system for communicating measurement data from each fuel cell or a group of fuel cells in a fuel cell stack, including a plurality of fuel cells, a plurality of stack plates, and a plurality of embedded smart plates. The stack plates are between each fuel cell and on each end of the stack, and the plurality of embedded smart plates are mechanically and electrically coupled to at least one of the plurality of stack plates, and each smart plate including optical transceivers on the top side and the bottom side. The system further includes first and second aggregator devices, said first and second aggregator devices including at least one optical transceiver for communicating with the embedded smart plate adjacent to the first or second aggregator device, where one aggregator device initiates communication with the embedded smart plates and the other aggregator device completes communication.

Abstract: A system and method for monitoring fuel cells in a fuel cell group. The system includes a sensor circuit, such as a voltage sensor circuit, that monitors a condition of the fuel cells. If the sensor circuit detects a low performing cell, then it sends a signal to a tone generator that generates a frequency signal that switches a load into and out of the cell group. A voltage sensor detects the voltage of the cell group including the frequency signal, and sends the detected voltage signal to a tone decoder that decodes the frequency signal to determine that the fuel cells are low performing.

Abstract: A system that monitors fuel cells in a fuel cell group. The system includes a plurality of voltage sensors coupled to the fuel cells in the fuel cell group, where each sensor monitors a different voltage of the fuel cells and where lower priority voltage sensors monitor higher voltages and higher priority sensors monitor lower voltages. The system also includes a plurality of oscillators where a separate oscillator is coupled to each of the sensors. Each oscillator operates at a different frequency where higher frequency oscillators are coupled to lower priority sensors and lower frequency oscillators are coupled to higher priority sensors. A light source that receives frequency signals from the oscillators and switches on and off in response to the frequency signals. A light pipe receives the switched light signals from the light source and provides light signals at a certain frequency at an end of the light pipe.

Abstract: A measurement circuit that has particular application for detecting a high impedance measurement signal from a liquid water sensor. The measurement circuit includes a high impedance resistance-to-frequency conversion circuit that is coupled to the sensor and receives a resistance signal therefrom. The resistance-to-frequency conversion circuit includes an oscillator that converts the resistance signal to a representative frequency. The measurement circuit also includes a frequency-to-voltage conversion circuit that receives the frequency signal from the resistance-to-frequency conversion circuit, and converts the frequency signal to a representative voltage that provides an indication of water on the sensor.

Abstract: A system for communicating measurement data from each fuel cell or a group of fuel cells in a fuel cell stack, including a plurality of fuel cells, a plurality of stack plates, and a plurality of embedded smart plates. The stack plates are between each fuel cell and on each end of the stack, and the plurality of embedded smart plates are mechanically and electrically coupled to at least one of the plurality of stack plates, and each smart plate including optical transceivers on the top side and the bottom side. The system further includes first and second aggregator devices, said first and second aggregator devices including at least one optical transceiver for communicating with the embedded smart plate adjacent to the first or second aggregator device, where one aggregator device initiates communication with the embedded smart plates and the other aggregator device completes communication.

Abstract: A system for communicating measurement data from each fuel cell or a group of fuel cells in a fuel cell stack, including a plurality of fuel cells and a plurality of stack plates, where one stack plate is between each fuel cell and on each end of the stack. The system includes a plurality of embedded smart plates where each embedded smart plate is mechanically and electrically coupled to at least one of the plurality of stack plates, and where each embedded smart plate includes optical transceivers on a top side and a bottom side of the smart plate. The system further includes at least one aggregator device having at least one optical transceiver to initiate a series of communications between the embedded smart plates to determine the location and data collected by each of the smart plates.

Abstract: A measurement circuit that has particular application for detecting a high impedance measurement signal from a liquid water sensor. The measurement circuit includes a high impedance resistance-to-frequency conversion circuit that is coupled to the sensor and receives a resistance signal therefrom. The resistance-to-frequency conversion circuit includes an oscillator that converts the resistance signal to a representative frequency. The measurement circuit also includes a frequency-to-voltage conversion circuit that receives the frequency signal from the resistance-to-frequency conversion circuit, and converts the frequency signal to a representative voltage that provides an indication of water on the sensor.

Abstract: A high-precision Rogowski current transformer, the Rogowski coil is realized in a single printed circuit board while maintaining both the outside field rejection of a traditional Rogowski coil, and the increased output voltage similar to the multiple printed circuit board Rogowski coil arrangements.

Abstract: A method and apparatus for a high frequency resistance measurement instrument with a reasonable dynamic range, which militates against saturation in the presence of one or more large undesirable signals, the high frequency measurement instrument capable of employing multiple alternating currents of differing frequencies to maintain measurement capability despite signal chain saturation in the presence of a large undesirable signal.

Abstract: A method and apparatus for a high frequency resistance measurement instrument with a reasonable dynamic range, which militates against saturation in the presence of one or more large undesirable signals, the high frequency measurement instrument capable of employing multiple alternating currents of differing frequencies to maintain measurement capability despite signal chain saturation in the presence of a large undesirable signal.

Abstract: A high-precision Rogowski current transformer, the Rogowski coil is realized in a single printed circuit board while maintaining both the outside field rejection of a traditional Rogowski coil, and the increased output voltage similar to the multiple printed circuit board Rogowski coil arrangements.