Abstract: System and methods for measuring operating parameters of a fuel cell system are presented. In certain embodiments, the systems and methods may be configured to measure a high frequency resistance of a fuel cell system. A method for measuring a high frequency resistance of a fuel cell system may include inducing a current signal and a voltage signal through the FC system at a center frequency using a switched load. The current signal and the voltage signal may then be measured and filtered to isolate the current signal and the voltage signal from noise signals occurring in the FC system. A high frequency resistance of the FC may then be calculated based on the filtered current and voltage signals.

Abstract: A method for providing calibration synchronization pulses in a pulse width modulation (PWM) signal including fuel cell voltage measurement pulses. The method includes providing a sequence of voltage signals representative of the voltage of the fuel cells in a fuel cell group, where the sequence of voltage signals are provided in the order of the position of the fuel cells in the group. The method also includes providing a sequence of calibration pulses and combining the sequence of voltage signals and the sequence of calibration pulses so that the calibration pulses are provided before a voltage signal of a first cell in the group. The method modulates the combined sequence of the voltage signals and the calibration pulses using an inverted saw tooth wave to provide the PWM signal, where a width of the pulses representing the voltage signals are proportional to a width of the pulses representing the calibration pulses.

Abstract: A method for providing calibration and synchronization pulses in a pulse width modulation (PWM) signal including cell voltage measurement pulses, where the calibration pulses are four calibration pulses having a pattern of a narrow width high voltage pulse followed by a wide width low voltage pulse followed by a narrow width high voltage pulse followed by a wide width low voltage pulse that has a very low probability of occurring in a practical fuel cell system. The method modulates a combined sequence of the voltage measurement signals and the calibration pulses using an inverted saw tooth wave to provide the PWM signal, where a width of the pulses representing the voltage signals are proportional to a width of the pulses representing the calibration pulses.

Abstract: A health monitoring system for a fuel cell stack using current fuel cell architecture to enable the electronic control unit (ECU) to continue to monitor the health of the fuel cell stack despite a component failure. The system uses an embedded measurement module (EMM) connected to a group of fuel cells in the fuel cell stack to monitor the health of that group of fuel cells. The EMM produces a pulse width modulation signal that is sent to the ECU. A total voltage value for the group of fuel cells is embedded into the calibration signal or end of frame sequence. The ECU uses an algorithm to determine a missing voltage of at least one fuel cell in the event of the component failure of that fuel cell by adding up the cumulative value for each fuel cell reporting their voltage and subtracting that value from the total voltage value found in the end of frame sequence.

Abstract: System and methods for measuring operating parameters of a fuel cell system are presented. In certain embodiments, the systems and methods may be configured to measure a high frequency resistance of a fuel cell system. A method for measuring a high frequency resistance of a fuel cell system may include inducing a current signal and a voltage signal through the FC system at a center frequency using a switched load. The current signal and the voltage signal may then be measured and filtered to isolate the current signal and the voltage signal from noise signals occurring in the FC system. A high frequency resistance of the FC may then be calculated based on the filtered current and voltage signals.

Abstract: A health monitoring system for a fuel cell stack using current fuel cell architecture to enable the electronic control unit (ECU) to continue to monitor the health of the fuel cell stack despite a component failure. The system uses an embedded measurement module (EMM) connected to a group of fuel cells in the fuel cell stack to monitor the health of that group of fuel cells. The EMM produces a pulse width modulation signal that is sent to the ECU. A total voltage value for the group of fuel cells is embedded into the calibration signal or end of frame sequence. The ECU uses an algorithm to determine a missing voltage of at least one fuel cell in the event of the component failure of that fuel cell by adding up the cumulative value for each fuel cell reporting their voltage and subtracting that value from the total voltage value found in the end of frame sequence.

Abstract: A flow control device for use in a wellbore which has a nozzle with an output to provide a jet of fluid and a structure proximate the nozzle. The structure is positioned a set distance away from the output of the nozzle, where the set distance is greater than a length of a potential core of the jet of fluid.

Abstract: A method for providing calibration synchronization pulses in a pulse width modulation (PWM) signal including fuel cell voltage measurement pulses. The method includes providing a sequence of voltage signals representative of the voltage of the fuel cells in a fuel cell group, where the sequence of voltage signals are provided in the order of the position of the fuel cells in the group. The method also includes providing a sequence of calibration pulses and combining the sequence of voltage signals and the sequence of calibration pulses so that the calibration pulses are provided before a voltage signal of a first cell in the group. The method modulates the combined sequence of the voltage signals and the calibration pulses using an inverted saw tooth wave to provide the PWM signal, where a width of the pulses representing the voltage signals are proportional to a width of the pulses representing the calibration pulses.

Abstract: A method for providing calibration and synchronization pulses in a pulse width modulation (PWM) signal including cell voltage measurement pulses, where the calibration pulses are four calibration pulses having a pattern of a narrow width high voltage pulse followed by a wide width low voltage pulse followed by a narrow width high voltage pulse followed by a wide width low voltage pulse that has a very low probability of occurring in a practical fuel cell system. The method modulates a combined sequence of the voltage measurement signals and the calibration pulses using an inverted saw tooth wave to provide the PWM signal, where a width of the pulses representing the voltage signals are proportional to a width of the pulses representing the calibration pulses.

Abstract: An embodiment of a method of shifting a valve between a plurality of flow condition positions, includes the steps of providing a mechanical indexer device in operational connection with a valve, the indexer device including a primary path defining a sequence through a plurality of valve positions at and between open and closed and a detent moveable along the primary path; providing at least one alternate path from a point along the primary path to a preceding position on the primary path along the sequence; shifting the valve to a subsequent position in the sequence; and shifting the valve to the preceding position in the sequence.

Abstract: A flow control device for use in a wellbore which has a nozzle with an output to provide a jet of fluid and a structure proximate the nozzle. The structure is positioned a set distance away from the output of the nozzle, where the set distance is greater than a length of a potential core of the jet of fluid.

Abstract: A tool for breaking a shaft includes two aligned tubular elements (20, 22), each having an end portion for receiving a contiguous length of the same shaft (2). Means are provided for locking each end portion against rotation relative to the shaft length received therein, and the elements are adapted for rotation relative to one another with the end portions so locked, to relatively twist the shaft lengths and shear the lengths at the interface between them. The element end portions will normally have juxtaposed faces, and it is preferred that the faces are moved towards each other during the relative rotation and as the shaft lengths are twisted relative to each other. This assists in achieving a substantially planar face at the fracture plane. A compressible washer may be disposed between the juxtaposed faces. This can stabilize the moving parts as the shaft is broken, although normally screw threads on the tubular elements will effect the movement of the element.

Abstract: A tool for breaking a shaft includes two aligned tubular elements (20, 22), each having an end portion for receiving a contiguous length of the same shaft (2). Means are provided for locking each end portion against rotation relative to the shaft length received therein, and the elements are adapted for rotation relative to one another with the end portions so locked, to relatively twist the shaft lengths and shear the lengths at the interface between them. The element end portions will normally have juxtaposed faces, and it is preferred that the faces are moved towards each other during the relative rotation and as the shaft lengths are twisted relative to each other. This assists in achieving a substantially planar face at the fracture plane. A compressible washer may be disposed between the juxtaposed faces. This can stabilize the moving parts as the shaft is broken, although normally screw threads on the tubular elements will effect the movement of the element.

Abstract: An image forming apparatus is particularly usable with a relatively stiff receiving sheet. In one embodiment, it includes a transfer member around which the receiving sheet is attached. To maintain good contact between the receiving sheet and the transfer member, a pair of rollers are positioned to engage the receiving sheet in non-imaged margins to hold it intimately to the transfer member. The sheet may also be engaged at other positions in its path in the non-imaged margins to control its movement. In another embodiment, corona applied to the sheet before separation from the transfer member is specially biased to discourage premature or excessive separation because of the stiffness of the sheet. The bias can be then changed to encourage separation if a more flexible receiving sheet is used.

Abstract: A method of forming duplex color images on a receiving sheet passes the receiving sheet through a fuser twice for the first image and once for the second image. The process includes the step of determining which of the toner images should have a higher gloss and forming that toner image first so that it receives the greatest fusing energy. Preferably, the determining step is accomplished by determining which image receives more photographic content.

Abstract: A toner image carried by a receiving sheet is fused by heat and pressure applied by first and second fusing members. To compensate for heat lost from the pressure member to the receiving sheet, the fuser has at least two speeds, a first fast speed, which is utilized for the first revolution of the fusing member contacting the toner image and a second slower speed to which the fuser is changed at the end of such first revolution.

Abstract: A non-oxide ceramic (16) for electronic packages and a method of producing electronic packages using a non-oxide ceramic is provided. In accordance with the present invention, the non-oxide ceramic (16) is coated with silicon dioxide (15) and a bonding glass (14) having diboron trioxide is used to attach other package components such as semiconductor chips (18), leadframes (13), and heatsinks (11) to the non-oxide ceramic (16).

Abstract: Image frame length control apparatus and methods are disclosed which have particular utility in a printing or reproduction apparatus that writes one or more images on a transported photosensitive media such as a photoconducting drum or continuous-loop web. When an electronic writing system or optical exposure system is used to expose a driven media on a line-by-line basis, a variation in media thickness causes the latent image frame to be written with an inaccurate frame length. Consequently, a degraded print is produced.The latent image frame length is corrected during exposure, by adding or omitting one or more lines in the image frame. Alternatively, the exposure of an image is offet by an interval corresponding to one-half of the total length discrepancy between the uncorrected image frame length and the image frame length that would be written if the media surface speed was at a median level.

Abstract: A reproduction apparatus has an endless web with perforations or other indicia triggering image formation and receiving sheet presentation. To correct for error in perforation location the distance between perforations is measured and a delay after sensing one or both perforations is adjusted accordingly. Preferably, the distance between perforations is measured by an encoder temporarily connected to the apparatus when a new web is installed by a serviceperson.

Abstract: An improved semiconductor die bonding structure and method for electrical devices is described which utilizes a ductile foil between the semiconductor die and the base of the device package. The die is sealed to the foil with a die bonding material formed from a titania free base glass to which has been added 23.6 to 36.4 weight percent lead titanate powder to give a glass plus ceramic mixture consisting essentially of (by weight percent) 2.5-10.7% GeO.sub.2, 0-2.3% SiO.sub.2, 58.6-78.5% PbO, 0-5.3% PbF.sub.2, 7-13% B.sub.2 O.sub.3, 2.5-6.9% Al.sub.2 O.sub.3, 0-5.3% ZnO, 0.4-2.3% V.sub.2 O.sub.5, 0-5.3% CdO, and 6.2-9.6% TiO.sub.2. The ductile foil is bonded to the ceramic package base directly without intermediate layers or alternatively by means of an improved foil bonding glass material consisting essentially of (by weight percent) 10-15% SiO.sub.2, 45-55% PbO, 8-12% ZnO, 2-5% Al.sub.2 O.sub.3, and 25-30% B.sub.2 O.sub.3.