Abstract: Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by a power cable that includes a first power lead conducting an inlet current having an inlet current direction, and a second power lead conducting an outlet current having an outlet current direction opposite to the inlet current direction. The power cable passes through a center region of a toroid core one or more times, and a secondary winding on the toroid core is configured to induce a secondary voltage indicative of a difference between the inlet current and the outlet current, which defines the leakage current. The system includes a prognostic processor that is configured to calculate a heater health indication based on the secondary voltage, which is indicative of the heater health.

Abstract: Apparatus and associated methods relate to health-monitoring of a magnetic speed probe. An inductive coil of the magnetic speed probe is used for two purposes: i) to sense a changing magnetic field caused by rotation of a rotating member; and ii) to radiatively transmit radio-frequency signals for determining the health of the magnetic speed probe. A signal generator coupled to the inductive coil of the magnetic speed probe generates the radio-frequency signals that, when conducted by the inductive coil, causes an inductive coil to act as a radio transmitter by radiatively transmitting the radio-frequency signals. The radio-frequency signals transmitted by the inductive coil are detected by a radio receiver. The radio-frequency signals received are indicative of health of the magnetic speed probe.

Abstract: Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

Abstract: Apparatus and associated methods relate to detecting leakage current in a powered electrical system. Leakage current is detected by comparing a high-frequency response signal with a high-frequency reference signal. A high-frequency excitation signal is coupled, via an inducer, into the powered electrical system at a first location. The high-frequency response signal is sensed, via a signal sensor, at a second location of the powered electrical system. Because the electrical dynamics of the powered electrical system can change in response to system degradation that results in leakage current, changes in the high-frequency response signal can be indicative of leakage. Thus, the high-frequency response signal is compared, by a controller, with a high-frequency reference signal. The high-frequency reference signal can be a high-frequency response signal obtained at a reference time, at which the powered electrical system is operating without leakage.

Abstract: Apparatus and associated methods relate to health-monitoring of a magnetic speed probe. An inductive coil of the magnetic speed probe is used for two purposes: i) to sense a changing magnetic field caused by rotation of a rotating member; and ii) to radiatively transmit radio-frequency signals for determining the health of the magnetic speed probe. A signal generator coupled to the inductive coil of the magnetic speed probe generates the radio-frequency signals that, when conducted by the inductive coil, causes an inductive coil to act as a radio transmitter by radiatively transmitting the radio-frequency signals. The radio-frequency signals transmitted by the inductive coil are detected by a radio receiver. The radio-frequency signals received are indicative of health of the magnetic speed probe.

Abstract: A system for monitoring the quality of voltage supplied by a power supply includes a voltage variation detection module and a controller. The voltage variation detection module has one or more level detection circuits that each receive a signal indicating the supplied voltage, thereby producing an amplitude signal representing a temporal variation in the voltage during a capture interval. The controller determines the capture interval, provides a capture control signal that causes the level detection circuit(s) to receive the voltage during the capture interval, receives the respective amplitude signal(s) from each of the level detection circuit(s), and produces one or more output signals, each representing the amplitude signal(s) and the associated capture interval, thereby providing an indication of the voltage quality. A method of using the system is also disclosed.

Abstract: A system for monitoring the quality of voltage supplied by a power supply includes a voltage variation detection module and a controller. The voltage variation detection module has one or more level detection circuits that each receive a signal indicating the supplied voltage, thereby producing an amplitude signal representing a temporal variation in the voltage during a capture interval. The controller determines the capture interval, provides a capture control signal that causes the level detection circuit(s) to receive the voltage during the capture interval, receives the respective amplitude signal(s) from each of the level detection circuit(s), and produces one or more output signals, each representing the amplitude signal(s) and the associated capture interval, thereby providing an indication of the voltage quality. A method of using the system is also disclosed.

Abstract: A water intrusion mitigation device for use in enclosures housing electric components and equipment that are sensitive to humidity includes a thermoelectric cooler and a water electrolyzer. The thermoelectric cooler has two sides: a first side that is configured to be heated with the application of an electric current and a second side that is configured to cooled with the application of an electric current. The water electrolyzer is a proton exchange membrane that is in thermal communication with the second side of the thermoelectric cooler.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by a power cable that includes a first power lead conducting an inlet current having an inlet current direction, and a second power lead conducting an outlet current having an outlet current direction opposite to the inlet current direction. The power cable passes through a center region of a toroid core one or more times, and a secondary winding on the toroid core is configured to induce a secondary voltage indicative of a difference between the inlet current and the outlet current, which defines the leakage current. The system includes a prognostic processor that is configured to calculate a heater health indication based on the secondary voltage, which is indicative of the heater health.

Abstract: In an embodiment, the invention is directed to a device including an environmental condition sensor, a light sensor; and a control module. The control module associates a light intensity above a defined threshold with an open-door status of a container. In another embodiment, a device includes an environmental condition sensor, a rewriteable memory that stores environmental condition data from the environmental condition sensor, and a wireless communication module that transmits stored environmental condition data. Embodiments of the invention may be useful to provide techniques for monitoring environmental conditions within a container, such as a refrigerated trailer.

Abstract: In an embodiment, the invention is directed to a device comprising an environmental condition sensor, a light sensor; and a control module, wherein the control module associates a light intensity above a defined threshold with an open-door status of a container. In another embodiment, a device comprises an environmental condition sensor, a rewriteable memory that stores environmental condition data from the environmental condition sensor, and a wireless communication module that transmits stored environmental condition data. Embodiments of the invention may be useful to provide techniques for monitoring environmental conditions within a container, such as a refrigerated trailer.

Abstract: A data communication system allocates use of a common data communication medium shared by a plurality of stations. During each transmission cycle, the communication medium carries data packets of varying priority which each station receives. The stations are allocated use of the communication medium during one or more priority intervals as a function of the priority of the packet which the station is ready to transmit. Each station is synchronized to a transmission cycle period which is divided into subperiods. Certain types of packets are relegated to transmission and reception within predetermined subperiods.

Abstract: A redundant common communication system for a distributed process control or data processing system has multiple stations which are coupled to at least two redundant communication channels (such as communication busses). Each station includes a transmitter for transmitting data packets and a receiver for receiving data packets. Each data packet includes a channel selection field which identifies a selected channel to be used by all station during a succeeding transmission of a data packet. Each station makes an assessment of quality of each channel based upon the occurrence of errors when that channel is in use. The station computes a margin value based upon assessed quality factors. When the station gets an opportunity to transmit, the channel selection field of the transmitted packet identifies a channel which is selected based upon the margin value and the frequency of previous use of each of the channels.

Abstract: A data communication system allocates use of a common data communication medium shared by a plurality of stations. During each transmission cycle, the communication medium carries data packets of varying priority which each station receives. The stations are allocated use of the communication medium during one or more priority intervals as a function of the priority of the packet which the station is ready to transmit. Each station is synchronized to a transmission cycle period which is divided into subperiods. Certain types of packets are relegated to transmission and reception within predetermined subperiods.

Abstract: A data communication system allocates use of a common data communication medium shared by a plurality of stations. During each transmission cycle, the communication medium carries data packets of varying priority which each station receives. The stations are allocated use of the communication medium during one or more priority intervals as a function of the priority of the packet which the station is ready to transmit. Each station is synchronized to a transmission cycle period which is divided into subperiods. Certain types of packets are relegated to transmission and reception within predetermined subperiods.

Abstract: In order to accurately detect and commmunicate the position of a data location in a raster type luminescent display utilizing light-sensitive detection means, the permitted response time for the light detection means is extended by allowing detection of only a portion of the data locations during each scan of raster display means. Maintenance of a predetermined relationship between the number of raster scans in a detection cycle and the particular data locations for which detection is possible on each scan permits exact definition of a target data location. Detection is aided by the superimpositon of a luminescent cursor associated with each data location for which detection is permitted as the raster display is scanned.