Abstract: Techniques and apparatus for tuning a wireless data transmission system in an electronic device. One example method includes receiving a measured impedance value corresponding to a current user interaction state with respect to one or more antennas of a mobile device; determining a user interaction stability state of the mobile device based on the measured impedance value and a set of historical impedance values; classifying the current user interaction state based at least on the measured impedance value and a plurality of impedance values from the set of historical impedance values; and tuning the one or more antennas based on the classified current user interaction state and the determined user interaction stability state of the mobile device.

Abstract: A power supply system for an electric vehicle drivetrain includes series connected first and second high-voltage battery units, a circuit arrangement having high-power switching semiconductor devices connected to the battery units, and an electronic control system. During a charging mode, the control system controls the semiconductor devices to route high-voltage DC from a vehicle external charging source alternatingly to the battery units. During a power supply mode, the control system controls the operation of the semiconductor devices to supply high-voltage DC from both the battery units for driving a vehicle electrical traction machine of the electric vehicle drivetrain, wherein the supplied high-voltage DC has a voltage level corresponding to an accumulated voltage level of the series connected battery units.

Abstract: The problem of the present invention is to establish how to more accurately estimate the failure probabilities of the components of a machine system that has a small number of failure records.

Abstract: Provided are a battery diagnosis method and a battery diagnosis apparatus. The battery diagnosis apparatus receives time series data including at least one of a voltage, a current, and a temperature of a battery measured for a certain time period, receives non-time series data including battery impedance measured at a certain time point, and then predict the battery state information by inputting the time series data and the non-time series data to a battery prediction model.

Abstract: An electrochemical cell charging apparatus includes a charger to charge one or more electrochemical cells and a computing apparatus. The computing apparatus includes one or more processors and is operatively coupled to the charger. The computing apparatus is configured to charge an electrochemical cell using the charger, determine one or more indicators of the state of health of the electrochemical cell, and determine the state of health of the electrochemical cell based on the determined one or more indicators.

Abstract: A method and device for testing a battery that powers a body-wearable medical device. The battery is contacted via battery contacts and a capacitor is arranged in parallel with the battery contacts. During the battery test, a first capacitor voltage U1 is determined at a first time t1 and a second capacitor voltage U2 is determined at a second time t2 subsequent to time t1. A test current is drawn between time t1 and time t2. t1 is determined by the beginning of drawing the test current and time t2 is determined such that the capacitor voltage at time t2 is in a steady state and is substantially constant while the test current is being drawn. A charging state of the battery is determined from the difference in voltage between U1 and U2 and/or from a time difference between the time t1 and time t2.

Abstract: A battery degradation evaluation system includes a memory and a processor. The processor is configured to acquire state quantities of a battery mounted at a vehicle, derive probabilities, and evaluate degradation of the battery based on the derivation results. The probabilities are a short-term degradation probability of the battery degrading in a pre-specified short period, a medium-term degradation probability of the battery degrading in a period that is longer than the short period, and a long-term degradation probability of the battery degrading in a period that is longer than the medium period. When a number of the state quantities is smaller, the processor sets a higher weighting for a combined degradation probability for the short period and medium period, which is calculated from the long-term degradation probability. When the number of state quantities is larger, the processor sets a higher weighting for the short-term degradation probability.

Abstract: Predictive rechargeable battery management is provided, which includes obtaining performance data on a battery cell of multiple rechargeable battery cells within a product, and comparing the performance data of the battery cell to statistical data on battery cell performance of a plurality of battery cells. Further, the managing includes determining, based on the comparing, that performance of the battery cell is trending away from the statistical data of battery cell performance of the plurality of battery cells. Further, the managing includes performing a battery-related action based on the performance of the battery cell trending away from that of the plurality of battery cells.

Abstract: A battery degradation evaluation system includes a memory and a processor. The processor is configured to acquire state quantities of a battery mounted at a vehicle, derive probabilities, and evaluate degradation of the battery based on the derivation results. The probabilities are a short-term degradation probability of the battery degrading in a pre-specified short period, a medium-term degradation probability of the battery degrading in a period that is longer than the short period, and a long-term degradation probability of the battery degrading in a period that is longer than the medium period. When a number of the state quantities is smaller, the processor sets a higher weighting for a combined degradation probability for the short period and medium period, which is calculated from the long-term degradation probability. When the number of state quantities is larger, the processor sets a higher weighting for the short-term degradation probability.

Abstract: This disclosure relates to thermal event detection for battery packs of electrified vehicles. An example electrified vehicle includes a battery assembly including an enclosure assembly surrounding at least one battery array, and a controller configured to receive information associated with the battery assembly and detect a thermal event based on the information. The controller is configured to issue a plurality of corrective action commands following detection of the thermal event.

Abstract: A method for checking defects in a lithium ion secondary battery includes primarily charging and degassing the lithium ion secondary battery after manufacture of the secondary battery, secondarily charging and discharging the secondary battery and then measuring one or more of OCVs and IRs of lithium ion secondary battery cells; pressurizing and aging the secondary battery by aging the secondary battery in a state in which a pressure of a designated magnitude or more is applied to the secondary battery, and checking whether or not the secondary battery cells are defective by re-measuring the one or more of OCVs and IRs of the secondary battery cells and then comparing the re-measured one or more of the OCVs and the IRs to the previously measured one or more of the OCVs and the IRs.

Abstract: This disclosure relates to thermal event mitigation for battery packs of electrified vehicles. An example electrified vehicle includes a battery assembly with an enclosure assembly surrounding at least one battery array and a bag configured to selectively release nitrogen. The electrified vehicle further includes a controller configured to issue a plurality of corrective action commands in response to a detected thermal event. One of the corrective action commands includes instructing the bag to generate and release nitrogen within the enclosure assembly. Among other benefits, which will be appreciated from the below description, the disclosed arrangement promptly mitigates a thermal event of the battery assembly and takes additional corrective actions, such as providing various prompts and status indicators to the user.

Abstract: A method for monitoring a state variable of at least one battery cell of a battery. The battery has at least two battery cells that are arranged adjacent to one another. A first electrically conductive surface is provided at a boundary surface of a first battery cell and a second electrically conductive surface is provided at a boundary surface of a second battery cell. The electrically conductive surfaces are arranged electrically insulated from each other. An electrical voltage is applied between the two electrically conductive surfaces. An electrical variable produced due to an effect of the electrical voltage is analyzed. The state variable on the basis of the analysis is determined.

Abstract: Embodiments disclosed herein relate to a battery pack that may be used in an battery energy storage system. In an embodiment, the battery pack may include an integrated battery management system (BMS) having isolated, distributed, daisy-chained battery module controllers. The daisy-chained battery module controllers may be coupled to a battery pack controller, which may charge and/or discharge the battery pack using the battery modules controllers and a balancing charger.

Abstract: An electronic shelf label system is provided. There is provided a method in which an electronic shelf label periodically transmits its remaining battery capacity to a server in a electronic shelf label system according to the present invention, and the server converts the battery level into a remaining battery life (time) and provides the same, so that a manager can check the remaining battery life in a management mode of the server and a terminal, and easily manage an electronic shelf label using a battery.

Abstract: A sleep disrupting apparatus disposed in a vehicle includes a processor and at least one vibration generator. The vibration generator is connected to the processor and is located in the vehicle in a position proximate to a passenger such that vibrations generated by the vibration generator are transmitted to the passenger. The processor determines a time index, generates at least three vibration signals consistent with the time index, and transmits the three vibration signals to the at least one vibration generator. The three vibration signals are separated from one another by two time intervals. The two time intervals are not equal to one another.

Abstract: An electronic warning device with scent dispersion mechanism is disclosed, which comprises: an electronic element; and at least two scent sources, featured with different vaporization temperatures while being disposed simultaneously on the electronic element. In an embodiment, there are two scent sources, i.e. a first scent source that can be vaporized at a first vaporization temperature, and a second scent source that can be vaporized at a second vaporization temperature, whereas the second vaporization temperature is higher than the first vaporization temperature.

Abstract: An early warning and monitoring system is disclosed for battery cells and battery packs. During normal cycling of a battery, surface temperature, voltage, current and impedance may be monitored to determine if abnormalities exist in the battery and/or battery structure. The abnormalities may be advantageously detected using battery temperature characteristics, where the characteristics are subject to rule-based processing to determine impending battery failure. By receiving advance notice of failure, a warning signal may be transmitted to provide notice and/or allow corrective action to be taken.

Abstract: The present invention relates to a device and method for displaying the lifecycle of a surge protection device, and more particularly to a device and method for displaying the lifecycle of a surge protection device, which detects an increase in leakage current according to a deterioration in performance of the surge protection device in order to provide notice of a replacement time for the surge protection device. According to the present invention, it is possible to for a user to provide notice of a replacement time by displaying the lifecycle of a surge protection device (SPD) to the outside. Additionally, as another effect of the present invention, it is possible to confirm an amount of leakage current flowing into the ground of the SPD and whether the SPD is properly installed on a ground line by using a current and ground state detecting sensor.

Abstract: Provided is an apparatus for controlling charging of a portable terminal equipped with a solar battery that converts solar energy into an electrical energy, the apparatus including a thermistor in which a resistance value changes according to a temperature change; a comparator which outputs a first signal when a temperature surrounding the thermistor is less than a preset reference temperature as determined by the resistance value change of the thermistor according to the temperature change and outputs a second signal when the temperature is at least the preset reference temperature or more; and a charging unit which is activated and receives the electrical energy from the solar battery to charge a battery when the first signal is inputted from the comparator, and is deactivated and blocks the charge of battery in case the second signal is inputted.

Abstract: A system and method are provided for monitoring and reporting leakage currents caused by a load that is coupled to an AC supply line. A sensor positioned adjacent to an AC supply line senses an amperage difference between currents traveling along the AC supply line. A processor coupled to the sensor compares the amperage difference to a threshold value. A reporting device coupled to the processor generates a report at least when the amperage difference exceeds the threshold value.

Abstract: A method and instrument capable of producing an audible tick that increases with detected gas concentrations, is suitable for indicating relatively low levels of gas concentrations, and enables the adjustment of the tick rate to provide an accurate audible indication of gas levels at higher concentrations. The method and instrument entail sensing the presence of the gas and generating an analog sensor output based on a concentration of the gas in the environment, and then processing the analog sensor output through an audio circuitry to generate therefrom an audible tick having a frequency in proportion to the analog sensor output. The processing step includes the use of an analog control loop signal to selectively increase and decrease the frequency of the audible tick.

Abstract: For detecting swelling in batteries supplying power to electrical equipment, at least one contact sensor such as quantum tunneling composite (“QTC”) based pressure-capacitive sensor coated on one surface with a layer of conductive material such as indium tin oxide (“ITO”) or a capacitive sensor coated with the same conductive material is used for attachment to each battery. A capacitance measuring module including a microcontroller is connected to the contact sensor and measures the capacitance of the ITO—coated conductor. If the capacitance under measurement represents an increase in capacitance exceeding a predetermined threshold, indicative of battery swelling, a call for battery replacement and interruption of battery power to the electrical equipment are initiated.

Abstract: One embodiment of the invention is a combination of a tank and an optical switch, where the tank has a wall forming an enclosure for holding fluids, and the optical switch has a housing floatable in a liquid stored in the tank, and further has a first light fiber having proximal and distal ends, where the first light fiber is connected to a light source at the distal end, and a second light fiber having proximal and distal ends, the second light fiber connected to a light detector at the distal end, the first and second fibers separated by a gap, and a rigid rod connected to the housing and to the tank enclosure, where the rod moves in response to movement of the housing.

Abstract: For detecting swelling in batteries supplying power to electrical equipment, at least one contact sensor such as quantum tunneling composite (“QTC”) based pressure-capacitive sensor coated on one surface with a layer of conductive material such as indium tin oxide (“ITO”) or a capacitive sensor coated with the same conductive material is used for attachment to each battery. A capacitance measuring module including a microcontroller is connected to the contact sensor and measures the capacitance of the ITO-coated conductor. If the capacitance under measurement represents an increase in capacitance exceeding a predetermined threshold, indicative of battery swelling, a call for battery replacement and interruption of battery power to the electrical equipment are initiated.

Abstract: An in-vehicle communication system is disclosed. The in-vehicle communication system is configured to connect a short range wireless communication link between an in-vehicle apparatus and a portable device, and predicts a battery level threshold reach time, which is a time when a battery level of a battery of the portable device reaches below a threshold. When it is determined that the battery level threshold reach time is prior to a vehicle travel end time, the in-vehicle communication system notifies the passenger of prompt battery charge information to prompt the passenger to charge the battery of the portable device.

Abstract: A fuel battery system is comprised of a power source circuit, a rotating electrical machine that is a load, a memory device and a control unit. Here, a battery learning system corresponds to an arrangement including a fuel battery that is a structural component of the power source circuit, a high frequency signal source, an electric current detection means, a voltage detection means, the memory device and a battery learning part that is a structural element of the control unit. An impedance value can be obtained from alternating current components of respective detecting values of the electric current detection means and the voltage detection means. The battery learning unit has an I-V characteristic curve learning module that learns an I-V characteristic curve and a learning prohibition judgment module that judges whether or not an acquiring interval of the impedance value is over a predetermined threshold interval set in advance, and prohibits learning if the former is over the latter.

Abstract: Provided is an apparatus for controlling charging of a portable terminal equipped with a solar battery that converts solar energy into an electrical energy, the apparatus including a thermistor in which a resistance value changes according to a temperature change; a comparator which outputs a first signal when a temperature surrounding the thermistor is less than a preset reference temperature as determined by the resistance value change of the thermistor according to the temperature change and outputs a second signal when the temperature is at least the preset reference temperature or more; and a charging unit which is activated and receives the electrical energy from the solar battery to charge a battery when the first signal is inputted from the comparator, and is deactivated and blocks the charge of battery in case the second signal is inputted.

Abstract: Systems, apparatuses and methods for detecting internal cell faults using online and real-time sensing techniques, and providing an accurate and reliable early warning for the incoming failure of battery cells hours or days prior to failure. A system is configured to perform real-time and direct measurement of battery cell parameters of temperature, voltage, and AC impedance through online sensing. These parameters may be simultaneously processed using advanced probabilistic and/or fuzzy logic-based algorithms to provide an early warning for the incoming failure of battery cells in a battery pack. This technology may safeguard the LIB battery packs while allowing them to operate at or near 100% capacity in both transportation and stationary applications.

Abstract: A capacitive passenger detector includes: a capacitive sensor having main, sub and guard electrodes; a sensor characteristic measurement unit for applying an alternating voltage signal to each electrode and for converting a current in each electrode to a voltage; and a controller. The controller defines a current in the guard electrode as a reference current when voltages of the main and guard electrodes have a same potential. The controller defines a current flowing direction of the guard electrode to be negative when the voltage of the main electrode is higher than the guard electrode. The controller defines the current flowing direction of the guard electrode to be positive when the voltage of the main electrode is lower than the guard electrode. The controller corrects the voltage of the main electrode based on the current of the guard electrode so that a corrected voltage is set to be a passenger determination data.

Abstract: The invention relates to a system which can give a vehicle user an indication related to a direction to take to find back his vehicle. The said system comprises a hand-held object (1) to be taken by the user and a module (2) to be installed on the vehicle. The module (2) is equipped with a first emitting device (3) of a first radio signal (5). The latter (5) is a directed radio signal which is emitted within an angular sector of an angle A less than 90°.

Abstract: A method of providing assistance for locating a radio-frequency identification (RFID) device is provided. The RFID device preferably comprises a power source having a power level and a feedback device. The method comprises determining the power level of the power source is below a first predetermined power level, and transmitting a first signal that indicates the power level of the power source is below the first predetermined power level. Thereafter, the method comprises receiving a second signal that instructs the RFID device to activate the feedback device, and operating the feedback device in response to receiving the second signal.

Abstract: A method for controlling a cleaning device is presented, which includes the following steps. A cleaning device includes a control unit, a fan module, an optical emitter, and an optical sensor. The optical emitter and the optical sensor are located in an air inlet of the fan module. The control unit is preset with a first impedance value (Z1), a second impedance value (Z2), and a threshold, where 0<Z1<Z2. Then, the control unit reads an impedance value (Z) of the fan module. If Z1<Z<Z2, the control unit drives the fan module. If Z2<Z, the control unit reads a detected value of the optical sensor. If the detected value exceeds the threshold, the control unit drives the fan module, so as to increase a suction force of the fan module. If the detected value is smaller than the threshold, the control unit turns off the fan module.

Abstract: An animal confinement system including at least one transmitter, a loop antenna associated with each transmitter, a loop monitor associated with each loop antenna, a remote communication device and a communication device. The transmitter sends a signal to the loop antenna. The loop monitor senses at least one attribute of the signal. The communication device is communicatively connected with the loop monitor. The communication device communicates at least one attribute to the remote communication device.

Abstract: A voltage sensing device with which high-precision voltage sensing is possible without the need to obtain a unique correction constant for each device. A pair of voltage input nodes NCk and NCk-1 is selected from voltage input nodes NC0-NCn in switch part 10, and they are connected to sensing input nodes NA and NB in two types of patterns with different polarity (forward connection, reverse connection). Sensing input nodes NA and NB are held at reference potential Vm by voltage sensing part 20, and current Ina and Inb corresponding to the voltage at voltage input nodes NCk and NCk-1 flows to input resistors RIk and RIk-1. Currents Ina and Inb are synthesized at different ratios in voltage sensing part 20, and sensed voltage signal S20 is generated according to the synthesized current Ic. Sensed voltage data S40 with low error is generated according to the difference between the two sensed voltage signals S20 generated in the two connection patterns.

Abstract: An electronic apparatus that enables a remaining battery capacity to be checked without requiring the battery to be loaded into the electronic apparatus. In this electronic apparatus, a battery lid closes a battery chamber that accommodates a battery. An opening/closing detection device detects opening/closing of the battery lid. An acquisition device acquires battery information of the battery when the opening/closing detection device detects that the battery lid opens. A storing device stores the battery information acquired by the acquisition device. A display device displays the battery information that is stored in the storing device, and displays the battery information of a battery that is not accommodated in the battery chamber.

Abstract: An electronic apparatus that enables a remaining battery capacity to be checked without requiring the battery to be loaded into the electronic apparatus. In this electronic apparatus, a battery lid closes a battery chamber that accommodates a battery. An opening/closing detection device detects opening/closing of the battery lid. An acquisition device acquires battery information of the battery when the opening/closing detection device detects that the battery lid opens. A storing device stores the battery information acquired by the acquisition device. A display device displays the battery information that is stored in the storing device, and displays the battery information of a battery that is not accommodated in the battery chamber.

Abstract: A method and apparatus is provided for determining when a battery, or one or more batteries within a battery pack, undergoes an undesired thermal event such as thermal runaway. The system uses a conductive member mounted in close proximity to, or in contact with, an external surface of the battery or batteries to be monitored. A resistance measuring system such as a continuity-tester or an ohmmeter is coupled to the conductive member, the resistance measuring system outputting a first signal when the temperature corresponding to the battery or batteries is within a prescribed temperature range and a second signal when the temperature exceeds a predetermined temperature that falls outside of the prescribed temperature range.

Abstract: The invention provides a system and battery including a state-of-charge indicator (SOCI) to monitor and display the amount of charge within the battery. The SOCI is capable of operating in a hibernate mode, an active mode, and/or a sleep mode. The battery may be manufactured, shipped and/or stored with the SOCI operating in a power-saving hibernate mode. The SOCI may exit the hibernate mode and begin operating in active mode if a physical key connected to the battery is removed. In addition, the SOCI may operate in a sleep mode while the battery is not being used to conserve power. Furthermore, the invention provides a method of making a battery including a SOCI to monitor and display the state of charge of the battery.

Abstract: A wireless communication device (200) and method (300) adapted to prolong the useful life of an energy storage device is disclosed. In its simplest form, it can include: determining (310) a limit temperature discharge energy rate of an energy storage device; sensing (320) a temperature range threshold in proximity to the energy storage device; and adjusting (330) a discharge energy rate in response to the determined limit temperature discharge energy rate (310) and sensed temperature range threshold (320). The device (200) and method (300) can automatically and dynamically manage current drain of an energy storage device when a certain temperature range threshold is reached, to maintain the energy storage device within desired specifications and tolerances. This can prolong the useful life of the energy storage device and help to maintain a maximum recharging capacity.

Abstract: A flame detecting method and device are provided to improve the accuracy of flame detection and reduce the possibilities of the false fire alarm. The flame detecting method and device capture a plurality of images of a monitored area; determines whether a moving area image exists in the plurality of images; analyzes at least one of a color model and a flickering frequency of the moving area image to generate a first analyzed result and compares the first analyzed result with a feature of a reference flame image; analyzes at least one of a variation of a location and an area of the moving area image to generate a second analyzed result and compares the second analyzed result with a predetermined threshold; and determines whether the moving area image is a flame image based on results of the comparing steps.

Abstract: A method and apparatus is provided for determining when a battery, or one or more batteries within a battery pack, undergoes an undesired thermal event such as thermal runaway. The system uses a conductive member mounted in close proximity to, or in contact with, an external surface of the battery or batteries to be monitored. A resistance measuring system such as a continuity-tester or an ohmmeter is coupled to the conductive member, the resistance measuring system outputting a first signal when the temperature corresponding to the battery or batteries is within a prescribed temperature range and a second signal when the temperature exceeds a predetermined temperature that falls outside of the prescribed temperature range.

Abstract: A method of supporting portable digital devices includes providing each device with an installed service application. The service application for each device monitors operational parameters associated with other applications that are running on the device. When a monitored parameter suggests a device operational problem, the service application generates an alert, and it provides the device's user with information about how to resolve the alert. The application also may transmit the alert, along with data showing the applications running and the monitored parameters at the time of the alert, to a remote service operation. Also, during non-alert conditions, the application may periodically transmit data showing the applications running and the monitored parameters at the time of the transmission. The service operation may use this data to identify trends, manage device operation, or perform other functions.

Abstract: A system for and method of estimating the state-of-age of a secondary cell utilizing an adaptive group filter algorithm, includes battery current, voltage, and temperature sensors, a communication device, and a controller communicatively coupled to the sensors and device, configured to filter data by analyzing only sample data points from instantaneous charge or discharge events, selecting only a sample of n instantaneous points for further regression, including n/2 charge event points and n/2 discharge event points, and separately averaging the charge and discharge event points, and further configured to determine the state-of-age by determining a resistance slope based on the rate of current and voltage change between the averages of the points, and matching the slope to a calibrated scalar or relational database.

Abstract: A device suitable for wireless communication with a network entity. The device comprises a functional unit configured to monitor an operational state of the device and, in response to detecting that the device is in a de-powered operational state, to inform the network entity of an ability of the device to wirelessly communicate with the network entity during a future time interval while the device remains in a de-powered operational state. A second functional unit capable of wireless communication with the network entity may also be provided and may be selectably powered from either a main power source or an alternate power source such that the second functional unit is powered from the alternate power source during the future time interval and becomes unpowered from the alternate power source after the future time interval. Thus, de-powered devices can be located and communicated with more easily.

Abstract: A battery powered device that includes a battery pack having a fuel gauge to display a state of charge of the battery pack. The fuel gauge is located on the battery pack such that when the battery pack is engaged with the battery powered device the fuel gauge is visible through a window provided on the housing of the device.

Abstract: A method for calibrating a smoke detector includes adjusting the sensitivity of the smoke detector to get a consistent predetermined response over the expected operating range. The sensitivity is generally consistent for all detectors and an independent offset value is determined for each detector. This offset value basically corresponds to the signal from the detector in a clean atmosphere. The sensitivity of the smoke detector is determined by measuring the response at different levels of obscuration and then appropriately adjusting the output of the light source of the detector. This process is repeated until the desired sensitivity is achieved. Thereafter, the offset value is measured or calibrated and stored in the smoke detector for use in setting alarm values.

Abstract: An apparatus and method for monitoring at least one battery condition. A ac signal is applied to a battery. A difference between a signal output from the battery and a threshold determines a battery condition. The determined battery condition is transmitted remotely from the battery location through a controller to a network server and/or is visibly displayed at the battery location.

Abstract: An apparatus supporting both identification of a battery type and communications over an interface between a battery and an electronic device is disclosed. The electronic device includes a processor for communicating with communications circuitry of the battery. Identification circuitry associated with the processor enables a determination of the type of battery with which the electronic device is connected. If a “smart” battery capable of carrying out serial communications with the electronic device is connected, the electronic device further provides means for carrying out communications between the processor and the communication circuitry of the battery.

Abstract: An object of the invention is to render replacement of controllers for identifying failure information unnecessary. Failure monitor units 24 and 26 in power supplies 10 and 12 are connected mutually via paths 38 and 40, the failure monitor units 24 and 26 in the power supplies 10 and 12 are connected to failure monitor units 30 and 32 in controllers 14 and 16 via paths 34 and 36, and LEDs 1 and 2 are connected to paths 34 and 36. The failure monitor unit 24 transfers, when a failure occurs in the power supply 10, failure information to the failure monitor unit 26 in the power supply 12 via the path 38. The LED 1 is lit by both the failure monitor units 24 and 26. The failure monitor units 24 and 26 transfer failure information indicating failure occurrence in the power supply 10 to the failure monitor units 30 and 32 in controllers 14 and 16 via a path 34. The failure monitor units 30 and 32 notify a maintenance PC of the failure occurrence in the power supply 10.