Abstract: According to one embodiment, a power convertor includes a buck-boost circuit to be applied with an input voltage to convert the input voltage into an output voltage for output, the input voltage being generated by a power generation module that generates direct-current power; a switching controller that executes maximum power-point tracking to control power conversion of the buck-boost circuit such that the power generation module generates maximum direct-current power; and a mode controller that causes the switching controller to execute the maximum power-point tracking when an input current from the power generation module is larger than a preset current threshold, and when the input current is equal to or less than the current threshold, causes the switching controller to stop the maximum power-point tracking, and cause the buck-boost circuit to output the input voltage as the output voltage without the power conversion.

Abstract: According to one embodiment, a power convertor includes a buck-boost circuit; a switch driver, a switching controller, and a positive input terminal and a negative input terminal. In maximum power-point tracking, the switching controller causes the buck-boost circuit to stop outputting the output voltage, and varies the voltage value of the input voltage in a given range, which is from a lower-limit voltage value at which the switch driver is operable, by switching between the positive input terminal and the negative input terminal while varying a duty factor.

Abstract: A wireless connection device for establishing a connection path between a parent device and a child device through one more relay devices includes one or more processors that determines whether the signal strength between the child device and each of the relay devices is greater than or equal to a first threshold value; when the signal strength is determined to be greater than or equal to the first threshold value, selects, from among a plurality of possible communication paths for which the signal strength has been determined to be greater than or equal to the first threshold value, a communication path that minimizes a hop count; and, when the signal strength is less than the first threshold value for all of the plurality of possible communication paths, selects, from among the plurality of possible communication paths, a communication path that has the largest signal strength.

Abstract: According to one embodiment, a power convertor includes a buck-boost circuit; a switch driver, a switching controller, and a positive input terminal and a negative input terminal. In maximum power-point tracking, the switching controller causes the buck-boost circuit to stop outputting the output voltage, and varies the voltage value of the input voltage in a given range, which is from a lower-limit voltage value at which the switch driver is operable, by switching between the positive input terminal and the negative input terminal while varying a duty factor.

Abstract: According to one embodiment, a power convertor includes a buck-boost circuit to be applied with an input voltage to convert the input voltage into an output voltage for output, the input voltage being generated by a power generation module that generates direct-current power; a switching controller that executes maximum power-point tracking to control power conversion of the buck-boost circuit such that the power generation module generates maximum direct-current power; and a mode controller that causes the switching controller to execute the maximum power-point tracking when an input current from the power generation module is larger than a preset current threshold, and when the input current is equal to or less than the current threshold, causes the switching controller to stop the maximum power-point tracking, and cause the buck-boost circuit to output the input voltage as the output voltage without the power conversion.

Abstract: The present invention provides, in one aspect, a sensor unit that includes: a sensor configured to measure a physical quantity that characterizes a state of a solar cell module; a wireless unit wirelessly outputting measurement results of the sensor; a case housing the sensor and the wireless unit; and a spacer configured to attach the case to a frame for the solar cell module such that the wireless unit is separated from the frame by a prescribed distance.

Abstract: A converter for use in a distributed power system for stepping up or down a voltage of a power source connected thereto includes a step up/down circuit that receives the voltage, steps up or steps down the voltage from the power source, and then outputs the stepped up/down voltage; and a control circuit that detects the voltage from the power source and transmits a control signal for stepping up or stepping down the voltage to the step up/down circuit. The control circuit transmits an identification signal that identifies the converter and is configured to receive an identification signal from another converter when the other converter is connected to the converter.

Abstract: A wireless connection device for establishing a connection path between a parent device and a child device through one more relay devices includes one or more processors that determines whether the signal strength between the child device and each of the relay devices is greater than or equal to a first threshold value; when the signal strength is determined to be greater than or equal to the first threshold value, selects, from among a plurality of possible communication paths for which the signal strength has been determined to be greater than or equal to the first threshold value, a communication path that minimizes a hop count; and, when the signal strength is less than the first threshold value for all of the plurality of possible communication paths, selects, from among the plurality of possible communication paths, a communication path that has the largest signal strength.

Abstract: The present invention provides, in one aspect, a sensor unit that includes: a sensor configured to measure a physical quantity that characterizes a state of a solar cell module; a wireless unit wirelessly outputting measurement results of the sensor; a case housing the sensor and the wireless unit; and a spacer configured to attach the case to a frame for the solar cell module such that the wireless unit is separated from the frame by a prescribed distance.

Abstract: A converter for use in a distributed power system for stepping up or down a voltage of a power source connected thereto includes a step up/down circuit that receives the voltage, steps up or steps down the voltage from the power source, and then outputs the stepped up/down voltage; and a control circuit that detects the voltage from the power source and transmits a control signal for stepping up or stepping down the voltage to the step up/down circuit. The control circuit transmits an identification signal that identifies the converter and is configured to receive an identification signal from another converter when the other converter is connected to the converter.

Abstract: A transformer for use in a power supply has a primary winding, a secondary winding, a bobbin on which the primary and secondary windings are separately wound, and a core subassembly mounted in the bobbin. An opening is formed in the cylindrical portion of the bobbin, and an inside core in the magnetic core insertion hole and an outside core located outside the hole are adhesively bonded together via a spacer through the opening in the cylindrical portion.

Abstract: A transformer for use in a power supply has a primary winding, a secondary winding, a bobbin on which the primary and secondary windings are separately wound, and a core subassembly mounted in the bobbin. An opening is formed in the cylindrical portion of the bobbin, and an inside core in the magnetic core insertion hole and an outside core located outside the hole are adhesively bonded together via a spacer through the opening in the cylindrical portion.