Abstract: Provided is a water leakage detection device, including: a pair of metal electrodes containing a first end and a second end; a warning device connected to the first end of the pair of metal electrodes, and configured to issue a warning based on a potential difference between the pair of metal electrodes; and a power supply which is connected to the second end of the pair of metal electrodes, and configured to apply a voltage between the pair of metal electrodes.

Abstract: Provided is a water leakage detection device, including: a pair of metal electrodes containing a first end and a second end; a warning device connected to the first end of the pair of metal electrodes, and configured to issue a warning based on a potential difference between the pair of metal electrodes; and a power supply which is connected to the second end of the pair of metal electrodes, and configured to apply a voltage between the pair of metal electrodes.

Abstract: A parasitic ribbon sensor includes: a first conductive line including a first metal portion formed of a first metal; and a second conductive line including a second metal portion formed of a second metal being different from the first metal, the second conductive line being placed parallel to the first conductive line, being shaped in a ribbon shape together with the first conductive line.

Abstract: A power feeding system has a power receiving device having: a resonant circuit having a receiving coil, a resonant capacitor configured to resonate with the receiving coil, and a first switching element configured to change an electrical connection state of the resonant capacitor; and a resonance control unit configured to control the first switching element, and has a power feeding device having: a second switching element connected in series to a feeding coil; a drive signal generation unit configured to generate a drive signal for driving the feeding coil; a variation detection unit configured to detect the change in electrical connection state of the resonant capacitor; and a power feeding control unit configured to control electric power supplied to the feeding coil based on a period of the resonant state and a period of the non-resonant state that are estimated from the periodic waveform variation.

Abstract: A power feeding system includes a power feeding device and a power receiving device. The power receiving device includes: a resonant circuit including a receiving coil, a resonant capacitor configured to resonate with the receiving coil, and a resonance control transistor configured to control a resonant state by changing an electrical connection state of the resonant capacitor; a rectifying diode configured to rectify received power by the receiving coil; and a resonance control unit configured to set the resonance control transistor to a non-conductive state based on the received power and power consumption of the load during a period including a subsequent conducting period during which a current flows to the rectifying diode, and which is estimated in a resonant state of the resonant circuit.

Abstract: To prevent an overvoltage from being applied to a load in a power reception circuit of a power supply system. A power supply system is provided which includes a power supply device equipped with a power supply coil, and a power reception device equipped with a power reception coil. When a resonance circuit is in a resonance state, a peak voltage value of a voltage generated in the power reception coil is set higher than a prescribed voltage value. When the resonance circuit is in a non-resonance state, the peak voltage value of the voltage generated in the power reception coil is set lower than the prescribed voltage value.

Abstract: A power feeding system includes a power feeding device and a power receiving device. The power receiving device includes: a resonant circuit including a receiving coil, a resonant capacitor configured to resonate with the receiving coil, and a resonance control transistor configured to control a resonant state by changing an electrical connection state of the resonant capacitor; a rectifying diode configured to rectify received power by the receiving coil; and a resonance control unit configured to set the resonance control transistor to a non-conductive state based on the received power and power consumption of the load during a period including a subsequent conducting period during which a current flows to the rectifying diode, and which is estimated in a resonant state of the resonant circuit.

Abstract: A power feeding system has a power receiving device having: a resonant circuit having a receiving coil, a resonant capacitor configured to resonate with the receiving coil, and a first switching element configured to change an electrical connection state of the resonant capacitor; and a resonance control unit configured to control the first switching element, and has a power feeding device having: a second switching element connected in series to a feeding coil; a drive signal generation unit configured to generate a drive signal for driving the feeding coil; a variation detection unit configured to detect the change in electrical connection state of the resonant capacitor; and a power feeding control unit configured to control electric power supplied to the feeding coil based on a period of the resonant state and a period of the non-resonant state that are estimated from the periodic waveform variation.

Abstract: A power feeding system (100) includes a power feeding device (1) and a power receiving device (2). The power feeding device (1) includes: a drive transistor (13) connected to a feeding coil (11); a drive signal generation section (30) configured to generate a drive signal for driving the feeding coil (11); a crest value variation detection section (40) configured to detect the change in the resonant state of the resonant circuit (20) as a periodic waveform variation in a voltage excited in the feeding coil (11); and a drive control section (50) configured to determine whether or not electric power is suppliable to the power receiving device (2) based on the periodic waveform variation, and control to whether or not to continuously supply the drive signal to the drive transistor (13) based on a result of the determination.

Abstract: To prevent an overvoltage from being applied to a load in a power reception circuit of a power supply system. A power supply system is provided which includes a power supply device equipped with a power supply coil, and a power reception device equipped with a power reception coil. When a resonance circuit is in a resonance state, a peak voltage value of a voltage generated in the power reception coil is set higher than a prescribed voltage value. When the resonance circuit is in a non-resonance state, the peak voltage value of the voltage generated in the power reception coil is set lower than the prescribed voltage value.

Abstract: A power feeding system (100) includes a power feeding device (1) and a power receiving device (2). The power feeding device (1) includes: a drive transistor (13) connected to a feeding coil (11); a drive signal generation section (30) configured to generate a drive signal for driving the feeding coil (11); a crest value variation detection section (40) configured to detect the change in the resonant state of the resonant circuit (20) as a periodic waveform variation in a voltage excited in the feeding coil (11); and a drive control section (50) configured to determine whether or not electric power is suppliable to the power receiving device (2) based on the periodic waveform variation, and control to whether or not to continuously supply the drive signal to the drive transistor (13) based on a result of the determination.

Abstract: To perform wireless power transfer without needing a feedback coil, an electronic component includes: a drive transistor to be connected in series to a resonant circuit, the resonant circuit including a feeding coil for feeding power to a receiving coil and a resonant capacitor configured to resonate with the feeding coil; and a drive control section for controlling the drive transistor. The drive control section includes an ON-signal generation section for generating, when a potential difference across the drive transistor falls within a given threshold range, a control signal for controlling the drive transistor to a conductive state for a predetermined first period and thereafter controlling the drive transistor to a non-conductive state.

Abstract: An electronic component includes: a switching element to be connected to a resonant circuit, the resonant circuit including a power receiving coil to be supplied with power from a power feeding coil and a resonant capacitor configured to resonate with the power receiving coil, in which the switching element is to be connected in parallel to the power receiving coil together with the resonant capacitor and connected in series to the resonant capacitor; a transistor to be connected in series to a battery that is charged by DC power obtained by the power receiving coil; a charge control section for controlling a current flowing through the transistor so that a charge current flowing through the battery matches with a given current value by setting the switching element to a non-conductive state when an output voltage of the battery is equal to or less than a given threshold voltage.