Abstract: A contactless rechargeable alkaline secondary battery includes an alkaline secondary battery; a power receiver circuit having receiver coils and a resonance capacitor and adapted to receive AC power via magnetic field resonance, the resonance capacitor connected with the receiver coils L1 to L4; a rectifier circuit adapted to rectify the AC power; a current limiter circuit adapted to limit a charging current flowing from the rectifier circuit to the alkaline secondary battery; and an outer casing configured to be cylindrical in shape, adapted to house the alkaline secondary battery, and provided with a positive terminal and a negative terminal, the positive terminal being connected with a positive pole of the alkaline secondary battery and the negative terminal being connected with a negative pole of the alkaline secondary battery, wherein the power receiver coils are shaped like a sheet of an electric wire wound along a plane.

Abstract: The polarity detection circuit includes a first diode with anode receiving a first phase of the AC power supply voltage and a second diode with anode receiving a second phase, opposite the first phase. The detection circuit further includes a constant-voltage power supply outputting a positive constant voltage. A first reference-voltage output circuit outputs a voltage corresponding to the constant voltage when the AC voltage of the first phase is positive, and outputs a voltage at a cathode of the second diode when the AC voltage of the first phase is negative. The detection circuit also includes a first signal output circuit that compares a first voltage, corresponding to a voltage at the cathode of the first diode, and a voltage output from the first reference-voltage output circuit and that outputs a signal indicative of polarity of the AC voltage having the first phase according to a comparison result.

Abstract: A contactless rechargeable alkaline secondary battery includes an alkaline secondary battery; a power receiver circuit having receiver coils and a resonance capacitor and adapted to receive AC power via magnetic field resonance, the resonance capacitor connected with the receiver coils L1 to L4; a rectifier circuit adapted to rectify the AC power; a current limiter circuit adapted to limit a charging current flowing from the rectifier circuit to the alkaline secondary battery; and an outer casing configured to be cylindrical in shape, adapted to house the alkaline secondary battery, and provided with a positive terminal and a negative terminal, the positive terminal being connected with a positive pole of the alkaline secondary battery and the negative terminal being connected with a negative pole of the alkaline secondary battery, wherein the power receiver coils are shaped like a sheet of an electric wire wound along a plane.

Abstract: The polarity detection circuit includes a first diode with anode receiving a first phase of the AC power supply voltage and a second diode with anode receiving a second phase, opposite the first phase. The detection circuit further includes a constant-voltage power supply outputting a positive constant voltage. A first reference-voltage output circuit outputs a voltage corresponding to the constant voltage when the AC voltage of the first phase is positive, and outputs a voltage at a cathode of the second diode when the AC voltage of the first phase is negative. The detection circuit also includes a first signal output circuit that compares a first voltage, corresponding to a voltage at the cathode of the first diode, and a voltage output from the first reference-voltage output circuit and that outputs a signal indicative of polarity of the AC voltage having the first phase according to a comparison result.