According to one embodiment, a power control circuit includes a converter, a signal generating circuit, an estimation unit, and a controller. The converter includes a switching circuit and is configured to transform an output voltage from a power generator. The signal generating circuit is configured to transmit a signal to the switching circuit. The estimation unit is configured to determine a switching operation condition based on vibration information indicative of a vibration applied to the power generator. The controller is configured to control an operation of the switching circuit based on the determined switching operation condition.

A measurement system includes: a vibration-driven energy harvesting unit that generates electric power from sound, vibration, or displacement; a power supply controller that controls an amount of power consumption of a power supply based on the electric power generated by the vibration-driven energy harvesting unit; a detector that is driven by electric power supplied by the power supply controller and detects an environment state quantity; and a transmitter that is driven by electric power supplied by the power supply controller and transmits information regarding the environment state quantity detected by the detector.

A secondary battery may include an electrode assembly formed by alternately stacking an electrode and a separator; a battery case; a plurality of electrode tabs, each of which protrudes from the electrode assembly; a plurality of electrode leads, each of which has one end connected to the electrode tab and the other end protruding outward; a piezoelectric element which is disposed to the outside of a cup portion of the battery case that accommodates the electrode assembly and which, when the battery case expands in volume, receives pressure and supplies electric power to the outside; and a short-circuit inducing part which has a wire shape and both ends respectively positioned on sealing portions of the battery case that seal the electrode leads, wherein, when the electric power is applied from the piezoelectric element, both the ends respectively extend toward the electrode leads and come into contact with the electrode leads.

A frame for an energy transducer device for generating electrical current, the frame being a single monolithic structure including a pressure receiver unit, a first arm and a second arm joined to respective lateral sides of the pressure receiver unit, a first attachment unit joined to the second end of the first arm, and a second attachment unit joined to the second end of the second arm. The frame is configured to be joined to a current generating unit, such that the first attachment unit is joined to a first edge of the current generating unit while the second attachment unit is joined to second edge of the current generating element. An external force applied at the pressure receiver unit of the frame causes the frame to deform and thereby change the mechanical strain of the current generating element.

A frame for an energy transducer device for generating electrical current, the frame being a single monolithic structure including a pressure receiver unit, a first arm and a second arm joined to respective lateral sides of the pressure receiver unit, a first attachment unit joined to the second end of the first arm, and a second attachment unit joined to the second end of the second arm. The frame is configured to be joined to a current generating unit, such that the first attachment unit is joined to a first edge of the current generating unit while the second attachment unit is joined to second edge of the current generating element. An external force applied at the pressure receiver unit of the frame causes the frame to deform and thereby change the mechanical strain of the current generating element.

[Object] To provide a technology such as a piezoelectric coil having higher energy conversion efficiency.

[Solving Means] A piezoelectric coil according to the present technology includes a coil-like core material and a plurality of band-like piezoelectric materials. The plurality of piezoelectric materials is helically wound around the core material so as to be alternately arranged along the core material.

A device is disclosed, which includes: a charge portion with a plurality of piezoelectric elements embedded in a tire configured for a vehicle, a capacitor mechanically coupled to the tire and electrically coupled to the plurality of piezoelectric elements; a transmitter coil, mechanically coupled to the tire and electrically coupled to the capacitor through a discharge portion; wherein in response to an external radial pressure on the tire resulting from movement of the vehicle which causes a pressure on the plurality of piezoelectric elements, the plurality of piezoelectric elements produce an electrical charge on the capacitor, and wherein the discharge portion electrically connects the electrical charge on the capacitor to the transmitter coil to send electromagnetic power to the vehicle.

A device is disclosed, which includes: a charge portion with a plurality of piezoelectric elements embedded in a tire configured for a vehicle, a capacitor mechanically coupled to the tire and electrically coupled to the plurality of piezoelectric elements; a transmitter coil, mechanically coupled to the tire and electrically coupled to the capacitor through a discharge portion; wherein in response to an external radial pressure on the tire resulting from movement of the vehicle which causes a pressure on the plurality of piezoelectric elements, the plurality of piezoelectric elements produce an electrical charge on the capacitor, and wherein the discharge portion electrically connects the electrical charge on the capacitor to the transmitter coil to send electromagnetic power to the vehicle.

A smart ring is configured harvest mechanical energy using piezoelectricity. The smart ring includes a ring-shaped housing, a power source disposed within the ring-shaped housing, and a charging circuit. The charging circuit includes a piezoelectric harvesting element, and is configured to charge the power source when user motion causes a mechanical deformation in the piezoelectric harvesting element. The smart ring further includes a component, disposed within the ring-shaped housing and configured to draw energy from the power source, and further configured to perform at least one of: i) sense a physical phenomenon external to the ring-shaped housing, ii) send communication signals to a communication device external to the ring-shaped housing, or iii) implement a user interface.

A smart ring is configured harvest mechanical energy using piezoelectricity. The smart ring includes a ring-shaped housing, a power source disposed within the ring-shaped housing, and a charging circuit. The charging circuit includes a piezoelectric harvesting element, and is configured to charge the power source when user motion causes a mechanical deformation in the piezoelectric harvesting element. The smart ring further includes a component, disposed within the ring-shaped housing and configured to draw energy from the power source, and further configured to perform at least one of: i) sense a physical phenomenon external to the ring-shaped housing, ii) send communication signals to a communication device external to the ring-shaped housing, or iii) implement a user interface.