Abstract: A power reception device includes a power reception unit configured to receive power in a non-contact manner from a power transmission unit, and a first holding unit configured to hold the power reception unit. The power reception unit includes a power reception coil, and the power reception coil is formed by winding a first coil wire which has a width greater than a thickness thereof. The first holding unit includes a plurality of first coil holding members each formed with a first groove which extends in an extending direction of the power reception coil and receives the power reception coil. At least a part of the first groove is formed in such a way that a depth of the first groove extending in a width direction of the first coil wire is greater than a width of the first groove extending in a thickness direction of the first coil wire.

Abstract: Provided is a piezo-resistor type acceleration sensor in which an offset voltage does not fluctuate even when excessive impact/acceleration is applied. In the acceleration sensor, metal wires on top surfaces of a flexible portion and a weight are arranged in grooves formed on the flexible portion top surface/weight top surface. The acceleration sensor has a structure in which the metal wires do not hit an upper regulation plate even when the weight collides with the upper regulation plate, and the offset voltage fluctuation can be avoided.