Abstract: A sound generator that generates sound by vibrating a diaphragm includes: a housing including a first space opened to the atmosphere by a sound emission hole and a second space separated from the first space by the diaphragm; and a shield plate disposed in the first space to face the diaphragm while being separated from the diaphragm. When the diaphragm is displaced toward the first space by a pressure difference between the first space and the second space, the diaphragm comes in contact with the shield plate to limit deformation of the diaphragm.

Abstract: An electromagnetic relay includes a base frame including a main body supporting a fixed element, and a bottom plate having a plate thickness direction in an extending direction orthogonal to a central-axis line direction. An intermediate cover includes a covering plate facing a contact mechanism unit. An outer cover includes a top plate facing the bottom plate across the contact mechanism unit, and a first side plate extending from one end of the top plate and facing the covering plate. A first gap between the covering plate and the bottom plate in the extending direction and a second gap between the covering plate and the top plate in the extending direction are arranged to be substantially symmetric across the covering plate in the extending direction, the first gap and the second gap being on the first side plate.

Abstract: A contact point device includes a first contactor, an oscillation supporting portion, and a second contactor. The first contactor has an outer side surface shaped in a column that surrounds a central axis. The oscillation supporting portion supports the first contactor to allow the central axis to oscillate. The second contactor is disposed opposite to the first contactor. One of the first contactor and the second contactor includes a plurality of first contact portions provided to surround the central axis on a plane perpendicular to the central axis, and the other includes a second contact portion provided to protrude toward a space surrounded by the plurality of the first contact portions. The second contact portion has a contact surface which is a curved surface exposed toward the space to surround the central axis.

Abstract: A stationary core is in an exciting coil. A yoke covers an outer periphery and an axial end of the exciting coil to form a magnetic circuit and has an opening portion. The movable core faces the stationary core through the opening portion and is attracted toward the stationary core on energization of the exciting coil. A return spring urges the movable core against the attraction direction. A first gap is formed between the stationary core and the movable core on deenergization of the exciting coil. A second gap is formed between the yoke and the movable core on deenergization of the exciting coil. The second gap allows the yoke and the movable core to generate an attractive force therebetween on energization of the exciting coil. The return spring is made of a magnetic material to magnetically bridge the first gap or the second gap.

Abstract: An overcurrent protection device is to be provided between a power supply and a load circuit including an electric load and an electric wire electrically connected with each other, and includes a switching element, a current detector, a characteristic estimation portion, and a controller. The switching element switches flowing and interrupting of a load current that flows from the power supply to the electric load. The current detector detects the load current. The characteristic estimation portion estimates a thermal characteristic of the electric wire based on the load current detected by the current detector. The controller outputs an overcurrent protection signal for interrupting the load current so as to protect the load circuit from an overcurrent to the switching element based on the thermal characteristic estimated by the characteristic estimation portion and the load current detected by the current detector.

Abstract: An electromagnetic relay includes: an excitation coil; a movable core; a movable contactor that operates by following the movable core; a fixed contactor that is in contact with the movable contactor when the excitation coil is energized; a base that supports the fixed contactor; a fixed yoke fixed to the base; a moving yoke; a first pressing spring that biases the moving yoke toward the movable contactor; and a second pressing spring that biases the movable contactor such that the movable contactor and the fixed contactor are in contact with each other. The moving yoke is disposed to be in contact with a surface of the movable contactor opposite from the fixed contactor and to oppose the fixed yoke through the movable contactor. The moving yoke is provided to be able to contact and separate from the movable contactor.

Abstract: An electromagnetic relay includes a mobile component movable at time of energization and de-energization of a coil, and a fixed component immovable at the time of energization and de-energization of the coil. A damping space is provided between the mobile component and the fixed component and changes in volume with the movement of the mobile component. A gap provided between the mobile component and the fixed component serves as a passage that allows gas to flow into or out of the damping space when the damping space changes in volume. A size of the gap is set such that a pressure is generated in the damping space to cause a damping force acting on the mobile component when the damping space changes in volume.

Abstract: A piezoelectric sounding element includes a diaphragm made of metal and a piezoelectric element provided on at least one surface of the diaphragm. A non-fixed portion of the diaphragm includes the pair of long sides facing each other, a pair of short sides, shorter than the long sides, that face each other, and a pair of recesses, provided in the pair of long sides, that protrude so as to approach each other. The piezoelectric element is provided in a region between the pair of recesses of the diaphragm and the contour shapes of the non-fixed portion of the diaphragm and the piezoelectric element are defined so as to be symmetric with respect to a first imaginary line that bisects the pair of short sides and symmetric with respect to a second imaginary line that bisects the pair of long sides.