Abstract: A sound source device of a horn according to one aspect of the present invention includes: a diaphragm; a movable iron core connected to the diaphragm through a support point; and a coil (bobbin and winding) into which a driving signal is inputted. The driving signal includes a first signal component that resonates with the diaphragm and a second signal component of a second frequency that resonates with the movable iron core of a first frequency and has a chord relationship with the first frequency. The support point is provided at a position eccentric from the center of the diaphragm, and the movable iron core is structured such that a gravity center is displaced further in an eccentric direction than the support point.

Abstract: A sound source device of a horn according to one aspect of the present invention includes: a diaphragm; a movable iron core connected to the diaphragm through a support point; and a coil (bobbin and winding) into which a driving signal is inputted. The driving signal includes a first signal component that resonates with the diaphragm and a second signal component of a second frequency that resonates with the movable iron core of a first frequency and has a chord relationship with the first frequency. The support point is provided at a position eccentric from the center of the diaphragm, and the movable iron core is structured such that a gravity center is displaced further in an eccentric direction than the support point.

Abstract: An impeller for use in a centrifugal blower comprises a hub for receiving a driving torque at a central portion thereof, a shroud of a ring-like shape in plane formed with an opening for air intake at the center thereof and opposed to the hub across a required distance therebetween, and a plurality of vane members interposed between the hub and shroud as circumferentially spaced from one another at required intervals, the impeller having an arrangement wherein an leading edge of each vane member has varied angles (inlet angles) with respect to a tangent line thereat thereby conforming to inflow angles of an air flow guided by the vane member at different points of a span between the shroud and hub.

Abstract: A number of vanes 12 are disposed in a peripheral direction of a plurality of supporting disks disposed along a rotary shaft 14 at given intervals. Each vane 12 is disposed at an angular interval as determined by a logistic representation. Thereby the intensity and variations of noise levels at around 8N on the low-frequency side, as well as the noise level caused by rotary first-order sounds, can be reduced.