Abstract: Disclosed herein is a coil component that includes first, second, third, and fourth terminal electrodes; a first planar spiral coil formed on a substrate, the first planar spiral coil having an outer peripheral end connected to the first terminal electrode; a second planar spiral coil stacked on the first planar spiral coil through a first insulating layer, the second planar spiral coil having an outer peripheral end connected to the second terminal electrode; and first and second lead-out patterns stacked on the second planar spiral coil through a second insulating layer. The first lead-out pattern connects the third terminal electrode and an inner peripheral end of the first planar spiral coil. The second lead-out pattern connects the fourth terminal electrode and an inner peripheral end of the second planar spiral coil. The second insulating layer is thicker than the first insulating layer.

Abstract: Disclosed herein is a coil component that includes an element body having a mounting surface, a coil pattern embedded in the element body and having a coil axis extending perpendicular to the mounting surface, and a terminal electrode connected to the coil pattern and exposed to the mounting surface. The terminal electrode has a cutout part so as to avoid overlapping with the coil pattern in a plan view along the coil axis.

Abstract: Provided is a power generation device that restrains interference between a plurality of flows of alternating current power if the flows of alternating current power are generated in the power generation device. The power generation device includes a housing, a first power generator held in the housing so as to be allowed to vibrate, and a second power generator held in the housing so as to be allowed to vibrate. The second power generator is electrically isolated from the first power generator.

Abstract: A power generation device includes a holder with a natural frequency of fA, and two or more vibration energy harvesting elements held by the holder and having natural frequencies different from each other. Out of the vibration energy harvesting elements, one has the lowest natural frequency fBmin satisfying the following Expression 1, and another one has the highest natural frequency fBmax satisfying the following Expression 2: fBmin?(0.925?2.5 N/100)fA??(1), and fBmax?(1.075+2.5 N/100)fA??(2), where N is the number of the vibration energy harvesting elements.

Abstract: Disclosed herein is a bridge abnormality sensing device including: a pair of vibration sensors installed in an upper structure of a railroad bridge supported with a plurality of bearings, the pair of vibration sensors being provided for two of the bearings arranged in a width direction; a detector circuit configured to output a damage detection signal based on a difference between output signals of the pair of vibration sensors; and an output circuit configured to receive the damage detection signal and notify an external device of any structural damage detected from the railroad bridge. The vibration sensors are vibration power generators that generate power in a frequency range of abnormal vibration resulting from the damage. Power to drive the detector circuit is supplied from the vibration power generators.

Abstract: A power generator including: a first vibration system in which a first mass member is elastically supported by a first spring member; and a second vibration system in which a second mass member is elastically supported by a second spring member, the first and second vibration systems providing a multiple-degree-of-freedom vibration system. A power generating element disposed between the first and second mass members is configured to convert vibration energy input to the first vibration system and the second vibration system from a vibrating member to electrical energy. A resonance frequency of the first vibration system is a frequency lower than 1/?2 times a frequency of a vibration input to the first vibration system from the vibrating member. A loss factor of the first spring member of the first vibration system is at least 0.01 but not greater than 0.2.