Power generation device
A power generation device includes a coil, a magnet, and a diaphragm. The magnet is provided at a position distant from the coil, having magnet pole faces facing a direction of the coil. The diaphragm vibrates upon receiving a sound wave, having either the coil or the magnet being placed. The diaphragm generates power by generating an electromotive force in the coil by a change in a magnetic field of the coil caused by changing a relative position of the coil and the magnet by vibration.
1 . A power generation device comprising:
a coil;
a magnet that is provided at a position distant from the coil and has magnet pole faces facing a direction of the coil; and
a diaphragm that vibrates upon receiving a sound wave and has either the coil or the magnet placed thereon, wherein;
the diaphragm comprises a first diaphragm and a second diaphragm, disposed facing each other;
either one of the coil and the magnet is disposed on the first diaphragm and the second diaphragm, and
the other one of the coil and the magnet is disposed be ween the first diaphragm and the second diaphragm.
2 . The power generation device according to claim 1 , wherein a sealed space is formed with the first diaphragm and the second diaphragm.
3 . The power generation device according to claim 2 , wherein
the magnet is fixed to a fixing plate that is disposed between the first diaphragm and the second diaphragm, and
the fixing plate includes a hole part that allows the sealed space to contact both the first diaphragm and the second diaphragm to be an integrated space.
4 . The power generation device according to claim 1 , wherein the coil and the magnet are placed to be in a positional relationship where respective central axes are not aligned.
5 . The power generation device according to claim 4 , wherein a facing direction of the central axis of at least one of the coil and the magnet is different from a vibration direction of the diaphragm.
6 . The power generation device according to claim 1 , wherein the magnet is fixed to the diaphragm to be vibrable, and vibrates in association with vibration of the diaphragm.
7 . The power generation device according to claim 1 , wherein
the magnet is fixed to the first diaphragm and the second diaphragm such that the magnetic pole faces face a perpendicular direction to a vibration direction of the diaphragm, and
the coil is placed at a position opposing the magnetic pole faces of the magnet.
8 . The power generation device according to claim 7 , wherein the coil is placed at each of positions on both directions opposing the magnetic pole faces of the magnet.
9 . The power generation device according to claim 8 , wherein
the magnet is formed with a first magnet placed on one of the first and second diaphragms and a second magnet placed on the other one of the first and second diaphragms,
the first magnet is fixed to the first diaphragm such that an end part of a magnetic pole face of the first magnet opposes an end part of a magnetic pole face of one of the coils, and
the second magnet is fixed to the second diaphragm such that an end part of a magnetic pole face of the second magnet opposes an outer peripheral part of an opening face of the other one of the coils.
10 . The power generation device according to claim 7 , wherein the coil and the magnet are placed at positions where an outer peripheral part of an opening face of the coil opposes a vicinity of an outer peripheral part of a magnetic pole face of the magnet.
11 . The power generation device according to claim 1 , wherein
the magnet includes:
an annular-shaped magnet; and
a cylindrical-shaped magnet that is inserted into a circular hole of the annular-shaped magnet, and
polarities are opposite in a magnetic pole face of the annular-shaped magnet and a magnetic pole face of the cylindrical-shaped magnet facing in an identical direction.