摘要 |
In an electric alarm device, a disk-shape housing has an opening on one surface and a substantially flat bottom surface on the other surface. A diaphragm is fixed to the periphery of the housing to close the opening of the housing. An armature is mounted within the housing and coupled to the diaphragm to move with the diaphragm. A solenoid coil unit is fixed to the housing within the housing to generate magnetic fluxes for attracting the armature. A switch is mounted within the housing to detect the movement of the diaphragm to conduct and break the current to the solenoid coil unit.
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