An alarm system includes one or more audio stations, and an audio station network interface. The electrode layers define a middle segment in an interior of the piezoelectric layers and end segments located between ends of at least some of the electrode layers and an end of at least one of the piezoelectric layers. The inverter apparatus includes a metal plate secured in an inverter storage box, a plurality of power semiconductor switching elements mounted on the metal plate, a power substrate on which a power-related control circuit for operating the power semiconductor switching elements is mounted, and a busbar assembly formed by integrating a plurality of busbars with an insulator. The reception unit receives the satellite signal during the signal period in which the time-related information part can be received, and does not receive the satellite signal during the signal period in which the satellite information part can be received.