Alarm device, electric wire anti-theft device and electric wire anti-theft system

摘要

To provide an alarm device which generates a warning by detecting disconnection of a wire and can issue an alarm with a simple structure.SOLUTION: The alarm device comprises a first power supply means 11A for supplying a first current Ia to a lead wire, a sound generation means 12 for generating an alarm, a second power supply means for supplying a second current Ib to the sound generation means 11B and a switch means 14 which is turned on / off in accordance with the first current or the second current, the first power supply means is connected to the ground via a conductor, the conductor is disconnected The second power supply means is connected to the switch means via the sound generation means, and when the first power supply means supplies the current to the switch means, the sound generation means supplies the current to the switch means, A current is supplied from the second power supply means to be in a conducting state, and the sound generating means sounds.(FIG.