| 摘要 |
PURPOSE: An ATT speaker system having an emergency broadcast detecting function including a damping unit is provided to be operated with a speaker arranged in various positions of a building without the connection of an additional power source line. CONSTITUTION: An ATT speaker system comprises a speaker (30), a rectifying unit (30), a wave detecting unit (60), and an attenuation unit (20). The speaker receives a sound signal output from an amplifier through an input terminal and a common terminal and outputs the received sound signal to a sound. The rectifying unit receives the sound signal by being connected to the input terminal or the common terminal in a row and rectifies the received sound signal to a predetermined a direct current (DC) voltage. The wave detecting unit is operated by the DC voltage charged in a charging unit and outputs a control signal when a predetermined waveform is detected by detecting the waveform of the sound signal generated in the input terminal. The attenuation unit is arranged between an output terminal of the amplifier and the input terminal of the speaker and controls the sound volume of the sound signal which is input in the speaker from the amplifier according to the control signal input by the wave detecting unit. [Reference numerals] (10) Amplifier; (40) Rectifying unit; (50) Charging unit; (60) Wave detecting unit; (AA) Control signal |
