| 摘要 |
PURPOSE:To lower noise at a low cost by providing switchover control means for connecting a noise detecting/converting means and a sound generating means to a suction duct at the time of an inner air mode while connecting the noise detecting/converting means and sound generating means to a blow-out duct at the time of an outer air mode. CONSTITUTION:A microphone 11 (a noise detecting/converting means) is provided via a microphone switchover device 10 (a first switchover means) while providing a speaker 16 (a sound generating means) via a speaker switchover device 15 (a second switchover means). When an air conditioner is in an inner air mode, since noise is larger in a suction duct 9 than in a blow-out duct 3, both switchover devices 10, 15 are controlled by a microcomputer to connect the microphone 11 and speaker 16 to the duct 9. At the time of an outer air mode, the microphone 11 and speaker 16 are connected to the duct 3. The phase characteristic of the microphone 11 is controlled according to the electric signal thereof by means of a control circuit to give force a sound in the opposite phase to noise, out of the speaker 16. |
