| 摘要 |
PROBLEM TO BE SOLVED: To provide an active silencing device suitable for reducing noise of pole transformers.SOLUTION: An active silencing device includes: a tunnel-like cover body 5 which covers a pole transformer 1; a silencing speaker 2 located in one side opening region 5a of the cover body 5 with a vibration radiating surface thereof facing the inside of the cover body 5; a reference signal acquisition unit 3 which acquires an induced current from an electric line of the pole transformer 1 by electromagnetic induction, as a reference signal; an error microphone 4 located on the another side opening region of the cover body 5; and an electronic control unit 6 which generates a speaker drive signal for letting the silencing speaker 2 radiate sound in antiphase with noise using the reference signal, and optimizes the speaker drive signal to reduce the noise using the detection signal from the error microphone 4. |
