| 摘要 |
<p>PURPOSE:To provide an electronic noise eliminator for which ensures noise eliminating effect of an electronic noise eliminating system even in a high-speed blower pipe. CONSTITUTION:A blower pipe 1 has a noise eliminating pipe passage portion 1a, with the pipe passage sectional area S2 larger than the pipe passage sectional area S1 of the blower pipe 1, provided on its way, so that sound waves transferred from a noise source may be decelerated in the noise eliminating pipe passage portion 1a and detected by the first microphone 2 and sound waves in the opposite phase of and at the same pressure as the transferred sound waves may be generated by a controller 4 from a speaker 5 arranged downstream of the first microphone to eliminate transferred sound waves through the interference of sound waves downstream of the speaker 5. In this way, an S/N of the first microphone is ensured and sufficient noise eliminating effect is achieved.</p> |
