| 摘要 |
PURPOSE:To reduce white noise, by utilizing the pulsed noise eliminating function to control the frequency characteristic by the white noise level. CONSTITUTION:Noise detecting circuit 9 detects noise components included in the coming stereo signal and generates a trigger pulse signal during the time of existence of noise components, and short switch circuit 10 is turned off by this signal, and noise components taken out by phase inverting circuit 2 and stereo signal stopping circuit 3 are synthesized to the stereo signal including noise by synthesizing variable resistor 5, thereby eliminating noise components. Meanwhile, when pulsed noise is not detected, switch circuit 10 is closed, and the AGC voltage in noise detecting circuit 9 controls electronic control-system variable resistance circuit 16, which is inserted to the input side of switch circuit 10, to change the frequency characteristic, thus reducing white noise. |
