| 摘要 |
PURPOSE:To obtain an impulse detection circuit which will not execute malfunction with respect to the overlapping of impulsive noises by providing a delay circuit for an output of a noise detection circuit and controlling the inserting and separating of the provided delay circuit. CONSTITUTION:When an in-band signal is nil, an output of a comparator 3 is switched to the solid line side of a switching circuit 5. When the in-band signal exists, said output is switched to the dotted line side. The in-band signal passes through an in-band signal detector 1 and becomes a positive DC voltage. On the other hand, noise components except the in-band signal pass through a detector 2 for noise components and become positive DC voltages. If there are impulsive sounds, they are eliminated by a delay circuit 4. |
