| 摘要 |
PURPOSE:To afford the convenience of a user, when a sound multiplex tape is used by lighting the LED of a start to sing. CONSTITUTION:At first, a right channel signal is inputted to a presence of signal discrimination circuit 2, and decided whether a singing voice exists or not. When the singing voice exists, the signal is inputted to a one shot pulse generation circuit 3, and the circuit outputs a pulse for optional time, and lights the LED 6. Afterwards, by discriminating the trailing edge of the pulse by means of a NAND circuit 4, it lights the LED 7 of a different color from that of the LED 6. Namely, at the time of the use of the sound multiplex tape, by lighting the LED according to the presence of the right channel signal by means of using that a sound signal is recorded in the right channel signal, the display of the start to sing is performed, and the start to sing of a singer is made easy to understand. |
