| 摘要 |
PURPOSE:To increase the range of audio frequency of human beings by driving an output circuit by means of a stable signal generated by integrating the output of a lock state detection circuit included in a PLL circuit. CONSTITUTION:Detecting the presence or absence of the output V2 of a loop filter 11c can determine whether or not a PLL circuit 11 is locked. A lock state detection circuit 11d is included in the circuit 11. When the lock state detection circuit 11d detects the lock state of the circuit 11, a detection signal is entered to each counting circuit. A different mobile frequency and a different capture range within the range of audio frequency are preset in a VOC 11b in the circuit 11 for the light flashing block of each channel. A lock state is thus detected within a different frequency, the output signal is integrated by a time constant circuit, and the integration signal uses a stabilized signal to drive an output circuit to turn on each light. Then, lights can be flashed according to the different frequency ranges of different signals entered, so that the range of audio frequency of human beings is increased. |
