| 摘要 |
PURPOSE:To cause the difference of output levels before and after switching to be practically zero and to prevent a discontinuous part from generation, which becomes noise on auditory feeling, by generating a signal, which changes over an analog switch group, at the almost zero cross point of a reproducing signal from a source. CONSTITUTION:The reproducing signal from a source 1 and a standby signal (STB) from a control part 5 are inputted to a strobe generating part 11 and a strobe signal ST is generated at the zero cross point of the reproducing signal. For example, a strobe generating part 114 is composed of a two-input AND circuit. Then, the output of an EX-OR circuit 112a is connected to one input and an output Q of an RS-FF part 113 is connected to the other input respectively. When the both inputs go to an H level by the operation of an AND circuit 114, the output goes to be the H level and the strobe signal (ST) is generated. Accordingly, the discontinuous part before and after the changing-over of the analog switch group can be reduced infinitely and the noise on the auditory feeling can be erased. |
