| 摘要 |
PURPOSE:To decrease the number of input and output terminals by generating the 1st and 2nd switching signals when a single control input signal enters into a prescribed state, and performing switching control. CONSTITUTION:A Dolby encoder 1 which is placed in mode B, mode C and off mode by the 1st, 2nd and 3rd switching control signals (a), (b) and (c) respectively consists of a spectral skewing (SS) circuit 2, subsidiary signals paths 6 and 16 for HLS and LLS, and a saturation preventing circuit 15. A recording input signal inputted to the SS circuit 2 is applied through the encoder 1 to a deck 28, whose playback signal is outputted through a decoder 29. According to the potential relation between the reference voltage at a connection point J2 and a control input signal voltage VS, a switching control signal generating circuit 34 generates the switching control signals (a), (b) and (c) to place the encoder in prescribed mode. |
