| 摘要 |
PURPOSE:To simplify the circuit constitution of the audio signal generating circuit of a video signal generator, by generating a signal through the input buffer circuit of an amplifier and omitting a signal switching circuit, independent buffer stage, etc. CONSTITUTION:The signal generator is constituted including the buffer circuit 22 of a preemphasis amplifier 8, but when the base potential of a transistor (TR) 60 is set to the potential at which the TR60 turns on, or the potential at which the TR60 turns off, the buffer circuit 22 functions as an ordinary buffer circuit which supplies an input signal supplied from a signal source 42 to an amplifier 20. Thus, the signal generator uses the buffer circuit 22 of the preemphasis circuit 8 to generate an audio signal and also exerts no influence on the regenerated audio signal processing of an audio signal system. Further, it is evident that no signal switching circuit such as a mechanical switch to be operated externally is used, and the circuit constitution is simplified greatly. |
