| 摘要 |
PURPOSE:To attain simplicity of a radio equipment and low power consumption by allowing the changeover of an input terminal selecting changeover switch and a feedback loop selection changeover switch to output a signal compressing or expanding a dynamic range of voice signal. CONSTITUTION:When the titled circuit is used as an expander, the input terminal selection changeover switch 19 and the feedback loop selection changeover switch 20 are connected in solid lines in the figure, a compression signal where the dynamic range of the voice signal is compressed to 1/2 is inputted to a 1st voice signal input terminal 14 and the voice signal where the dynamic range of the said input signal is expanded to twice and the signal is restored to the original voice signal is outputted from a 2nd voice signal output terminal 16. In using the circuit as a compressor circuit, the switches are thrown in dotted lines in the figure, and the dynamic range of the voice signal inputted to a non-inverting input of an operational amplifier 21 from a 2nd voice signal input terminal 15 is compressed to 1/2 and the result is outputted from a 1st voice signal output terminal 18. |
