| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent a transmission signal output from becoming excessive and producing waveform distortion, wherein the transmission signal output is sent out from a speech IC connected to the output side of a transmitter to a line. SOLUTION: A transmission distortion preventing circuit 40 is connected in parallel to a speech IC 30 connected to the output side of a transmitter 20. The transmission distortion preventing circuit 40 detects a transmission signal output from the speech IC 30. If the output is an excessive sound input established beforehand, the circuit closes a switch and reduces input impedance of the speech IC 30 to hold down the transmission signal output sent out from the speech IC 30 to a line 35 at a proper level where waveform distortion does not occur. COPYRIGHT: (C)2008,JPO&INPIT
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