| 摘要 |
PURPOSE:To simplify the constitution of a device and to realize a privacy call circuit with high performance by sampling a voice signal at the transmission and reception side of a communication system and processing the device consisting mainly of a storage circuit sampling and outputting the signal according to the clock. CONSTITUTION:A transmission voice signal from an input terminal 20 of a privacy call device is inputted to a shift register 22 consisting of a charge transfer element via an LPF21 and the input signal is sampled according to the clock. Clocks f1, f2 of clock circuits 23, 24 are fed to this register 22 via an AND gate 25 and an OR gate 26 or an AND gate 27 and the gate 26. Further, a counter circuit 28 is controlled by an output of the gate 26 and an output of the circuits 23, 24 is changed over alternately by outputs Q, Q' from the circuit 28. Further, the output Q of the circuit 28 is supplied to a variable gain circuit 33, the output of the register 22 is supplid to an adder circuit 34 inputting the output of the register 22 to simplify the constitution of the device and improve the performance of the privacy call circuit. |
