| 摘要 |
PURPOSE:To prevent noise from being transmitted as receiving data signals by providing a circuit, which detects carrier breaking in a time shorter than the carrier breaking detection time of a carrier detection circuit, in the receiving data signal generator circuit of the MODEM for data communication. CONSTITUTION:After the modulated wave signal from receiving input terminal 1 is received by receiving circuit 2, this modulated wave signal is sent to carrier detector circuit 3, demodulator circuit 4 and the second carrier detector circuit 6, which has a carrier breaking detection time shorter than the carrier breaking detection time of carrier detector circuit 3, respectively. Then, logical operation circuit 5a takes out the carrier detection signal of carrier detector circuit 3 and the DC binary signal taken out from the modulated wave signal by demodulator circuit 4, namely, the receiving data signal and the carrier detection signal of the second carrier detector circuit 6 as an AND of them, and this output is defined as a receiving signal. |
