| 摘要 |
PURPOSE:To simplify circuit constitution by excluding a regulation part while converting an IF signal direct to a digital signal by detecting a difference between the output of a waveform shaping circuit and that of a monostable multivibrator and then by obtain a demodulated signal by integrating the obtained difference signal. CONSTITUTION:The output of intermediate frequency amplifying circuit 5 is applied to waveform shaping circuit 10 and at the rise of the output of circuit 10, monostable multivibrator 12 is triggered. The output time of this multivibrator 12 is set to a fixed constant time that corresponds to the half-wave period length of the output of amplifying circuit 5 and while the output of multivibrator 12 is applied to one terminal of NAND gate 11 via inverter 13, that of circuit 10 is also applied to the other terminal of gate 11 to detect the difference output between the outputs of circuit 10 and multivibrator 12. Then this difference output is integrated by integral network 15 via inverter 14 and a demodulated signal is outputted. The output of this integral network 15 is inputted to the post-stage remote control equipment that controls a chime, etc., to exclude a regulation part, so that the circuit constitution will be simplified. |
