| 摘要 |
<p>PURPOSE: To allow a specific channel to be automatically selected and a programmed picture recording to be performed by counting the number of the calling tones of telephone required for outputting the selected data of a specific channel of the data generating section. CONSTITUTION: The signals of calling tones of telephone are amplified by the amplifier circuit 2 and impressed on the base of the transistor Q1 through a direct current interrupting condenser C1 of the resonance amplifier section 3. Then they are impressed on the clamping diodes D1, D2 through the direct current interrupting condenser C3 of the clamping section 4 to be clamped as a negative(-) voltage and to output a high-potential signal to the collector of the transistor Q2, which signal is impressed on a M-ary counter CN1 and triary counter CN2. Accordingly the flip-flop FF-1-FF3 are successively driven to output specific channel selection data (N=1, 2, 3), which are impressed on the microcomputer 7 to select a specific channel, allowing a programmed picture recording.</p> |
