| 摘要 |
PURPOSE:To transmit a control signal having a small number of control items in a simple circuit constitution. CONSTITUTION:A tone signal generating part 12 generates the tone signals T1-T3 with a higher frequency than a voice signal Sa. A tone signal synthesizing part 11 combines the signals T1-T3 with each other to generate a signal S1 which shows one of control contact signals C0-C7. A synthesizing part 13 synthesizes the signals S1 and Sa, and a transmission part 14 transmits the output signal of the part 13 via an antenna 15. A reception part 22 demodulates the microwaves received through an antenna 21 and outputs the signal Sa and the signal S1 including the tone signals. A filter 23 separates the signal Sa from the signal S1. A tone signal detecting part 24 detects the signals T1-T3. Then a contact signal generating part 25 outputs the control contact signals C0-C7 corresponding to the control contact signals of the transmission side with combinations of the detected signals T1-T3. |
