| 摘要 |
PURPOSE:To perform a high-efficiency transmission with reducing loss by providing a switching means, which sets the impedance of a coupling circuit superposing the carrier output onto the transmission line such as an interior power line to a low value at a carrier transmission time and to a high value at a carrier non-transmission time, and setting the impedance of the transmission line at the view from the transmission side to a high value. CONSTITUTION:A series resonance circuit, where capacitor 4 is connected in series to secondary-side output coil 2 of coupling transformer T, in coupling circuit 1 of carrier transmitter 3 is connected between transmission lines l1 and l2 through contact r of the relay of oscillator 3a, and transmitting coil 5 is connected to the primary side of transformer T. Further, coil 5 is connected in series to driving transistor Tr1, and receiving coil 8 is connected to transformer T, and coil 8 is connected to receiving signal amplifying Tr2. Then, contact r of the relay is operated by the operation of transmission switch 6 connected to oscillator 3a, thus setting the impedance of transmission lines l1 and l2 to a low value at a transmission time and to a high value at a non-transmission time. |
