| 摘要 |
PURPOSE:To improve the injection efficiency and to reduce the size of a commercial frequency cutting capacitor to make the whole of a device small in size, by connecting a series resonance circuit, which resonates to a prescribed frequency between a power line and the output of a transmitter which superposes a carrier signal having the specified frequency onto the power line and transmits it. CONSTITUTION:The output signal of an oscillator 6 which generates the carrier signal having the prescribed frequency is amplified by an amplifier 7, and this carrier signal is superposed onto a power line 12 having a commercial frequency by an output transformer 8. A series resonance circuit 11 which resonates to the prescribed frequency is connected between the secondary side of the output transformer 8 and the power line 12, and the resonance circuit 11 consists of a coil 9 and a capacitor 10. The impedance of the resonance circuit 11 is made smaller than the output impedance in the secondary side of the output transformer 8, and the overall output impedance is made equal to the impedance of the power line 12, thus improving the injection efficiency to the power line 12 and making the capacitor 10 small in size. |
