| 摘要 |
PURPOSE:To constitute a high impedance to one carrier signal frequency and a low impedance to another signal frequency, by providing a control range split block filter at both sides of the control range, in a power line carrier transmission system. CONSTITUTION:A commercial power supply is supplied to an indoor power line 2, control areas A1, A2 are provided with a transmitter 1 and a receiver 3, and control range split block filters 51, 52... are provided between the control areas. In the filters 51, 52..., elements Z1, Z2 being high impedance to a frequency f1 of the carrier signal are connected in series and an element Z3 being low impedance to the frequency f1 constitutes a T type filter with the elements. The carrier signal in the frequency f1 for narrow band control used in the control areas A1, A2 is blocked outside the control area A1 or A2 with a control area split block filter 5, no interference is caused at the control areas A1, A2, and the signal is not limited at the filter 5 by using other frequency f2, allowing to use wide area control. |
