| 摘要 |
PURPOSE:To improve miniaturization and to prevent to give bad influences to transmit ting and receiving devices and other electric power line carrier control equipment by the switching noise occurring from an electric power source by connecting an input end of the electric power source circuit of the logical processing part to respec tive lines of the electric wire at both sides of a low impedance circuit part and compos ing the electric power source circuit by a switching regulator. CONSTITUTION:A block filter 1 has a function to cut off a carrier frequency component between electric wires 5a and 5b. Consequently, since an impedance between the electric wires 5a and 5b to overlap a transfer signal of a carrier frequency is assured by a high impedance part A of the block filter 1, an electric power source filter 6 of a low impedance will not give bad influences to the carrier frequency on the electric wires 5a and 5b for a carrier frequency. The switching noise of the high frequency which occurs at the electric power source circuit 4 composed by the switching regulator system is attenuated by the electric power source filter 6, and after that, the neighbor hood of the carrier frequency component is further attenuated by a low impedance circuit part B, and therefore, bad influences will not be given to transmitting and receiving devices, etc., connected to the electric wires 5a and 5b. |
