| 摘要 |
PURPOSE:To allow a master station device to transmit/receive information to/ form all slave station devices by allowing the master station device installed at a distribution sub-station to transmit an optional two-phas alternately as the reference phase of zero-phase voltage transmission. CONSTITUTION:A slave station sevice 10a takes a phase C and slave station devices 10b, 10c take a phase A as the reference phase respectively. The master station device 9 has a phase A and a phase C transmission section switching capacitors 3a, 3b to the phases A, C by using switches 4a, 4b so as to generate the zero voltage V0. Then a phase A and a phase C reception section taking multiplication outputs 8a, 8b obtained by multiplying voltages 6a, 6b of the phases A and C and the zero-phase voltage V05 obtained from the sum of the three phases at multipliers 7a, 7b as the demodulated outputs are provided. Thus, the phase A, C transmission sections and the phase A, C reception sections are used depending on the transmission/reception of the slave station devices 10b, 10c and the transmission/reception of the slave station device 10a so as to attain the transmission/reception with the slave station devices 10a-10b. |
