| 摘要 |
<p>An electrical control system for operatively controlling and/or monitoring one or more remote power switching terminals from a master power controller terminal The power controller terminal and power switching terminal(s) are linked by a data transmission line or bus coupled to the respective terminals through D.C. isolating transformers and over which coded data signals are transmitted The coded data signals comprise coded bursts of relatively low frequency carrier signals at relatively low repetition rates and produced by an oscillator circuit which forms part of a tuned circuit at the terminal concerned which determines the carrier frequency and which includes the coupling transformer coupling the terminal to the data transmission line or bus.</p> |
