摘要 |
<p>A transmission arrangement includes a switched resonant circuit (5) for switching data states of digital signals on a pair of transmission lines (1, 2) and a regenerative circuit (7) for feeding power back on the lines. The switched resonant circuit has a switching device (22) connected in series with an inductance (20) and parallel with a capacitance (21). A digital logic system (8) controls the switching device such that switching occurs at a line current zero crossover point. Where a change of data state is to be transmitted to a receiver (6), the logic system (8) turns the switching device on at an appropriate time. The switching device is switched off when the voltage (+Vm) on the lines reaches approximately the same magnitude in the opposite sense (-Vm). The change in the line voltage indicates a change of the data state to the receiver.</p> |