| 摘要 |
<p>D.C. power is transmitted from a station lift of the line L to a distant consumer right of the line L over two conductors, (1, 2) which are at the same time used to transmit information. The d.c. source (3) supplies the power and a switching transistor (6), controlled by a pilot transistor (7) superimposes square pulses on the d.c. across the resistor (4). The receiver station includes an a.c./d.c. converter (9) and a d.c./a.c. converter (8). The modulation frequency of the information signal is recovered by an amplitude demodulator (10) consisting of an optucoupler (11). This is controlled by a pulse amplifier (12, 14, 15, 16). A trigger (18) feeds the output to a discriminator (19).</p> |
