| 摘要 |
<p>619,217. Repeating systems. COMPAGNIE GENERALE D'ELECTRICITE. Aug. 8, 1945, No. 20371. Convention date, Dec. 4, 1944. [Class 40 (iv)] [Also in Groups XXXVI and XL (c)] To locate a fault in series-connected amplifiers, each is in parallel with a tuned circuit, and by reversal of line current the amplifiers oscillate so that when a fault occurs in one of the amplifiers it fails to oscillate and can be located by examining the characteristics of the group as a whole. The amplifiers comprise valves 1, 2, 3 whose filaments are heated by line current and whose anode and grid potentials are also supplied by line current over rectifiers C1 ... C4, so that the amplifier operates irrespective of the direction of current in the line. Each amplifier is bridged by a characteristically tuned circuit R, L and a uni-directional conductor D, so that when the current in the line is reversed, the amplifiers oscillate. If one amplifier is faulty, not only does it fail to oscillate, but it breaks the chain, so that the line delivers only those frequencies developed by the amplifiers to one side of the faulty amplifier, and an analysis of the line output enables the location of the faulty amplifier to be determined.</p> |
