| 摘要 |
799,666. Signaling over power circuits. LANDIS & GYR AKT.-GES. Oct. 14, 1954 [Oct. 14, 1953], No. 29645/54. Drawings to Specification. Class 40 (4). In an arrangement for superposing on a power line signal voltages of a desired mean transmission frequency within the audio range, the audio-frequency generator is coupled to the power network by a coupling circuit comprising two inductively coupled resonant circuits both tuned to the said mean frequency and each having a single inductor, the two inductors being mutually coupled. The application of the invention to series and shunt injection and to three-phase networks is described, and the advantage of a filter giving the normal doublehump characteristic whereby the injected voltage is increased if the frequency drafts from the desired frequency is referred to. |
