| 摘要 |
752,558. Automatic frequency control systems. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Jan. 14, 1954 [Jan. 17, 1953], No. 1118/54. Addition to 687,602. Drawings to Specification. Class 38 (4). In a modification of the control system of the parent Specification, in which pulses derived from the controlled generator are applied to open a one-way conductor, biased by a threshold voltage, to master control oscillations normally in quadrature phase applied to its tuned circuit, a rectifier is inductively connected with the master oscillator in the threshold voltage circuit so as to allow a decrease of the D.C. threshold voltage partly due to this rectifier when the master oscillator is under increasingly high load due to increased mistuning of the tuned circuit of the controlled oscillator, and thereby counteract voltage variations of the threshold voltage and master oscillator and extend the holding range of the system. The master oscillator may be coupled to one or more control circuits through an impedance inverting network. |
