| 摘要 |
<p>1,114,118. Automatic frequency control systems. COMPAGNIE FRANCAISE THOMSON - HOUSTON - HOTCHKISS BRANDT. 6 July, 1965 [8 July, 1964], No. 28679/65. Heading H3A. [Also in Division G4] An automatic frequency control system wherein an oscillator 11, Fig. 1, feeds a divider 12 to provide an input to discriminator 13 at the same frequency as a reference oscillator 15, is characterized in that the division ratio of divider 12 is set by electronic switches which may be controlled by a digital input signal. This input signal may be fed via a series-parallel converter (25, Fig. 2, not shown) to control three triggers (241-243) which in turn control three electronic changeover switches (221-223) controlling a three-stage binary counter (211- 213) and a re-setting AND gate (23). The A.F.C. loop may include a search oscillator 17 acting on the variable reactance 14 controlling the frequency of oscillator 11.</p> |
