基本信息
摘要：1,248,211. Wave-energy distance measuring; automatic phase control. THOMSON-CSF. 25 Oct., 1968 [31 Oct., 1967], No. 50842/68. Headings H3A and H4D. In relative phase determining apparatus, a signal of unknown phase is compared in a phase comparator 6 with a signal from a mixer 5 and the comparator output controls the frequency of a variable frequency oscillator 2, the inputs to mixer 5 being the output of a mixer 3-fed with the outputs of oscillator 2 and a fixed frequency oscillator 1-and an output from oscillator 2 as delayed by line 4. The invention is applied to measuring the distance d of a target 10, the transmitted waves being radio, acoustic or light. The measuring wave may be amplitude modulated on to a higher-frequency wave, e.g. a semi-conductor visible or invisible light source, Fig. 2 (not shown). The arrangement may be extended for higher precision over greater distances, utilizing two fixed, and two variable, frequency oscillators, Fig. 3 (not shown).
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