| 摘要 |
1,020,375. Phase detectors. COMPAGNIE D'APPLICATIONS MECANIQUES A. L'ELECTRONIQUE, AU CINEMA ET A L'ATOMISTIQUE (CAMECA). April 13, 1964 [April 17, 1963], No. 15277/64. Heading H3A. A synchronous detection circuit comprises two double triode circuits associated to provide an output signal practically independent of the local signal amplitude. In Fig. 4 a signal S is applied to grids g 1 and g 1 <SP>1</SP> of the two doubletriodes and its inverse - S is applied to grids g 2 and g 2 <SP>1</SP>. A square wave M of the same frequency as S is applied to grids g 1 and g 2 <SP>1</SP> and its inverse - M is applied to grids g 2 and g 1 <SP>1</SP>. The output across R 4 , after smoothing in a filter (not shown), is shown to be proportional to #M+ÁS cos #, where # is the phase of S and # and Á are circuit constants. Similarly the output across R<SP>1</SP> 4 is #<SP>1</SP>M - Á<SP>1</SP>S cos #, and the difference equals (Á + Á<SP>1</SP>)S cos #+(#-#<SP>1</SP>)M. Since # is nearly equal to #<SP>1</SP> this difference output Vd is much less sensitive to variation of M than the output across R 4 . |
