. The Bell System technical journal . * i^ j w .■- » * Fig. 16—Sequence switch. Fig. 16 shows a sequence switch that has been used in the arrange-ments of both Fig. 14 and Fig. 15. With it a great many arrangementsof automatically controlled equipment may be set up besides thosedescribed, permitting the oscillographs to be used in many differentways. A modification of the continuous-film oscillograph which appears tohave some novel and useful features is shown in Fig. 17. It is adapted ^MAGAZINES Q 7 SLOW / APERTURE-A. Fig. 17—Schematic drawing of sampling oscillograph.
. The Bell System technical journal . * i^ j w .■- » * Fig. 16—Sequence switch. Fig. 16 shows a sequence switch that has been used in the arrange-ments of both Fig. 14 and Fig. 15. With it a great many arrangementsof automatically controlled equipment may be set up besides thosedescribed, permitting the oscillographs to be used in many differentways. A modification of the continuous-film oscillograph which appears tohave some novel and useful features is shown in Fig. 17. It is adapted ^MAGAZINES Q 7 SLOW / APERTURE-A. Fig. 17—Schematic drawing of sampling oscillograph. This oscillograph recordsone wave out of a number at regular intervals, say one cycle in sixty, with considerableresolution in order to record slow variations in wave form. especially for sampling a wave at regular short intervals instead ofmaking a continuous record or merely a record of unusual disturbances. 386 BELL SYSTEM TECHNICAL JOURNAL It involves, in addition to the usual optical system and means foradvancing the film, an additional mirror in the light path between thevibrator and the film, rotating synchronously with the current orvoltage to be recorded, about an axis perpendicular to both the direc-tion of motion of the film and the axis of the vibrator mirror. Thefunction of the rotating mirror is to sweep the light beam along theoscillograph film past an aperture A in such a way that the efifectivefilm speed during exposures is many times the actual film speed, andto permit of exposure during only a small part of the t
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
