OSCILLOGRAPHS 



385 



to each record has been used, the line-relay will remain operated and 

 the film will continue to be exposed during one whole cycle of the 

 sequence switch. Thus a continuous record can be made of any 

 disturbance, however long, provided there is sufificient film. 



* 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 arrangements 

 of automatically controlled equipment may be set up besides those 

 described, permitting the oscillographs to be used in many different 

 ways. 



A modification of the continuous-film oscillograph which appears to 

 have some novel and useful features is shown in Fig. 17. It is adapted 



^MAGAZINES 



Q 



7 



SLOW SPEED 

 SYNCHRONOUS .MOTOR 



/ 



APERTURE -A 



Fig. 17 — Schematic drawing of sampling oscillograph. This oscillograph records 

 one wave out of a number at regular intervals, say one cycle in sixty, with considerable 

 resolution in order to record slow variations in wave form. 



especially for sampling a wave at regular short intervals instead of 

 making a continuous record or merely a record of unusual disturbances. 



