GB349543A - Means for the synchronous driving of sound and picture apparatus - Google Patents

Abstract

349,543. Synchronism indicators. KœCHENMEISTER, H. J., 1, F³rtherstrasse, Berlin. Nov. 23, 1929, No. 35961. Convention date, Nov. 23, 1928. Void [Published under Sect. 91 of the Acts]. [Class 40 (iii).] Kinematograph apparatus and sound-recording or reproducing apparatus are driven by separate continuous-current motors which are energized from a common source. The armature of each motor is tapped at two points, 180‹ apart, which are connected to slip rings on which brushes bear, corresponding brushes of the two motors being connected by leads. This arrangement serves to keep the motors running in synchronism. The motors, which are shunt-wound, have their armatures connected in parallel, and are controlled by a common regulating resistance. In the system shown, the field windings b, b<1>, of two motors are connected to a source of current c through a common resistance d. A separate regulating resistance e is also provided in series with the winding b<1>. The windings of each armature a, a<1> is tapped at two points, 180 electrical degrees apart, and the corresponding points on the two armatures are connected through slip rings k, brushes, and leads g, g<1>. The two pairs of leads are joined by a double-pole switch h, in parallel with which are two lamps i, i<1>. When the switch is opened and the motors are started, the lamps flicker unless the motors are in synchronism. By adjusting the resistance e, the speeds of the two motors are equalized, this condition being indicated when the lamps cease to flicker. When the proper adjustment has thus been made, and the lamps are extinguished, the switch h is closed, and synchronism is thereafter maintained automatically.