GB428041A - Improved method and apparatus for the automatic synchronisation of rotary movements and their application to the transmission of images - Google Patents

Abstract

428,041. Maintaining defined speeds of motors. MUTUELLE MOBILIERE SOC. ANON., 4, Rue Montoyer, Brussels. Aug. 4, 1933, No. 21976. Void [Abridged as open to inspection under Sect. 91 of the Acts, Feb. 9, 1934]. [Class 38 (iii)] [See also Group XL] A synchronizing signal acts on an oscillator 14 in a speed governor to vary the speed of a motor 7 when out of synchronism. The synchronizing signals in the coil 14 oscillate it to open a contact 9 and close a contact 26. At synchronism a resistance 4 in the circuit of the motor remains short-circuited through brushes 16, 17 on segments 18, and a resistance 5 remains in circuit through brushes 27, 28 being off segments 29. The supply to the motor is thus unchanged. If the motor is in advance, brushes 16, 17 are no longer in contact with the segments 18 when the contact 9 is opened, and the resistance 4 is switched in circuit to retard the motor. If, on the contrary, the motor lags, the resistance 5 is short-circuited through the brushes 27, 28 being in contact with the segments 29, and the motor accelerates. According to modifications: the resistances or chokes 4, 5 are in shunt with the field of a shunt-wound motor, Fig. 3 (not shown), or in series with the armature, Fig. 4 (not shown) ; the switches short-circuit part of the field winding or switch a supplementary field winding, Fig. 5 (not shown) ; a resistance in shunt with the field of a series-wound motor is varied, Fig. 6 (not shown) ; part of the secondary of a transformer supplying the armature of a compensated repulsion motor is switched in and out of circuit, Fig. 7 (not shown) ; polarized conducting semicircular rings are used in place of the segments 18, 29, Fig. 8 (not shown).