ES355227A1 - An arrangement for controlling the relative synchronism of direct current motors - Google Patents

Abstract

In a system for running several motors of a production line at different but related speeds, each motor is provided with a retroactive speed control system of the kind in which pulses with a frequency dependent on the speed of the motor are compared with reference pulses in a difference counter, the several trains of reference pulses being derived from synchronized sources. In a stretch-winding machine where a thread is fed from a supply roller 14 through stretching stages 15, 16 to a take-up roller 17, each stage of the machine is driven by a motor 1, 2, 3 4, each driving a pulse generator 10, 11, 12, 13. The output of each pulse generator is fed to a counter 18, 19, 20, 21 which also receives references pulses 22, 23, 24, 25 and provides an output controlling a regulator 5, 6, 7, 8, which may comprise a magnetic amplifier-rectifier system or an S.C.R. supplying D.C. to the motors from an A.C. source 9. A multitrack tape recorder 26 provides the several pulse trains. Each motor may drive the corresponding stages of several parallel machines or alternatively (Fig. 2, not shown), one stage of each machine may employ individual motors or (Fig. 3, not shown) separate motors may be used for groups of machines. The tape may have less channels than there are stages, the pulse trains for the extra stages being derived by division (Fig. 4, not shown). An extra channel may provide stopping and starting signals &c. The reference pulses may be derived from tapes, discs, cylinders or matrices which are scanned electrically, mechanically or optically.