Speed tracking circuit for multi-motor drive - has amplifier with controlled limiting characteristic in each motor control circuit with feedback to all speed control amplifiers

摘要

Each motor has a tachometer speed feedback and a common speed reference connected to a speed regulating amplifier (3). Between this amplifier and a current regulator (5) is an additional amplifier (81) with a controlled (82) limiting characteristic corresponding to armature current limiting. The difference between the input and output of each of these amplifiers is applied to an amplifier (76) providing a common feedback path for all the regulating amplifiers. This feedback signal modifies the speed reference for all the machines. When the limiting feedback responds the input to all motors is restricted until the excessive individual input vanishes. The circuit allows the omission of separate overload protection and its coordination with the control.