Motor control for box printing equipment

摘要

A motor control system for controlling the operating speed and direction of a three-phase induction motor. The invention particularly finds use for bringing a rotary printing cylinder precisely into register for processing products in sheet form, such as for printing sheets of corrugated cardboard in a machine for printing corrugated boxes. A three phase induction motor is single phase powered by an AC drive through a first and a second electrical conductor. Direction switching signals and time delay speed switching signals are applied to the appropriate terminals of the AC drive by the second and a third electrical conductor. This allows motor powering and control using only three conductors, such from as the slip rings on industry standard corrugated box printing equipment.