Sewing machine motor brake - has number of braking actions to bring it to rest at pre-set position

摘要

An operational amplifier controls the monoflops, in series, through a phase lead control. This provides alternate braking of the sewing machine motor and motor running according to a number of pre-set positions. A position indicator provides the positioning information to the reset input for the monoflops. Designed to stop the sewing machine motor so that the needle is in any given position, the system uses a conventional two-phase AC motor suitable for a domestic current supply eliminating the need for a three-phase or DC motor to give the same result, in a small, light unit.