Method and apparatus for controlling and regulating a motor with a permanent magnetic rotor

US4449086A · kind A · utility

Assignee

• The Braun Corporation · DE

Inventors

• Harald Hoffmann · Much, DE
• Dan-Corneliu Raducanu · Bad Soden, DE

Key dates

• Filing date: Dec 8, 1980
• Grant date: May 15, 1984
• Expiry date: Dec 8, 2000

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02P8/04
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A control circuit for driving an electric motor at a substantially constant speed, the motor including a rotor with at least one pair of permanent magnetic poles and a stator provided with a first and second coil, the control circuit including a control element for supplying energizing pulses to the coils dependent upon a detected rotor speed, the control element having a normal speed mode wherein the rotor speed is detected by the first coil and wherein only the second coil is supplied with energizing pulses at a frequency corresponding to single coil driving and a self-starting mode wherein the energizing pulses are supplied alternately to the first and second coils to accelerate the rotor to a desired speed, the control element including rotor acceleration and braking circuitry operable during the normal speed mode and including a desired frequency pulse generator, an actual frequency pulse generator, a phase comparator for comparing the widths and phases of the desired and actual frequency pulses, and an accelerating and braking pulse generator for generating pulses which exert an accelerating force on the rotor whenever the phase of the actual frequency pulses leads the phase …