The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 28, 1991
Filed:
Mar. 27, 1990
Marcos G Schwarz, Joinville, BR;
Empresa Brasileira De Compressores S.A., Joinville SC, BR;
Abstract
A method and electronic circuit for controlling a brushless direct current motor, the motor having stator coils and a rotor with permanent magnets, in which the rotor position is detected by induced voltages. A control circuit has an inverter for supplying current (I.sub.1, I.sub.2, I.sub.3) to the stator coils (1, 2, 3); a circuit detecting the relative position of the rotor-stator from the induced voltages; and a control circuit processing information (I.sub.m) of current being supplied by the inverter to the stator coils, reference speed (W.sub.ref) and on rotor position (P.sub.1, P.sub.2, PP.sub.3) by sending control signals (S1 to S6) to the inverter. The control circuit comprises a main logic circuit or digital memory, delay elements connected in series, a circuit controlling the supply of current to the motor, a circuit detecting the minimum speed limit of the motor, a circuit for converting the frequency/voltage, a voltage comparator circuit and a Proportional-Integral-Derivative circuit.