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:
Feb. 19, 1985
Filed:
Jun. 09, 1983
Ricky F Bitting, Raleigh, NC (US);
William Peil, North Syracuse, NY (US);
General Electric Company, Fort Wayne, IN (US);
Abstract
In a motor speed or torque control circuit for an electronically commutated motor (ECM) used in a ceiling fan, a pulse width modulator operating at an above audible pulse repetition rate is used in combination with means to adjust the motor voltage to achieve a large (20 to 1) range of smooth fan speed adjustment. The pulse width modulator, which takes the form of a comparator, has as inputs an invariant sawtooth voltage waveform, and a smooth, adjustable control voltage dependent on the voltage supplied to the motor. A steady state or pulsed output is produced dependent on whether intersections occur at the comparator input. The active output state of the pulse width modulator is used to control the application of power to the motor. The control circuit permits speed or torque control from a wall location, or on the ceiling fixture combining the motor. The speed or torque control circuitry is designed for use in a maximally integrated ECM control circuit. The invention also concerns a method of controlling the torque or speed of an ECM.