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:
Sep. 18, 1990
Filed:
Aug. 28, 1989
Joseph R Pottebaum, Brookfield, WI (US);
A. O. Smith Corporation, Milwaukee, WI (US);
Abstract
A speed control circuit (50) for a single phase AC induction motor (12) includes a phase control circuit (10) for connecting a main winding (16) to an AC source (18) at a variable time delay phase angle during the half cycle of the AC source, and a boost circuit (52) including a motor speed sensor (54, 56) sensing motor speed and altering the delay interval phase angle in response thereto. The boost circuit shortens the delay interval in response to decreasing motor speed, and lengthens the delay interval in response to increasing motor speed, such that almost full voltage is applied during starting of the motor, which voltage is reduced as the motor begins running.