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:
Jul. 13, 1999
Filed:
Aug. 15, 1997
Jeffrey A Reichard, West Allis, WI (US);
Michael Lemcke, South Milwaukee, WI (US);
Ali I Uzumcu, Hoffman Estates, IL (US);
S-B Power Tool Company, Chicago, IL (US);
Abstract
A controller controls the running speed of a variable speed motor of the type which runs at a speed related to the duty cycle of a pulse width modulated drive voltage applied to it and to the load being applied. The controller includes a setting switch for setting the motor running speed and a device for measuring the load being applied to the motor. Also included is a data storage for storing data representing a plurality of different pulse width modulation duty cycles for driving the motor at various desired motor running speeds and with various loads being applied to the motor. A processor is operatively connected to the setting switch, the load measuring device and the data storage for generating signals representing a particular duty cycle corresponding to a desired running speed setting and applied load to result in the desired motor speed. The processor generates these signals at a predetermined time interval to reach and maintain the desired motor speed. A voltage applying device is provided for applying the pulse width modulated voltage having the particular duty cycle to the motor.