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. 27, 1990
Filed:
May. 21, 1987
Pradeep M Bhagwat, Baltimore, MD (US);
Richard T Walter, Baltimore, MD (US);
Alan A Gilmore, Baltimore, MD (US);
Black & Decker Inc., Newark, DE (US);
Abstract
A pulsating D.C. voltage is developed by a rectifier 86 and is filtered by a capacitor 100 to facilitate application of a relatively smooth, enhanced D.C. voltage to a motor 106. The charged voltage of capacitor 100 is applied across a series circuit which includes a rheostat 118, a resistor 126 and motor 106. When the CEMF of motor 106 drops as a result of a decrease in motor speed, a disc 122 is biased through the voltage appearing across rheostat 118 and resistor 126 to cause an SCR 116 to fire. When SCR 116 fires, the voltage of capacitor 100 supplies a boost of power to motor 106 to overcome the decrease in motor speed. A circuit 212 prevents an overspeed of motor 106 from occurring while braking circuits 264, 266 and 268 provide for a dynamic braking effect when the motor is a universal motor.