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:
Apr. 10, 1990
Filed:
Apr. 26, 1989
Timothy M Rowan, Wauwatosa, WI (US);
Robert J DeLange, St. Francis, WI (US);
Allen-Bradley Company, Inc., Milwaukee, WI (US);
Abstract
An electric motor is braked by applying pulses of current to a winding of the motor creating a negative torque which slows the motor. In order to detect when the motor has stopped and as a consequence, when to discontinue applying the current pulses, a periodic determination is performed as to whether the back emf voltage induced in a winding of the motor is within a range of defined values, such as between a positive reference voltage level and a negative reference voltage level. The application of pulses of current is terminated a given interval from when a predetermined number of consecutive determinations all indicate that the back emf voltage is within the range. The length of the given interval is derived from the amount of time between when the electricity began to be applied to brake the motor and the occurrence of the predetermined number of consecutive determinations.