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:
Jun. 14, 1988
Filed:
Apr. 24, 1987
Applicant:
Inventors:
Richard S Davis, Palo Alto, CA (US);
Allen F Podell, Palo Alto, CA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
310 93 ; 318381 ;
Abstract
A dynamic braking circuit for a universal motor is disclosed. A switching mechanism is used to reverse the orientation of the series field winding with respect to the rotor when power is removed. Because the rotor acts as a generator when power is removed, it will generate current to the field winding. Because the orientation of the field winding has been reversed, the field winding will thus try to make the motor run in the opposite direction, thereby exerting a braking force on the motor. The amount of the braking force is limited by using a portion of a second winding to oppose the reversed action of the first winding.