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. 23, 1981
Filed:
Dec. 21, 1979
Michael J Burke, Rochester, MN (US);
David W Collins, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A brushless D. C. motor is disclosed having two bifilar winding wire pairs with each bifilar pair forming alternate windings. Each winding is switched by a transistor which has a back poled diode connected in parallel therewith. The control circuit sequences energization of single windings with each winding energized being in a different bifilar pair than the next preceding energized winding whereby when a transistor is switched off the other winding of the bifilar pair and the associated back poled diode protect the transistor and provide an energy conserving/heat eliminating path for the induced current. Each winding is further formed of a pair of subwindings having an angle of separation therebetween approximately half the angular separation between adjacent windings.