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:
Nov. 16, 1993
Filed:
Apr. 28, 1992
Applicant:
Inventors:
Fritz Schmider, Hornberg, DE;
Thomas Von Der Heydt, St. Georgen, DE;
Assignee:
Papst Licensing GmbH, Spaichingen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02K / ;
U.S. Cl.
CPC ...
318138 ; 318254 ; 318463 ;
Abstract
A low noise brushless dc motor has a rotor with a permanent magnet and a stator with a bearing system mounting a shaft for rotating the rotor. The motor has an operating circuit that includes a tachometer winding connected to the base of a first transistor whose collector is in series with a first resistor. The other end of the tachometer winding is connected to the base of a second transistor whose collector is in series with a second resistor.