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:
Sep. 23, 2008
Filed:
Oct. 13, 2006
Applicants:
Christof Kress, Deizisau, DE;
Martin Beichter, Stuttgart, DE;
Inventors:
Christof Kress, Deizisau, DE;
Martin Beichter, Stuttgart, DE;
Assignee:
C. & E. Fein GmbH, , DE;
Primary Examiner:
Int. Cl.
CPC ...
H02P 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A circuit for a series motor for a power tool is disclosed, wherein reliable switching is achieved by means of two electronic switches, without the use of a mechanically disconnecting switch. To this end, two electronic switches, preferably triacs, are preferably connected in series to each other, the voltage drop across the triacs being continuously monitored by a monitoring circuit. A check for faults can be carried out before switching on the power tool. Alternatively, a fusible cutout can be tripped by means of a protective switch connected in parallel thereto.