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:
Mar. 30, 1999
Filed:
Jan. 18, 1996
Marquardt GmbH, Rietheim-Weilheim, DE;
Abstract
The invention relates to a method for driving an electric motor (1) which is employed, in particular, in manually guided electric tools, such as drilling machines, screwing machines or the like. Variable pulses of an electric voltage are applied to the electric motor (1) in such a way that the rotor of the electric motor (1) moves at a rotational speed which can be set. In order that the rotor of the electric motor (1) moves intermittently or abruptly, at least parts of at least individual pulses are blanked by superposition of a pulse interval having a zero voltage. A circuit arrangement for a method of this type has control electronics (5) and an electronic power switch (4), such as a triac, a transistor, an IGBT or the like, which is switched by the control electronics (5) in such a way that the variable pulses can be applied to the electric motor (1) via the electronic power switch (4). The control electronics (5) further contain means for switching the electronic power switch (4) off during at least parts of at least individual pulses.