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:
Aug. 28, 2018
Filed:
Apr. 14, 2017
Andreas Stihl Ag & Co. KG, Waiblingen, DE;
Kay-Steffen Gurr, Heilbronn, DE;
Gernot Liebhard, Waiblingen, DE;
Jens Kloeker, Erdmannhausen, DE;
Jochen Siller, Ludwigsburg, DE;
Heinrich Leufen, Schwaikheim, DE;
Andreas Stihl AG & Co. KG, Waiblingen, DE;
Abstract
An electric motor is connected to a voltage source via a drive circuit and, between the drive circuit and the voltage source, the operating switch is arranged for the switching of the supply voltage (U) of the voltage source as the input voltage (U) on the drive circuit. Following the switch-out of the electric motor, the input voltage (U) on the drive circuit is monitored and a gradient of a rising voltage ramp (dU/dt) of the input voltage (U) is determined. The gradient of the rising voltage ramp (dU/dt) of the input voltage (U) thus determined is compared with a predefined limiting value and, in the event of an overshoot of the predefined limiting value, the operating switch is detected as closed, and the electric motor is restarted via the drive circuit.