Andreas Stihl Ag Co. Kg

Jens Kloeker

Jochen Luz

Johannes Menzel

Harald Mang

Gernot Liebhard

Heinrich Leufen

Kay-Steffen Gurr

Arne Untermann

David Kraetzig

David Hampe

Markus Maier

Christian Renz

Ante Hamersmit

Jochen Siller

Ina Schneider

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.

Method and apparatus for the detection of the position of an operating switch for starting an electric motor

A handheld work apparatus having an electric motor and a drive circuit for the electric motor. The rotation movement of the motor is converted into an oscillating movement of the work tool via a gear mechanism. The motor is situated in a circuit including at least the motor and a switch for operating the motor. To reduce wear of the gear mechanism, a control unit for operating the motor in one of two directions of rotation is provided. The control unit independently determines a selected direction of rotation for a next operating cycle as a function of a control variable. When the motor is started, the motor is started by the control unit in the direction of rotation which is associated with a value of the control variable. The control variable changes before the motor is restarted for a following operating cycle.

Handheld work apparatus having a drive circuit for an electric motor which drives oscillating tools

The invention relates to a portable work apparatus having a housing and a work tool which is driven by an electric motor via a gear assembly. A flywheel which rotates about a rotational axis is arranged in the drive train between the electric motor and the gear assembly, which flywheel is connected fixedly to an output shaft so as to rotate with it, which output shaft protrudes into a gear assembly space and has a drive pinion. The output, shaft and the flywheel are mounted in the housing by two bearing locations, the rotational axis of the flywheel and a motor shaft of the electric motor lying coaxially with respect to one another, and the motor shaft of the electric motor being connected fixedly to the flywheel so as to rotate with it. The electric motor is fixed in the housing exclusively via a torque support.

Portable, electric work apparatus

Growing community of inventors

Waiblingen-Bittenfeld, Germany

Jens Kloeker