Braking device for an electric motor, electrical apparatus provided with the braking device, and a method of braking
AssigneeRobert Bosch GmbH
InventorsDietmar Hahn, Roland Walter
Life of this patent
Estimating the term…
Abstract
A braking device for an electric motor of a power tool has a short circuit switch for short circuiting an armature winding of the electric motor during a braking process, the short circuit switch for controlling its switch condition having a control input, a control unit connected with the control input of the short circuit switch for performing a phase control of the short circuit switching during the braking process in order to avoid brush fire; also an electrical device with such a braking device and a braking method are proposed as well.
Claims7
A braking device for an electric motor of a power tool, comprising a short circuit switch for short circuiting an armature winding of the electric motor during a braking process, said short circuit switch having a control input for controlling a switching condition of said short circuit switch;
- a control unit connected with said control input of said short circuit switch for performing a phase control of said short circuit switch during the braking process in order to avoid brush fire, and further comprising means for supplying current to a field winding of said electric motor during braking of the electric motor at least over a certain time while the armature winding is short circuited.
Dependencies are inferred from the claim text.