Abstract: An electric motor with an electrodynamic braking means, where the same power controller is used in both motor operation and in braking. Therefore, the field current with the separately excited electric motor can be controlled or regulated by the power controller. It is also possible to preset a certain braking time. A measure of the braking current is obtained by sensing the voltage at a braking resistor, so the braking current can also be regulated on the basis of the field current.

Abstract: In known electrically operated handheld machine tools, a potentiometer serving to control output must be balanced so that a desired tap resistance can be tapped at the potentiometer in a determined adjustment position of the potentiometer. To reduce manufacturing expenses, this balancing is effected without required additional structural component parts or costly additional devices.The potentiometer (20) has a resistance path (21) with which a slider (22) is in electrically conducting contact by pressing. The slider (22) can be actuated manually by an actuating member (15). The slider (22) and actuating member (15) have means (26) for adjusting their relative position with respect to one another after their insertion into a housing (11) of the handheld machine tool.

Abstract: A series motor has a braking device, a stator having a field winding and a pole shoe plate pack, the pole shoe plate pack of the stator having field coils and also having a further element inducing a magnetic field, a rotatable armature, and an element for influencing a braking operation of the field winding.