| 摘要 |
"Controlled braking device for electric motors and in particular portable tools" A method of braking a universal electric motor comprising a field winding (12,112,212) and an armature (11,111,211) comprises the steps of short-circuiting the armature (11,111,211), powering for a braking period the field winding (12,112,212) with at least a predetermined braking voltage, completely cutting off power from the motor after the end of the predetermined braking period. An electric motor (10,110,210) comprises means (16,116,216) of powering the motor and means (18,118,215a) of controlled cut-off of the power supply. Upon operation of means of short-circuiting of the motor armature the power supplies means supply the field windings (12,112,212) with at least one predetermined braking voltage. Upon exhaustion of a braking period, the cut-off means operates to cut off power completely from the motor.
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