ELECTRODYNAMIC BRAKING DEVICE FOR A UNIVERSAL MOTOR
First Claim
1. An electrodynamic braking device for a universal motor having a field winding (2, 2′
- ) and an armature (1), having a switching device (S1-S6, S8, 3, v, v′
, v″
) for switching from a motor mode to a braking mode, wherein the braking device is designed to supply the armature (1) and the field winding (2, 2′
) with an alternating current of a power grid (50, 51) during the motor mode,wherein said braking device is designed to short circuit said armature (1) and to continue to supply said field winding (2, 2′
) with an alternating current from the power grid (50, 51) during the braking mode,wherein said braking device is designed to supply said field winding (2, 2′
) with a current having an A.C. voltage which has the frequency of said power grid in a first phase, of said braking mode andwherein said braking device is designed to supply the field winding (2, 2′
) with an alternating current from said power grid which has a frequency that is reduced with respect to the frequency of said power grid in a further phase of the braking mode.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to an electrodynamic braking device and to a method for braking a universal motor having a field winding and an armature. The universal motor can be switched from a motor mode to a braking mode. In the motor mode, the armature and the field winding are supplied with an alternating current of a power grid. In the braking mode, the armature is short-circuited and the field winding continues to be supplied with an alternating current from the power grid. In a first phase of the braking mode, the field winding can be supplied with an alternating current having the frequency of the power grid. In a further phase of the braking mode, the field winding is supplied by the power grid with an alternating current having a frequency that is reduced with respect to the frequency of the power grid.
23 Citations
24 Claims
-
1. An electrodynamic braking device for a universal motor having a field winding (2, 2′
- ) and an armature (1), having a switching device (S1-S6, S8, 3, v, v′
, v″
) for switching from a motor mode to a braking mode, wherein the braking device is designed to supply the armature (1) and the field winding (2, 2′
) with an alternating current of a power grid (50, 51) during the motor mode,wherein said braking device is designed to short circuit said armature (1) and to continue to supply said field winding (2, 2′
) with an alternating current from the power grid (50, 51) during the braking mode,wherein said braking device is designed to supply said field winding (2, 2′
) with a current having an A.C. voltage which has the frequency of said power grid in a first phase, of said braking mode andwherein said braking device is designed to supply the field winding (2, 2′
) with an alternating current from said power grid which has a frequency that is reduced with respect to the frequency of said power grid in a further phase of the braking mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- ) and an armature (1), having a switching device (S1-S6, S8, 3, v, v′
-
15. A method for braking a universal motor having a field winding and an armature, wherein the universal motor can be switched from a motor mode to a braking mode,
wherein the armature and the field winding are supplied with an alternating current of a power grid during the motor mode, wherein said armature is short-circuited and said field winding continues to be supplied with an alternating current by the power grid during the braking mode, wherein said field winding is supplied with an alternating current having the frequency of said power grid in an initial phase of the braking mode and wherein said field winding is supplied by said power grid with an alternating current having a frequency that is reduced with respect to the frequency of said power grid after the initial phase of the braking mode in a further phase of said braking mode.
Specification