Redundant braking system with constant braking torque and printing press having the braking system

An electric braking device for machines, the braking device comprising:

• a power converter;
• at least one electric drive motor to be braked, said at least one electric drive motor being supplied by said power converter in motor operation and braked by said power converter in generator operation;
• and
• a redundant electric braking device having at least two braking stages and a circuit including a first switch, a second switch being actuated in at least two stages, at least one brake resistor, a comparator receiving a measured actual braking current and comparing the measured actual braking current to a desired braking current, and a control unit using said first switch for switching on said redundant electric braking device upon a failure of said power converter;
• said second switch being controlled to maintain a braking torque on an approximately constant level given a rotational speed of said electric drive motor.