Does active braking hold a load in the air, can it replace a mechanical brake?
No. Electrical braking produces counter-torque only while there is motion; when the motor stops the back-EMF is zero and no holding torque remains. Moreover, when the supply is cut the protection disappears entirely. In every application where the load hangs in the air, a mechanical brake or a self-locking transmission is mandatory.
The physical limit of electrical braking is this: the counter-torque arises from the back-EMF generated by the motor turning. When the motor stops, the back-EMF falls to zero and the braking torque goes to zero as well. If the load starts sliding down under gravity, the motor starts turning again and only then does some resistance form; that is not controlled holding but a sliding descent.
The second limit is dependence on energy. In case of a blown fuse, a broken cable, a battery isolator opening or a driver failure, the electrical brake is completely out of action. A safety function must be designed so that it engages by itself when the energy is cut; spring-applied, electrically released mechanical brakes work on this principle.
The correct arrangement for lifting and platform applications:
- The load is held by a mechanical brake or a self-locking (worm gear, screw actuator) transmission.
- The driver's current-threshold stop function (AntiSwitch on the KS250 and PT500) is for end of travel and overload, not for holding.
- The electrical brake is used only to shorten the stopping distance.
Electrical braking must never be relied on for any load a person could be underneath.
Full topic: DC Motor Driver Selection Guide