How does the magnetic brake stop the rotation of an electric motor armature?

The mechanism of a magnetic brake in stopping the rotation of an electric motor armature typically involves the relationship between electromagnetic force and mechanical action. In the correct answer, a friction brake is applied by a spring and released by a magnet.

When the electric motor is in operation, the magnetic brake remains released, allowing the armature to rotate freely. When it's necessary to stop the motor, current is directed to the electromagnet, which then activates and pulls back against the spring. This action releases the mechanical tension that keeps the brake engaged and allows the friction brake system to engage. The friction created by this engagement effectively slows and ultimately stops the armature from rotating.

This approach allows for a quick and effective stop, leveraging both the electromagnetic properties and mechanical springs in the brake system. Understanding this can also highlight the role of magnets in controlling mechanical systems, specifically in how they can either engage or disengage mechanical components based on current flow.