Electromagnetic brakes (also called electro-mechanical brakes or EM brakes) slow or stop motion using electromagnetic force to apply mechanical resistance (friction). The original name was “electro-mechanical brakes” but over the years the name changed to “electromagnetic brakes”, referring to their actuation method. Since becoming popular in the mid-20th century especially in trains and trolleys, the variety of applications and brake designs has increased dramatically, but the basic operation remains the same.
Both electromagnetic brakes and eddy current brakes use electromagnetic force but electromagnetic brakes ultimately depend on friction and eddy current brakes use magnetic force directly.
In locomotives, a mechanical linkage transmits torque to an electromagnetic braking component.
Trams and trains use electromagnetic track brakes where the braking element is pressed by magnetic force to the rail. They are distinguished from mechanical track brakes, where the braking element is mechanically pressed on the rail.
Electric motors in industrial and robotic applications also employ electromagnetic brakes.
Recent design innovations have led to the application of electromagnetic brakes to aircraft applications. In this application, a combination motor/generator is used first as a motor to spin the tires up to speed prior to touchdown, thus reducing wear on the tires, and then as a generator to provide regenerative braking
