Spring Applied brakes also known as fail-safe brakes engage when the electrical power is turned off. Spring Applied brakes can be used as a static holding brake or used to decelerate a mass as quickly as possible in low cycle dynamic applications. Spring applied brakes are most commonly mounted on the back side of a motor shaft. These are offered in a variety of stator/magnet voltages.
Numerous designs and options are available, including how the brake is actuated (electric, pneumatic, hydraulic), noise reduced, environmental ratings (IP) for water/moisture intrusion, hand release for manual operation, microswitch for wear or operational monitoring and extreme cold weather versions to name just a few.