Essentially, a constant torque spring functions similarly to a constant force spring. It is typically mounted on a 'storage spool', with its outer end connected in reverse to an 'output spool'. When the output spool is rotated, the spring is wound in the opposite direction, generating a constant torque on the output spool. When the external force is removed, the spring rewinds from the output spool back onto the storage spool, returning to its natural state. This type of spring is suitable for multi-turn applications requiring constant force, such as automatic cable retraction, counterbalancing weights, and power sources.