Which type of motor is used for precise and repeatable positioning of valves or dampers?

The stepper motor is specifically designed for applications where precise and repeatable positioning is crucial, such as in controlling valves or dampers. This type of motor works by moving in discrete steps, allowing for accurate control over its position without the need for additional feedback mechanisms. Each step corresponds to a fixed angle of rotation, which ensures that the motor can return to the exact same position reliably after each cycle.

In control systems, particularly in automated processes requiring fine adjustments, stepper motors allow for incremental movement that can be precisely calculated. This capability is essential in applications where the exact positioning of mechanical components, like valves and dampers, is necessary for system efficiency and operation, ensuring fluid flow control meets operational demands.

Other options do not provide the same level of precision and repeatability. For instance, modulating motors can offer some level of control but may not achieve the same precision as stepper motors. A Wheatstone bridge is not a motor but a circuit used for measuring electrical resistance and doesn't apply to the positioning of mechanical components. Solenoids, while effective for on/off applications, don't provide the nuanced control needed for precise positioning; they simply engage or disengage a mechanical link rather than allow for incremental adjustments.