What is a Voice Coil Stage? Voice coil stages are usually direct-drive linear stages (rotary voice coils are also available) driven by an electromagnetic linear motor consisting of a moving coil winding and a fixed magnet (the opposite is also possible). By precisely controlling the electric current in the coil, the magnetic force (Lorenz force) and thus, acceleration, velocity, and position can be varied, very accurately. For precision positioning applications, a feedback sensor – usually a linear encoder – provides the current position information to a closed-loop controller that compares target and actual position and varies the current accordingly to minimize the error. Since voice coil motors have very low mechanical and electrical time constants (low inertia and short rise time), they are well suited for rapid accelerations of light payloads. Unlike 3-phase motors, no commutation is required, both simplifying the mechanical setup and control.
What is a Voice Coil Actuator? VC Actuators are based on the same principle as stages. Actuators are used to push or pull an external object that has its own guiding mechanism. In contrast to actuators, voice coil stages (often called linear slides) usually incorporate a guiding system that is designed to handle lateral loads.
Voice coils stages are used for short travel ranges, typically on the order of 25mm (1 inch) or below. For longer travel ranges, 3-phase linear motor stages are often the better choice, providing higher forces.
Because of their small dimensions, voice coil motors are often integrated in compact stages, actuators, and fast tip/tilt mirror platforms. Learn more on voice-coil motors, linear motors and custom solutions»