What is a Voice Coil Actuator?

A voice coil actuator, also known as a non-commutated DC linear actuator, is a type of direct drive linear motor. The name “voice coil” comes from one of its historically first applications: vibrating the paper cone of a loudspeaker. They are currently used for a wide range of applications, including moving much larger masses. It consists of a permanent magnetic field assembly (permanent magnets and ferrous steel) and a coil assembly. The current flowing through the coil assembly interacts with the permanent magnetic field and generates a force vector perpendicular to the direction of the current. The force vector can be reversed by changing the polarity of current flowing through the coil.

A non-commutated DC linear actuator, typically referred to as a voice coil, is capable of a displacement of up to 5 in., whereas most actuators have displacements up to 2 in. Voice coils come in a range of sizes, from devices that generate a few ounces of force, to others that generate several hundred pounds of force. In addition, voice coil actuators can move bi-directionally, have a constant force over the stroke, and can be used for either...