Voice Coils

Cobham Advanced Electronic Solutions can tailor a motor for your specific application. This customization can include size variations and winding characteristics to accommodate power supply availability, performance parameters and physical mounting requirements.

The voice coil is an electromagnetic actuator in its simplest form.  Voice coil actuators come in two forms; rotary and linear.  A linear voice coil will move in a back and forth motion and the rotary voice coil moves in an arc.

Voice coil actuators are ideal when a inertial mass needs to be accelerated quickly or positioned accurately.  The control circuit to drive a voice coil is not complicated as a voice coil does not require commutation.

A voice coil is a two-element device.  There will be a coil assembly and a permanent magnet assembly.  The coil assembly is inserted into the permanent magnet field.  When current passes through the coil a magnetic flux field a force is produced at a right angle to the direction of the current.  This produces the back and forth motion of a voice coil.


Application Considerations

Some important characteristics/features of voice coils are as follows:

  • Due to the simple construction and electrical interface, voice coil actuators are generally a low cost alternative to other types of brushless motors
  • Limited motion or stroke
  • Can be positioned with a high degree of accuracy
  • Capable of high accelerations
  • Low friction and hysteresis
  • Voice coils offer cogless operation

Custom Voice Coil Applications

When you contact Cobham Advanced Electronic Solutions about your voice coil application please be prepared to discuss the following requirements:

  • Maximum Force
  • Stroke
  • Acceleration
  • Duty Cycle

Other parameters of interest to the motor designer are:

  • Available envelope
  • Controller constraints (current, interfaces etc.)
  • Description of the mass to be moved
  • Temperature range
  • Other special environmental requirements (vibration, vacuum, etc.)
Motion Control and Positioning