VM SERIES: VOICE COIL MOTORS

The VM series of Voice Coil Motors are designed as actuator components. The standard versions of these voice coil actuators are linear actuators and in the most applications the coil is the moving part; the VM series offers incorporate  shafts and sliding bearing as standard to ensure accurate guidance of the coil assembly within the magnet assembly; position sensors are not included. Optionally the Voice Coil Actuators can be shipped without shaft and bearing and also completely customised versions in other sizes and even form factors are available (e.g. like short stroke U-shape ironless motors or rotary versions).

The VM series of Voice Coils Motors addresses applications where excellent control characteristics for short stroke bidirectional linear actuation is required, e.g. in medical or optical equipment. Voice Coil Actuators can develop force in either direction by reversing polarity of excitation. Very important is the very low hysteresis, which is typically two orders of magnitude less than in proportional solenoids. This and the flat force characteristic exhibited by voice coil actuators lend them to applications requiring precise control of force and / or position such as control valves, or lens and mirror positioning systems.

As other motors also Voice Coil Motors develop a voltage while moving (Back-EMF), which is proportional to the relative velocity of the coil in the magnet assembly, so that at constant load and energisation a stationary speed would be achieved, if the stroke would be long enough (like in a DC brushed motor). Because the coil resistance changes with temperature constant force output can only be achieved by current control.