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 actuator lend this to applications requiring precise control of force and / or position such as control valves, or lens and mirror positioning systems. One big advantage e.g. over porportional solenoids is the extremely small hysteresis which make Voice Coil Actuators ideally suited for applications requiring well controllable bi-directional movement.