What is Moving Coil?

At the heart of all SMAC actuators is the moving coil, also described as a voice coil actuator. The essential principle is the same as you will find in any permanent magnet loudspeaker. The voice coil sits in a strong magnetic field, and by passing a current through the coil a force is generated in either direction. With SMAC actuators, the moving coil makes an ideal linear motor.

The amount of force generated is governed by the equation:

F  N I B

where:
  F is the force generated
  N is the number of turns in the winding (Constant)
  I is the current flowing through the winding and
  B is the magnetic flux (Constant)

Therefore, by controlling current we can accurately control the force output.

Benefits of Moving Coil Technology

• Lower moving mass with the voice coil actuator means extremely high acceleration and velocity, as opposed to the heavier “moving magnet” technology used in most linear motors.
• Safe and energy efficient: operates at low current, typically at 1.5 amps at 24 volt DC.
• Quite (< 55dB), airless operation: no expensive compressed air generation required. No air consumption or air leaks to attend to. No compressed air generating environmental particulate contamination.
• No pressure valves, no force fluctuations caused by air pressure fluctuations.

SMAC Unique Features and Advantages

• Fully programmable in Position, Acceleration, Velocity and Force.
• Direct drive = no backlash, a very high degree of accuracy & repeatability.
• Sub-micron resolution (5µm to 100nm)
• Force control = Soft-Land capability: light force without damaging parts/material being handled.
• >250 million cycles MTBF = long operation life

SMAC Actuators Offer Flexibility:

• Integrated position measuring system with glass scale and optical reader head (no contact wear).
• Ability to switch between operations - force, position and velocity mode - at any time.
• “On the fly” adjustable movement allows quick changeover.
• Constant force monitoring and control.
• Digital and analog input/output channels.
• SMAC linear motors are a servo system, hence can be programmed to decelerate smoothly and quickly. Mechanical slamming can be totally eliminated.
• Competitively priced electric actuators that offer all above features and benefits.

Take a look at this side-by-side comparison of moving coil technology vs pneumatics. 

For more information on SMAC actuators, contact us to request a product demo.