Linear magnetic actuators are all based on the same principle, provide motion thanks to a magnetic force acting at distance.
However one can divide them into two categories.
Moving coil actuator
the design of moving coil actuators is the same as for loudspeakers therefore this kind of permanent magnet actuators are also called voice-coils actuators. The principle is today well known, a mobile coil driven by a current is subitted to a magnetic force generated by a static permanent magnet. As the current switches from positive to negative, the coil gets closer or away from the permanent magnet. These actuators are easily controllable as the strength moving the coil is directly proportional to the applied current.
Moving magnet actuator
The moving magnet actuator is using the opposite design. A moving magnetic assembly is placed inside a stationary coil. Having a stationary coil allows for a simpler design of the electrical connections. The force of a moving magnet actuator is higher than the one of voice-coil actuators, however they are not so controllable. They are today commonly used for locking applications.
In both cases, the magnets used have the same shape: block magnets. They need to be as thin as possible while providing the highest flux density. Therefore they commonly come in one of the best magnetic material today: Neodymium (NdFeB)
Please contact us for any enquiries regarding NdFeB block magnets.