Motors, Generators, Actuators & VCMs

A motor is any device that turns electrical energy into mechanical energy.  A generator turns mechanical energy into electrical energy.   Motors are used in applications ranging from building elevators, to kitchen appliances, to your friendly dentist's drill.

Force on the conducting coils on the rotor is the result of magnetic field interactions.  Force on one coil is in the downward direction and force on an another conducting coil is in the upward direction. This causes the coil to rotate about the axis. When the coil is just past the vertical position, electrical current is reversed.  This causes torque on the rotor to always be in the same direction and the motor continues to spin. 

In a generator, spinning the armature causes the current loops to pass through the static magnetic field and electrical energy is generated.  The most common generator application is in automobiles.  These convert a part of the gasoline/diesel engine's rotational energy into electric power.

All motors and generators contain a stator and a rotor. The permanent magnet is located on either the stator or the rotor with the coil on the other component.  Until the advent of rare earth permanent magnet materials, the magnet was typically located on the stator, to maximize the magnetic field in the gap.  Since the coil was located on the rotor and was in motion, brushes had to be used to carry the electricity out from the coils.  The brushes wore out after a time and required replacement.  Now, with the higher energy rare earth magnet materials, the magnet can be on the rotor and the coil on the stator.  This makes for a more stable winding configuration and brushes are no longer needed to carry the generator output.

A voice coil motor is a particular type of motor that is designed to provide linear motion. However, a voice coil motor is typically not driven by a direct current. Instead, it is driven with an alternating current (AC). We have AC electrical supply fed into our homes. It is a much more efficient method of powering electric devices. Why is a voice coil motor called a voice coil motor? It came about as a way to translate the sound of the human voice into a mechanical vibration. Voice coil motors are used primarily in loudspeakers. However, voice coil motors are used in many different types of actuators.

For further inquiries, please e-mail us at info@dextermag.com -or- call us at:  800-345-4082 (In North America) or +44 (0) 1189 602430 (In Europe).