Due to the fact that brushless motors deliver an optimized torque per package size, they are used widely in various applications.  Because of this, they are both  smaller in size and lighter in weight, subsequently  providing a higher peak overload capacity with wider speed range capability, as well as providing a long, reliable and maintenance-free life.  If time-up-to-speed is an important consideration for your applications, brushless motors is much faster.  Other advantages can also be gained when powering a brushless motor with an AC drive scheme.

Basic Motor Operation

Motor rotation is based on the fact that if a conductor carrying current is placed in a magnetic field, a force will act upon it.  One of the simplest motors in use today is the AC motor.  It consists of windings on a peripheral housing, (stator assembly) and an internal assembly (rotor).  The motor suddenly operates when power is applied onto the stator winding assembly, thus resulting in current flow that sets up the first magnetic field.  This in turn induces current in the rotor setting up the second field.  It is the interaction between these two magnetic fields which results in rotation.  The AC motor is thus basically a constant speed motor, with speed being dependent upon the frequency of the applied voltage. 

In contrast, the DC motor was designed so as to use permanent magnets on the stator to set up the first magnetic field.  The rotor, which sets up the second field, is made up of several windings and a commutator.  Each winding consists of turns of wire set between steel laminations to concentrate the magnetic field.  When power is applied onto the rotor, current passes through the windings, thus setting up the second field. As the two fields interact, resulting in rotation, they will normally align and rotation ceases.  However, the mechanical commutator switches power from winding to winding, thus maintaining the rotor magnetic field at the optimum angle with respect to the permanent magnet field to obtain maximum torque and efficiency from the motor.

Brushless motors incorporate the most beneficial attributes of each design to provide the best of both – the long life of the AC motor and smaller size of the DC motor.  The design and layout of a brushless motor includes electrical windings on the outside stator housing, similar to the AC motor (however only three windings), and like the DC motor the brushless design also includes permanent magnets mounted on the rotor.

Types of DC Drives offered by EP Normand

 

The following types of DC Drives are offered by EP Normand:

• DC590P;
• DC512C;
• DC514C; and
• DC506/7/8.