18-10-2010, 12:25 PM
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INTRODUCTION
Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are used in industries such as Appliances, Automotive, Aerospace, Consumer, Medical, Industrial Automation Equipment and Instrumentation. As the name implies, BLDC motors do not use brushes for commutation; instead, they are electronically commutated.
BLDC motors have many advantages over
brushed DC motors and induction motors. A few of
these are:
• Better speed versus torque characteristics
• High dynamic response
• High efficiency
• Long operating life
• Noiseless operation
• Higher speed ranges
In addition, the ratio of torque delivered to the size of the motor is higher, making it useful in applications where space and weight are critical factors. In this application note, we will discuss in detail the construction, working principle, ch aracteristics and typical
CONSTRUCTION AND OPERATING
PRINCIPLE
BLDC motors are a type of synchronous motor. This means the magnetic field generated by the stator and the magnetic field generated by the rotor rotate at the same frequency. BLDC motors do not
experience the “slip” that is normally seen in induction motors. BLDC motors come in single-phase, 2-phase and 3-phase configurations. Corresponding to its type, the stator has the same number of windings. Out of these,
3-phase motors are the most popular and widely used .This application note focuses on 3-phase motors. are often available in public places such as railway and service stations .In the office you can connect mobile devices to the network using cables or wireless technology. Wireless-enabled devices - laptops, PDAs etc - can automatically connect to their 'home' network when in signal range in order to synchronise data with office databases and file servers so that data on all devices is up to date.