An overview on state-of-art and future application fields of BLDC motors : design and characterization of a PC-interfaced driving and motion control system

New generations of equipments must have better performances respect to the previous generations, such as higher efficiency, low power consumption, reduced electromagnetic interference, small dimensions, lightness and so on; all these improvements must be achieved while maintaining, at the same time, systems cost as low as possible. Brush-Less Direct Current (BLDC) motors, employed even more in the last years in many equipments in various application fields, present low maintenance costs, compact size, high reliability, efficiency, low power consumption and other optimum features, proposing themselves as excellent candidates for satisfying the stringent requirements mentioned previously. In this paper, after a detailed overview on the current and possible future application fields of BLDC motors, from home appliances, to automotive, industrial automation, medical equipments and robotic instrumentation, the design and realization of a driving and control system of a BLDC motor, with Hall sensors embedded, is presented. A BLDC motor is provided by permanent magnets on moving part (rotor) and windings on fixed part (stator); energized stator windings create electromagnetic poles and the rotor (equivalent to a bar magnet) is attracted by the energized stator phase. By using appropriate sequence to supply stator phases, a rotating field on stator is created and maintained. The lead between rotor and rotating field must be controlled to produce torque and this synchronization implies accurate knowledge of rotor position which is obtained by means of the embedded Hall effect sensors. The realized driving system is composed by three principal blocks: the control electronic board, the power driving board and the BLDC motor. By PC connected via USB with the driving board, the user can choose the motor rotation direction, set the desired rpm value and, by varying potentiometer value located on board, change the rotation speed. Different tests were performed for verifying the correct motor operation and the results show that all the employed devices, driving board, control board and BLDC motor, work properly