This paper presents four excitation techniques for Permanent Magnet Brushless DC motor 'drive.
These techniques are single phase excitation technique, two phase excitation technique, three
phase excitation technique and single phase I two phase excitation technique. Waveforms of phase
current and torque for all excitation techniques are analyzed and discussed. The operation of the
motor drive at different excitation techniques for same load is studied and discussed. The results
of this studying reports an investigation into the characteristics of such techniques according to
torque, no load speed, efficiency, supply current and control circuit. Computer simulation result
had shown a noticeable difference between four excitation techniques