3-PHASE BRUSHLESS DC MOTOR USING A SINGLE SENSOR
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2001-Nov-07
In a 3-phase brushless DC motor three sensors are required to determine the rotor position and the infor- mation from each sensor specifies the commutation of each winding. The two major problems in a 3-sensor system are cost and mechanical orientation/mounting of these sensors with respect to the stator windings. Fig. (1) shows a single sensor system with a 4.pole rotor and 3 phase windings. The SZ and SI sensors which are normally inside the motor are not used in the present system, but the SI and SS information is generated electronically using the S signal as shown in Fig. (2).