Simplified sensorless DC motor commutation control circuit using analog timing techniques

摘要: Initial start-up of a polyphase, brushless DC motor (used for hard disk drive system) is accomplished by sequentially applying current to each the phases motor. When back EMF zero-crossing detected in one motor, after an appropriate delay allow next phase come into position, applied that phase. Thus, position rotor determined from which power currently being supplied. A proportional speed used between detection and powering sequence. brought up its operating 3600 or 5400 rpm's successive stages with (1) initial relatively slow energization stator coils (2) long masking spurious signals, (3) shorter times, (4) maintaining rotational disks at using any various methods commonly known employed those ordinary skill.