| 摘要 |
PROBLEM TO BE SOLVED: To perform the rotation of a sensorless brushless DC motor without delay in control time and accurately. SOLUTION: The revolution control is performed without a rotor's position sensor, by detecting the zero cross of counter electromotive force generated in drive coils W1-W3 from a rotor R (L1 sens, L2 sens, and L3 sens) so as to forecast the position of the rotor R, generating the motor drive voltage pulses (L1+, L1-, L2+, L2-, L3+, and L3-) synchronized with it by one-chip microcomputer 5, and giving them to the motor coils W2-W3. The velocity detection capacity at low velocity can be raised by using the zero cross as motor driving pulses from the zero cross of the counter electromotive force of all three phases generated by the rotation of the rotor by counters 51 -53 . |
