| 摘要 |
PROBLEM TO BE SOLVED: To adopt a method of determining, for detecting rotor positions of a brushless DC motor, by the form of a pulse wave which is generated by comparing a three-phase induced voltage and the reference voltage of an inverter, and to surely detect rotor positions, using a low-cost configuration, even if the waveform (on) of one phase generated, in the case of induced voltage being generated from two phases, has a narrow waveform (on-width) in comparison with the waveform (on) of the other phase. SOLUTION: The rotor position detecting patterns obtained from three phases are of 3-bit data, with a preceding pattern and a regular pattern occurring within one current-carrying section, and if the preceding pattern is 2-bit on, an interrupt is caused to occur having a 2-bit on pattern, and after the interrupt is verified, a shift is made to wait for a regular pattern of 1-bit on; when a rotor-position detecting interrupt with a regular pattern occurs, a decision is made that the detection of rotor position within one current-carrying section has been completed, thus resulting in an accurate control of rotor position detection. |
