| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving device for a sensorless brushless motor having a function of determining abnormal behavior of rotational position detection while enhancing the reliability for the rotational position detection and suppressing an increase in cost.SOLUTION: The driving device for the sensorless brushless motor 1 includes an inverter circuit 2 for energizing a motor terminal in a duty-on time zone of a pulse width modulation signal, an inverter control circuit 3 for generating the pulse width modulation signal and instructing the inverter circuit 2, a position detection circuit 4 for detecting an induction voltage induced on the terminal and detecting the rotational position of a rotor, and an energization timing circuit 5 for setting switching timing of an energization phase on the basis of the position detection timing, further includes a counter electromotive voltage detection circuit 6 for detecting a counter electromotive voltage generated at the terminal immediately after the switching timing, and an abnormal behavior determination unit 7 for determining the presence of abnormal conditions of the rotational position detection by comparing the time zone in which the counter electromotive voltage detection circuit 6 detects the counter electromotive voltage and the position detection timing of the position detection circuit 4. |
