| 摘要 |
PROBLEM TO BE SOLVED: To reduce noise and switching loss, by adjusting the switching timing for the input timing of sensor signal from a rotor detection position of a continuous current application pattern, thereby controlling the rotation of a brushless motor. SOLUTION: When a sensor signal from a rotor position detection sensor 2-1 falls from 'H' to 'L' at t1 point, only ΔT is delayed without immediately turning on a transistor Q2. Thereafter, the transistor Q2 is turned on, but no PWM control is performed for the transistor Q2. That is, the switching timing of current application pattern (1) is delayed by ΔT, and the current application pattern (1) is made to a continuous current application pattern. Other current application patterns (2) to (6) are made the same as the current application pattern (1). And this delay time ΔT is adjusted based on the difference between an actual motor rotation speed TR and a motor speed indication value NT. |
