| 摘要 |
PROBLEM TO BE SOLVED: To shift from separately-controlled operation to self-controlled operation smoothly, even if the voltage of a power source changes. SOLUTION: A microcomputer 8 outputs a signal 8b and changes pulse width modulation to be applied to signals 8u, 8v, 8w from a pulse 5a to a signal 8a when a brushless motor 1 rotation speed reaches a constant value by separate control. And the duty cycle of the signal 8a is decided so that the impressed voltages of armature windings may be equal to those at the time of acceleration finish. After that, change-over to self-controlled operation is performed at the point of time when the phases between position detection signals 4u, 4v, 4w and signals 8u, 8v, 8w, 8x, 8y, 8z become a specified value or lower. |
