| 摘要 |
PURPOSE:To obtain a brushless DC motor which has extremely less jitter by sequentially exciting a plurality of field windings of phases by a common pulse signal from pulse signal generating means generated in response to the rotation of the motor. CONSTITUTION:When a START signal becomes H level, a one-shot circuit 5 is triggered, an H level signal is outputted to an output terminal J for 1sec, only the base of a transistor TR14 becomes H level during this period, the H level signal fed from a PLL circuit 7 through an amplifier 8 is applied to the TR14, and a field winding L14 is excited. After such one second, the terminal J becomes L level, a ring counter 2 and a frequency malfunction detector 3 are released from resets, the output of a NOR circuit 9 becomes L level, and the bases of the TR11-14 depend upon the output of the counter 2. After reset is released, only the output Q1 becomes H level, only the TR11 is turned ON, the field winding L11 is excited, and the windings L12, L13, L14 are sequentially excited. |
