| 摘要 |
PURPOSE:To facilitate a circuit design and to reduce the number of parts by supplying a pulse-modulated drive signal only to one transistor of a push-pull amplifier by employing a bipolar drive type. CONSTITUTION:The outputs of Hall sensors 11-13 opposed to stator coils 31- 33 are input through amplifiers 51-53 to comparator 61-63, and drive signals pulse-width-modulated in response to the output signals of the Hall sensors 11- 13 are respectively output from the comparators 61-63. The drive signals are supplied only to one 21a-23a of transistors 21a-23a, 21b-23b which form push- pull amplifiers. The transistors 21b-23b receive signals in response to the output signals of the sensors 11-13 as they are. The energizations of the coils 31- 33 are controlled by the transistors 21a-23a, 21b-23b. |
