| 摘要 |
PURPOSE:To reduce the number of elements, by arranging non-polarity sections for setting the detection output of magnetism-sensitive elements to be zero, on pole sections confronted with the magnetism-sensitive elements of a rotor. CONSTITUTION:A brushless DC motor is composed of a rotor 10, a stator core 3, stator coils 6r-6t, hole ICH1-H2, and the like. In this case, so far as the rotor 10 is concerned, on the periphery of a laminated core, four poles 1a-1d as permanent magnets are formed, and recessed sections 11a-11d as non- polarity sections are formed. A drive circuit 13 is composed of a gate circuit 14 for generating the output of conduction change-over signal based on detection signal from the output terminals a-d of said hole ICH1-H2, and a switching circuit 15. By the circuits, as hole element detecting signal, polarities N, S are detected, and detection signal for detecting non-polarity is obtained. Based on three sorts of the detection signals, from the drive circuit 13 to a plurality of the stator coils 6r-6t, driving current with a specified conduction angle is fed to be switched in order. |
