| 摘要 |
PURPOSE:To reduce the number of parts and a working time to the half of them, by providing an operating circuit supply a current, inversely proportional to the distribution of a gap flux density, through an armature coil. CONSTITUTION:A brushless motor is constituted of a rotor 10, the rotating shaft 11 of the rotor, a rotor yoke 12, an annular permanent magnet 14, consisting of 8 pieces of magnetic poles, a stator yoke 15, armature coils 16a-16d, wound in series to the stator yoke 15, a Hall element 18 and the like. In this case, an operating circuit 20, inputting an output, proportional to a gap flux density and outputted from an operational amplifier 19, and outputting a voltage, inversely proportional to the input, is provided while a commutating transistor circuit 21, consisting of transistors 22, 23, is driven and controlled by the output of the operating circuit 20. According to this method, a current, changing in inverse proportion to the density of gap flux crossing the armatures 16a, 16b, flows through the armature coils 16a, 16b of the brushless motor; therefore a torque, produced by the current and said density, becomes constant substantially regardless of the rotating position of the rotor 10. |
