| 摘要 |
PROBLEM TO BE SOLVED: To enables current flowing in position detecting means to be constant.SOLUTION: A brushless DC motor which has a stator with a three-phase coil 1 and a rotor 3 having an annular permanent magnet has an inverter circuit 9 comprising plural switching elements and plural rectifying elements that supply a driving voltage to the three-phase coil 1 to supply driving current, three position detecting means 10 of three phases which detect the position and speed of the rotor 3, and are arranged at an interval of 120° in electrical angle, driving signal generating means 12 for generating an output signal for driving the inverter circuit 9 on the basis of output signals of the three position detecting means 10, and position detection current adjusting means 11 for switching the output so that the current flowing in the three position detecting means 10 is constant, the position detection current adjusting means being connected to one end of the inputs of the three position detecting means 10 and either a power source 14 or an earth 15 in series.SELECTED DRAWING: Figure 2 |
