| 摘要 |
PURPOSE:To provide a motor speed controller that permits rotational speed of the motor to be controlled highly accurately. CONSTITUTION:Detection signals [1]-[3] are outputted from a position detector 1 at intervals of electrical angle of 60 deg. These detection signals are inputted to a signal synthesizer 8. The detection signals [1] and [2] of these detection signals are inputted to a first exclusive OR gate of the signal synthesizer 8, and an output [4] from the first exclusive OR gate and the detection signal [3] are inputted to a second exclusive OR gate. Three speed control signals 9 are outputted from the second exclusive OR gate through an electrical angle of 360 deg.. A constant speed control circuit 4 compares the phases of these three speed control signals 9 with the phase of a reference clock 5, whereby a control signal 7 is outputted to a logic circuit 2a of a motor drive circuit 2. Such a construction makes it possible to correct speed of the motor three times through 360 deg., and hence the rotation speed of the motor can be controlled highly accurately. |
