| 摘要 |
PURPOSE:To prevent the phase output of a synchronous motor from varying due to the stopping position of a rotor by loading the position code in a counter by the varying point detecting output of a varying point detector and the counting the rotary pulse. CONSTITUTION:A pulse encoder which outputs a position code IP and rotary pulses AP, BP, and a varying point detector 31 which detects the varying point of the position code IP are provided. Further, an up-down counter 36 which loads the code IP and counts the rotary pulse and converters 37a, 37b which convert the counted values to analog voltages in response to the cos theta, sin theta are provided. After the position code is loaded in the counter by the varying point detection output of the varying point detector, the rotary pulse is counted. In this manner, even if the rotor of a synchronous motor is stopped at any position, the rotary pulse can be counted from the same position after restarting, and the phase output can be always maintained constantly irrespective of the stopping position. |
