| 摘要 |
PURPOSE:To prevent a motor from running away by applying command information for operating a reverse torque at the motor to a motor driving circuit when error information between the rotating speed and a control target speed of the motor becomes larger than a threshold value. CONSTITUTION:An FG pulse is output from a rotating speed detector 3 in response to the rotation of a motor 2. A microcomputer 1 obtains the rotating period of the motor 2 each time the pulse is input, and compares it with a reference value to obtain speed error information. When the speed error information exceeds a threshold value, data for applying reverse torque to the motor 2 is output to a D/A converter 4. If the speed error information does not exceed the threshold value, filter calculation executed at each timer interruption is conducted. Then, a filter output digital value is output to the converter 4. The output of the converter 4 is supplied to a motor driving circuit 5. |
