| 摘要 |
PURPOSE:To make a complicated controlling electronic circuit unnecessary and to produce inexpensively a device in a small size by not changing continuously the current flowed to a motor but changing the current to switch it to three stages. CONSTITUTION:Conditions which designate currents flowed to a motor by switching are determined by a value Q of an equation I . The value Q is obtained in such a way that the value derived by subtracting a present value theta from a command value thetac is added with the result of multiplying a time-differenciated value of theta by an absolute value of theta and by a constant KV, and said overall value is multiplied by a constant KF. With respect to the calculation of the value Q, a rotative angular speed is detected by a speed detector C, and its absolute value is obtained by an absolute value circuit 13, and they are multiplied in a multiplier 14. A multiplier 15 multiplies this multiplication resultant value by the constant KV. A subtractor 16 subtracts the angle from the value thetaC, and a subtractor 17 adds this subtraction value and said value attained by multiplication of the constant KV, and this addition resultant value is multiplied by the constant KF by a multiplier 18. A motor current switch 12 performs the switching operation so that the motor is driven to increase the value theta when the value Q is larger than a constant v1 and the motor is driven to reduce the value theta when the value Q is smaller than a constant v2 and the driving force is not generated when the value Q is larger than the constant v2 and is smaller than the constant v1. |
