| 摘要 |
PURPOSE:To simply make the rotational angle of a motor agree with a target value by feeding an armature current the polarity of which is in accordance with the sign of a calculated manipulated variable, and the pulse width of which is equal to the absolute value of the manipulated variable. CONSTITUTION:A manipulated variable to output is calculated from the difference between a rotational angle detected by a rotational angle sensor 7 and a target value. The absolute value of the manipulated variable is stored in a register 5n, and a counter 5k is started. Either of ports A1 and A2 is placed in the LOW level depending on whether the manipulated variable is positive or negative. When the port A1 or A2 is placed in the LOW level, the normal or reverse rotation signal is fed to a motor M. The counter 5k is making a clock count. When its count agrees with the value on the register 5n, a comparator 5m generates an interrupt signal INT 3. An interrupt routine triggered by the interrupt signal places both of the ports A1 and A2 in the HIGH level, and output to the motor M is interrupted. This makes it possible to output a driving current the duration of which corresponds to the manipulated variable. |
