| 摘要 |
PURPOSE:To flow a current corresponding to a target value to an actuator by comparing the target current value and the actuator current value with each other and outputting the comparison result to a computer to change the driving current of the actuator. CONSTITUTION:A computer CPU 10 supplies first a target current value It to a D/A converter 20 and gives the target current value converted to an analog signal to a comparator 21. Thereafter, the CPU 10 outputs an actuator driving command signal Io; and when a current is flowed to the actuator, the turn-on time of a transistor TR 15 is changed in accordance with the magnitude of the command signal Io, and the average value of the current flowed to a coil 16 is changed by this change. The current is smoothed by a current detecting resistance R and a filter 17 and is supplied to the comparator 21 is detection current Ir through an amplifier 18. The target current value It and the detection current Ir are compared with each other by the comparator 21, and the CPU 10 changes the actuator driving command signal Io while observing a compari son result Sc to flow the current corresponding to the target value. |
