| 摘要 |
<p>A feedback automatic control apparatus opens or closes a gate by making a feedback control such that the water level of a dam may correspond with a target value. More specifically, a control portion (1) included in a feedback automatic control apparatus provides a first comparator 2 with a target value of the water level of a dam on the occasion of a start of control. The comparator compares the actual water level of the dam and the target value, thereby to provide a deviation value. At the same time, the control portion sets in a dead zone setting portion (7) a first dead zone having a relatively wide width contiguous to the target value. A second comparator (5) compares a first dead zone set in the dead zone setting portion and the deviation value, thereby to control the gate by a gate drive circuit (6) to open or close the same, such that the deviation value may be smaller than the width of the first dead zone. When the timer circuit (8) counts a predetermined time, the control portion sets in the dead zone setting portion a second dead zone of the width narrower than the first dead zone. Thereafter the second comparator compares the second dead zone and the deviation value, thereby to open or close the gate by the gate drive circuit, such that the deviation value may be smaller than the width of the second dead zone. </p> |
