| abstract |
A programmed irrigation controller automatically computes durations for, schedules, and controls split irrigation cycles at up to eight watering stations. The controller is manually entered with high-level information regarding soil type, terrain, and irrigation system watering head type, and also with a total irrigation time, for each station. The maximum "on" time duration for each individual split irrigation cycle, and a minimum "off" time duration, are determined from the high-level information input by table lookup. The controller computes the number of irrigation cycles at each station as its total irrigation time divided by its maximum "on" time duration. The controller schedules composite irrigation cycles for all stations so that no station overwaters within a single irrigation cycle or upon successive irrigation cycles that are too closely time proximate. Exclusionary time-of-day intervals that specify when no watering will occur can be inserted within the schedules. A water budgeting factor proportionately controls the numbers of split irrigation cycles. Special overlaid schedules provide useful special irrigation sequences/durations such as one-time deep soak, periodic deep soak, or syringe cycles. The programmed irrigation control for a single station may be copied for the control of additional stations. |