AUTOMATIC IRRIGATION SYSTEM AND CONTROL DEVICE THEREFOR

摘要

An irrigation system control device (20) is provided which is adapted to be buried in the soil underground for controlling the operation of a flow control valve of an automatic irrigation system in accordance with the moisture content of the soil surrounding the control device (20). The control device (20) is in the form of a receptacle (21) having an upper part with a perforated side wall (23) and a lower imperforate part (28) for collecting water and moisture which pass from the soil through the perforated side wall (23) into the receptacle (21). The receptacle (21) contains a float-operated switch (40) which is arranged to open the flow control valve of the irrigation system when the water collected in the receptacle (21) falls below a predetermined lower level (70) and the float-operated switch (40) is adapted to close the flow control valve when the water collected in the receptacle (21) rises above a predetermined upper level (71).