Abstract: A control apparatus is disclosed for use in an irrigation system having a plurality of conduit sections pivotally joined at sets of adjacent ends and selectively operable drivers for moving the conduit sections in a forward direction. Each control apparatus maintains the relative alignment of a pair of joined conduit sections. It includes a conduit misalignment indicator having two indicating portions which are directly relatable in position to the relative alignment of the two conduit sections. Further, Hall-effect sensors positioned on one indicating portion opposite from a magnet positioned on the other indicating portion provide for sensing of the relative alignment of the conduit sections. A digital electrical circuit converts the sensor signals into a control signal for initiating operation of the driver when the conduit sections are in lagging misalignment and terminating operation when the conduit sections are in leading misalignment.