A method for feeding a shingled stack of sheet material to a downstream processing device includes the step of identifying a discontinuity in the shingled stack of sheet material wherein the discontinuity has a length dimension from an aft end of a downstream portion of the shingled sheet material to a forward end of an upstream portion of the shingled sheet material. The resultant output currents are converted into voltage values by resistors selected by a selector. A dither value is also generated from a dither matrix, and the dither value is combined with the extent of overlap to produce an output value. A selector selects any one of the second timing signals depending on a detection result provided by the detection circuit.