Abstract: A touch sensitive system comprising a clock (30) for generating a clocking signal supplied to a plurality of circuits each including one of the touch plates (12, 14, 15, 16, 17) for generating a varying capacitance value depending upon whether or not the plate is touched or untouched. The change in capacitance of each circuit varies the time duration of the generated output signal of that circuit. A flipflop (18, 19, 20, 21, 22) for each circuit receives a reference signal from a reference circuit (61) and the output signal from the associated circuit and supplies to an associated output terminal (24, 25, 26, 27, 28) a digital signal indicating which plate or plates are touched.