Abstract: An improved switch controller and related method for regulating the supply voltage of a solar cell array. The switch controller includes at least two shift registers, with additional shift registers concatenated as required by the size of the array. Each of the shift registers controls segments of the solar cell array having increasingly larger outputs, with the first shift register providing fine resolution control of the supply voltage and the second and additional shift registers providing increasingly-coarser resolution control of the supply voltage. The improved switch controller provides improved switching characteristics for the regulation of the supply voltage of a solar cell array.