A control apparatus for controlling a plant by using a delta-sigma modulation algorithm

The invention provides a control apparatus comprising a controller for determining a manipulated variable for manipulating a controlled object so that an output of the controlled object converges to a desired value and a modulator for modulating the manipulated variable by using one of a delta-sigma modulation algorithm, a sigma-delta modulation algorithm and a delta modulation algorithm to generate a modulated signal to be applied to the controlled object. The modulator generates the modulated signal so that a center value of an amplitude of the modulated signal follows a change of the manipulated variable. Thus, the modulated signal in which the manipulated variable is reflected without any loss can be generated even when the manipulated variable changes.