Patent US 3,974,433

An automatic control apparatus comprises a means for detecting deviation of an actual value from a target value of a controlled quantity for the control operations and a damping feedback means, at least one of which means is provided with an element having a saturation characteristic. Predetermined relations are established between the input value to saturate the output of the detector means and the input value to saturate the output of the damping feedback means to thereby enhance mainly the response of operation for the control in one direction, while for the control operation in the other direction, stability is improved.