PURPOSE: To obtain the output signal of a given amplitude independently of duty of input signal by constituting with multipliers, various operators and adders.

CONSTITUTION: The output signal of a given amplitude can be obtained independently of the duty of input signal, by gain control with the dividend by the time average of the absolute value or, positive or negative value of the difference between the time average of output signal and the output signal itself, and the duty of input or output or output signal as a divisor, not by direct use of the time average. The required duty can be obtained with a simple constitution by use of the adder where the difference between the time average of input or output signal and the input or output signal itself is inputted and when the difference is positive, output "1" is made and when negative or zero, "0" is outputted, to obtain the duty of input or output signal.