Signal discriminating apparatus

Claim 1

Median value signal selecting apparatus for receiving an odd number N of analog input signals and for selecting the median valued one of the input signals, the apparatus including (N+1)/2 extreme value selector circuits each of which comprises: N comparator amplifiers each having a first and second input and an output and being operable to form at its output a signal having a magnitude and polarity dependent upon the relative values of signals applied to its first and second inputs, the first inputs of the comparator amplifiers of each selector circuit being connected for receiving respective ones of said analog input signals, a common signal line connected to the second input of each comparator amplifier, and N first diodes connected between the outputs of respective ones of the comparator amplifiers and said common signal line for passing thereto, and hence to the second input of each comparator amplifier, the output signal formed by that one of the comparator amplifiers which receives an extreme valued one of the analog input signals whereby each other comparator amplifier forms an output signal having a polarity opposite to that of the output signal formed by said one comparator amplifier; at least each of all but a first one of said extreme value selector circuits further comprising N second diodes each connected in series opposition with a respective corresponding one of the first diodes between the output of the respective corresponding comparator amplifier and said common signal line, each second diode being coupled to the output of that one of the comparator amplifiers, in a respective one of the other selector circuits, which receives the same analog input signal as said respective corresponding comparator amplifier.