Abstract: Apparatus which automatically measures the range and the lower and upper peak values of an unknown signal which varies periodically as a function of time. More specifically, an unknown time varying input signal is applied through a programmable attenuator to one input of a comparator. A direct current voltage which changes in equal incremental steps between predetermined levels is applied to the other input of the comparator. When coincidence occurs an output signal is developed by the comparator responsive thereto. The output signal thus developed is utilized to maintain the attenuator at the range level to which it was set when the coincidence was detected and also causes the reference level applied to the comparator to sequentially change in such a manner as to ascertain the lower and upper peak values of the applied signal.

Abstract: A voltage level display circuit for providing a display of the magnitude of the reference voltage level to a comparator circuit. A microprocessor is responsive to an input command signal to generate a digital reference voltage level which is converted by a digital to analog converter to an analog signal which is coupled to a reference voltage input of a comparator which compares the reference voltage level with an applied signal. A digital display is coupled to the output of the microprocessor to simultaneously provide a visual indication of the output of the microprocessor while generating the digital reference voltage signal.