Device for distinguishing between a first and a second frequency of signals

摘要

This simple device comprises a pulse shaping stage (1) which is supplied by the signals and which supplies from these a pulse-shaped signal (on 6) with pulses of a particular duration (T) at a frequency corresponding to the frequency of the signals, an integration stage (2) for forming a mean value of the pulse-shaped signal (on 6) and a comparison stage (3) for comparing the mean value with a reference value and outputting an identification signal (on 8) as determined by the result of the comparison. <IMAGE>