Device for frequency discrimination of electrical signals

A device for filtering and frequency discriminating an electric signal, the device comprising:

• a filter section including a band-pass filter, a first sampled resonant filter circuit and a second sampled resonant filter circuit connected in series, each of said first resonant filter circuit and said second resonant filter circuit having respective sampling control input means;
• a discriminator including a third sampled resonant filter circuit and a fourth sampled resonant filter circuit coupled in parallel to said second filter circuit and responsive to its output, each of said third resonant filter circuit and said fourth resonant filter circuit having respective sampling control input means, a first detecting means coupled to said third resonant filter circuit and responsive to its output, a second detecting means coupled to said fourth resonant filter circuit and responsive to its output, and an output differentiated amplifier coupled to said third and fourth resonant filter circuits and responsive to outputs therefrom for producing an output signal representative of the frequency of a signal received by said band pass filter;
• and
• means for producing and supplying respective sampling control signals of respective frequencies to each of said sampling control input means, said means for producing and supplying including a single high-stability oscillator feeding sampling control signal generating means.