Frequency comparator system

Claim 2

A circuit for comparing input frequency waves to locally generated frequency waves comprising: first means responsive to each wave of said input frequency waves for generating first pulses of a given number, of a first polarity, of a given magnitude and of fixed duration, second means responsive to each wave of said locally generated frequency waves for generating second pulses of said given number, of a polarity opposite to said first polarity, of a given magnitude and of said fixed duration, and means coupled to said first and second means for algebraically summing the magnitudes of said first and second pulses over a time period to provide an output signal proportional to the difference between said input frequency and said locally generated frequency.

Claim 3

A circuit for comparing input frequency waves to locally generated waveS comprising: means responsive to said input frequency waves for squaring said waves, a first monostable multivibrator responsive to each wave of said squared input frequency waves for providing a given number of first pulses of fixed duration and of a given magnitude, means responsive to said locally generated frequency waves for squaring said waves, a second monostable multivibrator responsive to each wave of said squared locally generated frequency waves for providing second pulses of said given number, of said fixed duration and of a given magnitude, means for inverting the polarity of said second pulses relative to said first pulses, and means coupled to said first and second monostable multivibrators for algebraically summing the magnitudes of said first and second pulses over a time period to provide an output signal proportional to the difference between said input frequency and said locally generated frequency.

Claim 4

A circuit for comparing input frequency waves to locally generated waveS comprising: means responsive to said input frequency waves for squaring said waves, a first monostable multivibrator responsive to each wave of said squared input frequency waves for providing a given number of first pulses of fixed duration and of a given magnitude, means responsive to said locally generated frequency waves for squaring said waves, a second monostable multivibrator responsive to each wave of said squared locally generated frequency waves for providing second pulses of said given number, of said fixed duration and of a given magnitude, means for inverting the polarity of said second pulses relative to said first pulses, and means coupled to said first and second monostable multivibrators for algebraically summing the magnitudes of said first and second pulses over a time period to provide an output signal proportional to the difference between said input frequency and said locally generated frequency.

Claim 5

The combination as claimed in claim 2 wherein said summing means includes a capacitor, a current source coupled between said first monostable multivibrator and said capacitor for charging said capacitor in a first sense and a current sink coupled between said second monostable multivibrator and said capacitor for discharging said capacitor and charging said capacitor in a second sense.

Claim 6

The combination as claimed in claim 3 wherein said summing circuit further includes a filter coupled to said capacitor for smoothing the output from said capacitor.

Claim 7

The combination as claimed in claim 4 wherein said summing means further includes a d.c. amplifier coupled to the output of said filter.

Claim 8

In combination: a first comparator circuit for comparing input frequency waves to locally generated frequency waves, said first comparator comprising: means responsive to said input frequency waves for squaring said waves, a first monostable multivibrator responsive to each wave of said squared input frequency waves for providing first pulses of a given number and of a fixed duration, means responsive to said locally generated frequency waves for squaring said waves, a second monostable multivibrator responsive to each wave of said squared locally generated frequency waves for providing second pulses of said given number and of said fixed duration, means coupled to said first and second monostable multivibrators for summing said first and second pulses to provide an output that reflects the difference between said input frequency and said locally generated frequency, switch means having a pair of input terminals and an output terminal, said first input terminal coupled to the output of said summing means of said first comparator, said switch means normally coupling signals applied to said first input terminal to said switch means output terminal, a phase locked loop detector coupled at one input end to said locally generated frequency waves and said input frequency waves for providing detected phase differences, said phase locked loop detector coupled at the output end to said second input terminal of said switch means, a second comparator coupled between the output of said first comparator and said switch means for causing said switch means to change state and couple only signals at said second input terminal of said switch means when the output from said first comparator indicates no difference between said input frequency and said locally generated frequency.

Claim 9

In combination: a first comparator circuit for comparing input frequency waves to locally generated frequency waves, said first comparator comprising: means responsive to said input frequency waves for squaring said waves, a first monostable multivibrator responsive to each wave of said squared input frequency waves for providing first pulses of a given number and of a fixed duration, means responsive to said locally generated frequency waves for squaring said waves, a second monostable multivibrator responsive to each wave of said squared locally generated frequency waves for providing second pulses of said given number and of said fixed duration, means coupled to said first and second monostable multivibrators for summing said first and second pulses to provide an output that reflects the difference between said input frequency and said locally generated frequency, switch means having a pair of input terminals and an output terminal, said first input terminal coupled to the output of said summing means of said first comparator, said switch means normally coupling signals applied to said first input terminal to said switch means output terminal, a phase locked loop detector coupled at one input end to said locally generated frequency waves and said input frequency waves for providing detected phase differences, said phase locked loop detector coupled at the output end to said second input terminal of said switch means, a second comparator coupled between the output of said first comparator and said switch means for causing said switch means to change state and couple only signals at said second input terminal of said switch means when the output from said first comparator indicates no difference between said input frequency and said locally generated frequency.