Phase and frequency comparator for signals unavailable simultaneously

Claim 2

Apparatus responsive to the phase and frequency of an alternating signal provided by a signal means, comprising: a wave shaper connected to the signal means for converting alternating signal to a signal having a predetermined wave form and a frequency corresponding to the alternating signal; a storage counter connected to the wave shaper for converting the signal having a predetermined wave form to a corresponding charge; the storage counter including a first circuit connected to the wave shaper for converting a signal therefrom in one sense to a charge in the one sense, a second circuit connected to the wave shaper for converting a signal therefrom in an opposite sense to a charge in the opposite sense, and a capacitor connected to the first and second circuits for accumulating a charge corresponding to the frequency difference between the signals in the one and the opposite sense; an integrator connected to the storage counter for integrating the charge therefrom; an oscillator connected to the integrator and responsive to the integrated charge for providing a pulse train having a corresponding frequency; the oscillator connected in feedback relation to the storage counter for affecting the storage counter so that the output therefrom is zero when the frequency of the pulse train equals the frequency of the signal having a predetermined wave form; and said counter affecting the integrator when said counter output is zero so that the integrator output is constant, and whereupon the frequency of the oscillator pulse train is likewise constant.

Claim 3

Apparatus as described by claim 1, including: a signal sensor connected to the wave shaper for sensing the absence of a signal therefrom; and switching means connected to the signal sensor and to the integrator and connected to ground, and operated by the signal sensor when the wave shaper signal is absent for connecting the integrator to ground to render the oscillator pulse train frequency constant.

Claim 4

Apparatus as described by claim 1, including: a synchronizer connected to the wave shaper and to the oscillator, and responsive to the wave shaper signal for synchronizing the oscillator to provide a constant phase relation between the signal from the wave shaper and the pulse train from the oscillator.

Claim 5

Apparatus as described by claim 1, wherein: the capacitor is alternately charged and discharged by the signals in the one and the opposite senses.

Claim 6

A phase and frequency comparator for a plurality of input signals having different phases and frequencies provided by a corresponding plurality of signal sources, and which signals are unavailable simultaneously, said comparator comprising: a channel for each of the input signals, each channel including a wave shaper connected to the corresponding signal source for providing a signal having a predetermined wave form and a frequency corresponding to the input signal, a storage counter connected to the wave shaper for converting the signal therefrom to a corresponding charge, the storage counter including a first circuit connected to the wave shaper for converting a signal therefrom in one sense to a charge in the one sense, a second circuit connected to the wave shaper for converting a signal therefrom in an opposite sense to a charge in the opposite sense, and a capacitor connected to the first and second circuits for accumulating a charge corresponding to the frequency difference between the signals in the one and the opposite senses, an oscillator connected to the storage counter and driven thereby and connected in feedback relation to the counter so that the counter output is zero when the oscillator output frequency equals the predetermined wave form frequency, and means connected to the counter and to the oscillator for rendering the oscillator output constant when the counter output is zero; and means connected to the oscillators in each of the channels for comparing the phase and frequency of the oscillator outputs, said phase and frequency corresponding to that of the corresponding input signals.

Claim 7

A phase and frequency comparator for a plurality of input signals having different phases and frequencies provided by a corresponding plurality of signal sources, and which signals are unavailable simultaneously, said comparator comprising: a channel for each of the input signals, each channel including a wave shaper connected to the corresponding signal source for providing a signal having a predetermined wave form and a frequency corresponding to the input signal, a storage counter connected to the wave shaper for converting the signal therefrom to a corresponding charge, the storage counter including a first circuit connected to the wave shaper for converting a signal therefrom in one sense to a charge in the one sense, a second circuit connected to the wave shaper for converting a signal therefrom in an opposite sense to a charge in the opposite sense, and a capacitor connected to the first and second circuits for accumulating a charge corresponding to the frequency difference between the signals in the one and the opposite senses, an oscillator connected to the storage counter and driven thereby and connected in feedback relation to the counter so that the counter output is zero when the oscillator output frequency equals the predetermined wave form frequency, and means connected to the counter and to the oscillator for rendering the oscillator output constant when the counter output is zero; and means connected to the oscillators in each of the channels for comparing the phase and frequency of the oscillator outputs, said phase and frequency corresponding to that of the corresponding input signals.

Claim 8

A comparator as described by claim 5, wherein the means connected to the counter and to the oscillator for rendering the oscillator output constant when the counter output is zero includes: an integrator connected to the counter for integrating the charge therefrom and affected by the zero counter output for providing a constant integrator output.

Claim 9

A comparator as described by claim 5, including: a signal sensor connected to the wave shaper for sensing the absence of a signal therefrom; and a switching device connected to the signal sensor and to the means connected to the counter and to the oscillator for rendering the oscillator output constant when the counter output is zero, and operated by the signal sensor for connecting said means to ground.