Phase comparator providing dc output as a function of variable phase between two inputs

Claim 2

In a system for producing a control signal which varies according to the sense and extent of the phase displacement between variable phase recurring command pulses and the negative-going zero crossing of a regularly recurring variable phase signal, the combination comprising a. a bistate device having stable ''''0'''' and ''''1'''' states, b. means for setting said bistate device to its ''''1'''' state in response to each of said command pulses, c. means for resetting said bistate device to its ''''0'''' state in response to each positive-going zero crossing of said recurring signal, d. means for producing a first signal having a first predetermined value during those periods when said bistate device is in its ''''1'''' state and said recurring signal is concurrently in a positive half cycle, e. means for producing a second signal having a predetermined value during those periods when said bistate device is in its ''''0'''' state and said recurring signal is concurrently in a negative half cycle, f. said first and second signals thereby being modulated in width and occurring exclusively of one another, and g. means for producing a smoothly varying control signal corresponding to the average value of that one of the first and second signals which is occurring.

Claim 3

In a system for producing a control signal which varies according to the sense and extent of phase displacement between successive time-phased command pulses and successive negative-going zero crossings of a cyclically recurring signal, the combination comprising a. a bistate device having stable ''''0'''' and ''''1'''' states, b. means for setting said bistate device to its ''''1'''' state in response to each of said command pulses, c. means for resetting said bistate device to its ''''0'''' state in response to each positive-going zero crossing of said recurring signal, d. positive and negative constant magnitude signal generating means settable to off, positive on, and negative on states, e. means for causing said generating means to produce a negative output signal during those periods when said bistate device is in its ''''1'''' state and said recurring signal is concurrently in a positive half cycle, f. means for causing said generating means to produce a positive output signal during those periods when said bistate device is in its ''''0'''' state and said recurring signal is concurrently in a negative half cycle, and g. means for filtering the Output signals of said generating means to produce a smoothed, variable control signal.

Claim 4

In a system for producing a control signal which varies according to the sense and extent of phase displacement between successive time-phased command pulses and successive negative-going zero crossings of a cyclically recurring signal, the combination comprising a. a bistate device having stable ''''0'''' and ''''1'''' states, b. means for setting said bistate device to its ''''1'''' state in response to each of said command pulses, c. means for resetting said bistate device to its ''''0'''' state in response to each positive-going zero crossing of said recurring signal, d. positive and negative constant magnitude signal generating means settable to off, positive on, and negative on states, e. means for causing said generating means to produce a negative output signal during those periods when said bistate device is in its ''''1'''' state and said recurring signal is concurrently in a positive half cycle, f. means for causing said generating means to produce a positive output signal during those periods when said bistate device is in its ''''0'''' state and said recurring signal is concurrently in a negative half cycle, and g. means for filtering the Output signals of said generating means to produce a smoothed, variable control signal.

Claim 5

In a system for signalling the sense and extent of phase angle between successive time-phased command pulses and successive negative-going zero crossings of a regularly recurring alternating signal, said system comprising in combination a. tristate means for generating an output signal which is (1) zero, (2) positive, or (3) negative with the same magnitude when set to its first, second, or third states, b. means for setting said generating means to its third state in response to a command pulse occurring prior to a negative-going zero crossing during each cycle of said recurring signal and resetting said generating means to its first state when such zero crossing occurs, c. means for setting said generating means to its second state in response to a negative-going zero crossing of said recurring signal occurring prior to a command pulse during each cycle of said recurring signal and for resetting said generating means to its first state when such command pulse occurs, and d. low pass filter means for producing a control signal which varies in magnitude and polarity according to the average value of said output signal.

Claim 6

In a system for signalling the sense and extent of phase angle between successive time-phased command pulses and successive negative-going zero crossings of a regularly recurring alternating signal, said system comprising in combination a. tristate means for generating an output signal which is (1) zero, (2) positive, or (3) negative with the same magnitude when set to its first, second, or third states, b. means for setting said generating means to its third state in response to a command pulse occurring prior to a negative-going zero crossing during each cycle of said recurring signal and resetting said generating means to its first state when such zero crossing occurs, c. means for setting said generating means to its second state in response to a negative-going zero crossing of said recurring signal occurring prior to a command pulse during each cycle of said recurring signal and for resetting said generating means to its first state when such command pulse occurs, and d. low pass filter means for producing a control signal which varies in magnitude and polarity according to the average value of said output signal.

Claim 7

In a system for signalling the sense and extent of phase angle between time-phased command pulses and the negative-going zero crossing of a regularly recurring alternating signal, the combination comprising a. a flip-flop having first and second stable states and means for producing a pair of mutually complementary signals indicative of the prevailing state of said flip-flop, b. means for setting said flip-flop to its second state in response to each of said command pulses, c. means for resetting said flip-flop to its first state in response to each positive-going zero crossing of said recurring signal, d. means connected to receive said recurring signal for generating a square wave signal and its complement respectively in phase with and 180* out of phase with said recurring signal, e. means including a first AND gate connected to receive said square wave signal and one output signal of said flip-flop for producing a signal of a first polarity during those periods when said flip-flop is in its second state and said recurring signal is concurrently in a positive half cycle. f. means including a second AND gate connected to receive said square wave complement and the other output signal of said flip-flop for producing a signal of a second polarity during those periods when said flip-flop is in its first state and said recurring signal is concurrently in a negative half cycle, g. said first and second signals being time-width modulated according to the extent of the phase angle and occurring respectively when the phase error is of one sense or the other, and h. means for producing a control signal which smoothly varies according to the average value of the first and second polarity signals.

Claim 8

In a system for signalling the sense and extent of phase angle between time-phased command pulses and the negative-going zero crossing of a regularly recurring alternating signal, the combination comprising a. a flip-flop having first and second stable states and means for producing a pair of mutually complementary signals indicative of the prevailing state of said flip-flop, b. means for setting said flip-flop to its second state in response to each of said command pulses, c. means for resetting said flip-flop to its first state in response to each positive-going zero crossing of said recurring signal, d. means connected to receive said recurring signal for generating a square wave signal and its complement respectively in phase with and 180* out of phase with said recurring signal, e. means including a first AND gate connected to receive said square wave signal and one output signal of said flip-flop for producing a signal of a first polarity during those periods when said flip-flop is in its second state and said recurring signal is concurrently in a positive half cycle. f. means including a second AND gate connected to receive said square wave complement and the other output signal of said flip-flop for producing a signal of a second polarity during those periods when said flip-flop is in its first state and said recurring signal is concurrently in a negative half cycle, g. said first and second signals being time-width modulated according to the extent of the phase angle and occurring respectively when the phase error is of one sense or the other, and h. means for producing a control signal which smoothly varies according to the average value of the first and second polarity signals.