Dual mode automatic frequency controlled oscillator system

Claim 2

A dual mode automatic phase control system comprising: means for supplying synchronizing signals to said system; a controllable oscillator wherein the frequency and phase of said oscillator signal are responsive to controlling signals; first means comprising a filter circuit and a first phase comparator having an output coupled to said filter circuit, said phase comparator being responsive jointly to said synchronizing signals and to signals occuring in timed relation with said oscillator signal for coupling a first controlling signal to said oscillator during at least a hold-in portion of operation of said system; means for detecting presence and absence of time coincidence between said synchronizing signals and a predetermined portion of said signals occurring in timed relation with said oscillator signal and for producing a mode controlling signal representative of substantially synchronized and nonsynchronized operation of said oscillator, respectively; and second means comprising a second phase comparator having an output coupled to said oscillator and responsive jointly to said synchronizing signals, to said signals occurring in timed relation with said oscillator signal and to said mode controlling signal for coupling a second controlling signal to said oscillator only during a pull-in portion of operation of said system, said filter circuit and said first and second phase comparators being arranged such that the frequency bandwidth associated with said second controlling signal is greater than that of said first controlling signal.

Claim 3

A dual mode automatic phase control system comprising: means for supplying synchronizing signals to said system; a controllable oscillator wherein the frequency and phase of said oscillator signal are responsive to controlling signals; first means comprising a filter circuit and a first phase comparator having an output coupled to said filter circuit, said phase comparator being responsive jointly to said synchronizing signals and to signals occuring in timed relation with said oscillator signal for coupling a first controlling signal to said oscillator during at least a hold-in portion of operation of said system; means for detecting presence and absence of time coincidence between said synchronizing signals and a predetermined portion of said signals occurring in timed relation with said oscillator signal and for producing a mode controlling signal representative of substantially synchronized and non-synchronized operation of said oscillator, respectively; and second means comprising a second phase comparator having an output coupled to said oscillator and responsive jointly to said synchronizing signals, to said signals occurring in timed relation with said oscillator signal and to said mode controlling signal for coupling a second controlling signal to said oscillator only during a pull-in portion of operation of said system, said filter circuit and said first and second phase comparators being arranged such that the frequency bandwidth associated with said second controlling signal is greater than that of said first controlling signal.

Claim 4

A dual mode automatic phase control system comprising: means for supplying synchronizing signals to said system; a controllable oscillator wherein the frequency and phase of said oscillator signal are responsive to controlling signals; first means comprising a filter circuit and a first phase comparator having an output coupled to said filter circuit, said phase comparator being responsive jointly to said synchronizing signals and to signals occuring in timed relation with said oscillator signal for coupling a first controlling signal to said oscillator during at least a hold-in portion of operation of said system; means for detecting presence and absence of time coincidence between said synchronizing signals and a predetermined portion of said signals occurring in timed relation with said oscillator signal and for producing a mode controlling signal representative of substantially synchronized and non-synchronized operation of said oscillator, respectively; and second means comprising a second phase comparator having an output coupled to said oscillator and responsive jointly to said synchronizing signals, to said signals occurring in timed relation with said oscillator signal and to said mode controlling signal for coupling a second controlling signal to said oscillator only during a pull-in portion of operation of said system, said filter circuit and said first and second phase comparators being arranged such that the frequency bandwidth associated with said second controlling signal is greater than that of said first controlling signal.

Claim 5

A system as defined in claim 1 wherein said first phase comparator is supplied with and is operative to sample a sawtooth reference signal representative of the phase and frequency of said oscillator during a synchronization signal interval to produce said first controlling signal.

Claim 6

A system as defined in claim 2 wherein said filter circuit exhibits a predetermined bandwidth, said filter circuit being coupled between said first phase comparator and said controllable oscillator.

Claim 7

A system as defined in claim 3 wherein said second phase comparator is operative only when said controllable oscillator is not synchronized with respect to said synchronization signals, said second phase comparator being operative under such condition to sample a sawtooth reference signal representative of the phase and frequency of said controllable oscillator during a synchronization signal interval to produce said second controlling signal.

Claim 8

A system as defined in claim 2 wherein said filter circuit in combination with said first phase comparator exhibits a relatively narrow bandwidth and a portion of said filter circuit is coupled between said second phase comparator and said controllable oscillator.

Claim 9

A system as defined in claim 5 wherein said first and second phase comparators each are direct current coupled to said oscillator and quiescent vOltages applied to said oscillator from said comparators are substantially equal.

Claim 10

A system as defined in claim 6 wherein said first and second phase comparators are substantially identical circuit configurations and are biased from a common bias source.

Claim 11

A dual mode automatic phase control system comprising: a source of synchronizing signals, a controllable oscillator whose frequency is desired to be phase locked with said synchronizing signals, means for developing a sawtooth reference signal representative of the operating phase and frequency of said controllable oscillator, a first phase comparator coupled to said source of synchronizing signals and to said means for developing a reference signal and responsive jointly to said signals to develop a first output signal in the presence of said synchronizing signals, filter means coupled between said first phase comparator and said controllable oscillator, a coincidence gate for detecting time coincidence between said synchronizing signals and a portion of said reference signal, mode control means coupled to said coincidence gate for producing a different mode control signal for substantially synchronized and non-synchronized conditions as detected by said coincidence gate, a second phase comparator coupled to said source of synchronizing signals, to said means for developing a reference signal and to said mode control means and responsive jointly to said reference signals only upon the coincident application of a synchronizing signal and a predetermined mode control signal to develop a second output signal, and means coupled from said second phase comparator to said controllable oscillator for coupling said second output signal from said second phase comparator to said controllable oscillator, the frequency bandwidth of said second output signal being greater than that of signals coupled to said oscillator from said first phase comparator by said filter means.

Claim 12

A dual mode automatic phase control system comprising: a source of synchronizing signals, a controllable oscillator whose frequency is desired to be phase locked with said synchronizing signals, means for developing a sawtooth reference signal representative of the operating phase and frequency of said controllable oscillator, a first phase comparator coupled to said source of synchronizing signals and to said means for developing a reference signal and responsive jointly to said signals to develop a first output signal in the presence of said synchronizing signals, filter means coupled between said first phase comparator and said controllable oscillator, a coincidence gate for detecting time coincidence between said synchronizing signals and a portion of said reference signal, mode control means coupled to said coincidence gate for producing a different mode control signal for substantially synchronized and non-synchronized conditions as detected by said coincidence gate, a second phase comparator coupled to said source of synchronizing signals, to said means for developing a reference signal and to said mode control means and responsive jointly to said reference signals only upon the coincident application of a synchronizing signal and a predetermined mode control signal to develop a second output signal, and means coupled from said second phase comparator to said controllable oscillator for coupling said second output signal from said second phase comparator to said controllable oscillator, the frequency bandwidth of said second output signal being greater than that of signals coupled to said oscillator from said first phase comparator by said filter means.

Claim 13

A system as defined in claim 8 wherein said filter means comprises a multi-section low pass filter network and said second output is developed across a portion of said network which has a bandwidth substantially greater than the bandwidth of said filter means associated with said first phase comparator.

Claim 14

A system as defined in claim 9 wherein said first and second phase comparators have substantially balanced direct voltage output levels.

Claim 15

A dual mode automatic phase control system according to claim 10 wherein: each of said first and second phase comparators is keyed for operation only during the occurrence of said synchronizing signals, said phase comparators providing a relatively high output impedance when not so keyed.

Claim 16

A dual mode automatic phase control system according to claim 11 wherein: said first and second phase comparators are similarly biased so as to provide substantially equal quiescent output voltages to said oscillator.