Switching mode control circuits

Claim 2

In a color television receiver including a plurality of color demodulators, and apparatus, associated with the utilization of at least one of said demodulators, subject to switching, line by line, between first and second operating conditions, and wherein proper operation of said color television receiver requires that said line by line switching of said apparatus occur in a sense matching a predetermined sense of line by line alteration of signals received by said color television receiver, a switching control system comprising the combination of: means for deriving from said received signals a half line frequency waveform indicative of the sense of said line by line signal altEration; bistable flip-flop circuit means providing, in response to line frequency triggering pulses, half line frequency switching waves for controlling the line by line switching of said apparatus between said first and second operating conditions; a phase detector responsive to said derived half line frequency waveform and to said half line frequency switching waves for developing a control voltage of a first value when the sense of said switching correctly matches the sense of said signal alteration and of a value differing from said first value in the absence of said correct matching of senses; and means responsive to the control voltage developed by said phase detector for altering the operation of said flip-flop circuit means, said altering means being rendered inoperative whenever the control voltage developed by said detector is of said first value.

Claim 3

A switching control system in accordance with claim 1 wherein said operation altering means comprises means for disabling said flip-flop circuit means whenever said control voltage value significantly differs from said first value.

Claim 4

In a color television receiver including a plurality of color demodulators, and apparatus, associated with the utilization of at least one of said demodulators, subject to switching, line by line, between first and second operating conditions, and wherein proper operation of said color television receiver requires that said line by line switching of said apparatus occur in a sense matching a predetermined sense of line by line alteration of signals received by said color television receiver, a switching control system comprising the combination of: bistable flip-flop circuit means providing, in response to a line frequency triggering pulse input, half line frequency switching waves for controlling the line by line switching of said apparatus between said first and second operating conditions; means responsive to said received signals and to said half line frequency switching waves for developing a control voltage of a first value when the sense of said switching correctly matches the sense of said signal alteration and of values differing from said first value in the absence of said correct matching of senses; and means responsive to the control voltage output of said developing means for altering the operation of said flip-flop circuit means, said altering means being rendered inoperative whenever the control voltage developed by said detector is of said first value.

Claim 5

In a color television receiver including a plurality of color demodulators, and apparatus, associated with the utilization of at least one of said demodulators, subject to switching, line by line, between first and second operating conditions, and wherein proper operation of said color television receiver requires that said line by line switching of said apparatus occur in a sense matching a predetermined sense of line by line alteration of signals received by said color television receiver, a switching control system comprising the combination of: bistable flip-flop circuit means providing, in response to a line frequency triggering pulse input, half line frequency switching waves for controlling the line by line switching of said apparatus between said first and second operating conditions; means responsive to said received signals and to said half line frequency switching waves for developing a control voltage of a first value when the sense of said switching correctly matches the sense of said signal alteration and of values differing from said first value in the absence of said correct matching of senses; and means responsive to the control voltage output of said developing means for altering the operation of said flip-flop circuit means, said altering means being rendered inoperative whenever the control voltage developed by said detector is of said first value.

Claim 6

In a color television receiver including deflection circuitry providing a source of line frequency triggering impulses, a plurality of color demodulators, a reference color oscillator, switching apparatus coupled to said oscillator for switching the reference oscillation input to one of said demodulators, line by line, between first and second mutually opposite phase conditions, and wherein proper operation of said color television receiver requires that said line by line color occur in a sense matching a predetermined sense of line by line alteration of signals received by said colour television receiver, a switching control system comprising the combination of: a color oscillator synchronizing circuit including means for deriving from said received signals a half line frequency waveform indicative of the sense of said line by line signal alteration; bistable flip-flop circuit means providing, in response to line frequency triggering impulses from said source, half line frequency switching waves for controlling the line by line switching of reference oscillation input between said first and second mutually opposite phase conditions; a phase detector responsive to said derived half line frequency waveform and to said half line frequency switching waves for developing a control voltage of a first value when the sense of said switching correctly matches the sense of said signal alteration and of values differing from said first value in the absence of said correct matchIng of senses; and means responsive to the control voltage developed by said phase detector for altering the operation of said flip-flop circuit means, said altering means being rendered inoperative whenever the control voltage developed by said detector is of said first value.

Claim 7

In a color television receiver including deflection circuitry providing a source of line frequency triggering impulses, a plurality of color demodulators, a reference color oscillator, switching apparatus coupled to said oscillator for switching the reference oscillation input to one of said demodulators, line by line, between first and second mutually opposite phase conditions, and wherein proper operation of said color television receiver requires that said line by line color occur in a sense matching a predetermined sense of line by line alteration of signals received by said colour television receiver, a switching control system comprising the combination of: a color oscillator synchronizing circuit including means for deriving from said received signals a half line frequency waveform indicative of the sense of said line by line signal alteration; bistable flip-flop circuit means providing, in response to line frequency triggering impulses from said source, half line frequency switching waves for controlling the line by line switching of reference oscillation input between said first and second mutually opposite phase conditions; a phase detector responsive to said derived half line frequency waveform and to said half line frequency switching waves for developing a control voltage of a first value when the sense of said switching correctly matches the sense of said signal alteration and of values differing from said first value in the absence of said correct matchIng of senses; and means responsive to the control voltage developed by said phase detector for altering the operation of said flip-flop circuit means, said altering means being rendered inoperative whenever the control voltage developed by said detector is of said first value.

Claim 8

A switching control system in accordance with claim 4, wherein said operation altering means includes a diode normally biased for nonconduction, control means responsive to said control voltage developed by said detector for rendering said diode conducting when said detector develops a control voltage of values differing significantly from said first value, and means coupling said diode to said flip-flop circuit means in such manner that conduction of said diode serves to disable said flip-flop circuit means.

Claim 9

A switching control system in accordance with claim 4 wherein said deflection circuitry also provides a source of field frequency triggering impulses, a gate coupled between said source of field frequency triggering impulses and said flip-flop circuit means, and control means responsive to said control voltage developed by said detector for causing said gate to block passage of said field frequency triggering impulses when said detector develops a control voltage of said first value indicating presence of correct matching of said senses and for causing said gate to permit passage of a field frequency triggering impulse to reset said flip-flop circuit means develops a control voltage of said differing value.

Claim 10

Apparatus in accordance with claim 3 wherein said altering means comprises means for precluding said bistable flip-flop means from responding to said line frequency triggering impulses.

Claim 11

Apparatus in accordance with claim 3 wherein said altering means comprises an additional source of resetting pulses for said bistable flip-flop circuit means, and means for applying said resetting pulses to said bistable flip-flop circuit means, said resetting pulse applying means being rendered inoperative whenever the control voltage developed by said detector is of said first value.