Television receiver ferroresonant power supply disabling circuit

Claim 2

A television display system that includes a ferroresonant power supply with a protection circuit for disabling normal operation of a load circuit within said television display system during a fault operating condition, comprising: a source of alternating input voltage; a magnetizable core including a saturable core section; means coupled to said source for developing an exciting current that generates a magnetic flux in said magnetizable core that links said winding to produce an alternating polarity output voltage; a capacitance associated with said winding for aiding in the magnetic saturation of said saturable core section during each cycle of said alternating polarity output voltage to regulate said output voltage by ferroresonant operation; a load circuit within said television display system that is energized by said regulated alternating polarity output voltage; means for detecting a fault operating condition within said television display system; and means coupled to said detecting means and to said source of alternating input voltage and responsive to the detection of a fault operating condition for changing the operation of said source of alternating input voltage to one that results in said ferroresonant power supply being operated in a mode that is incapable of sustaining ferroresonance in order to disable operation of said television display system load circuit.

Claim 3

A system according to claim 1 wherein said exciting current developing means comprises a transformer having first, second and third windings, said second and third transformer windings being magnetically relatively tightly coupled to each other, said alternating input voltage source being coupled to said transformer first winding, said load circuit being coupled to said transformer third winding, said winding located on said magnetizable core being coupled to said transformer second winding for developing said regulated alternating polarity output voltage across said transformer second winding.

Claim 4

A system according to claim 2 wherein the amplitude of the voltage developed across said transformer second winding increases when said winding located on said magnetizable core is disconnected from said transformer second winding.

Claim 5

A system according to claim 3 wherein said load circuit includes an ultor terminal and a high voltage rectifying arrangement coupled to said transformer third winding for developing a DC ultor voltage at said ultor terminal.

Claim 6

A system according to claim 4 including a deflection winding, a deflection generator coupled thereto and energized by a B+ scanning voltage for developing scanning current in said deflection winding and means responsive to said regulating alternating polarity output voltage for developing therefrom said B+ scanning voltage.

Claim 8

A system according to claim 6 wherein said controllable source of alternating input voltage comprises a source of DC voltage, an oscillator including a control circuit and output switching means coupled to said source of DC voltage and having a control terminal coupled to said control circuit for developing said alternating input voltage from said DC voltage, the frequency of said alternating input voltage being determined by the frequency of operation of said oscillator.

Claim 9

A system according to claim 7 wherein said means for changing the frequency of operation of said source of alternating input voltage includes a reactive network and means for coupling said reactive network in circuit with said oscillator control circuit only in response to said fault signal to change the frequency of operation of said oscillator to one that results in the disruption of the operation of said ferroresonant power supply.

Claim 10

A system according to claim 8 wherein the frequency of operation of said oscillator during a fault operating condition is changed to one that is too high to sustain ferroresonant operation.

Claim 11

A system according to claim 9 wherein the frequency of operation of said oscillator during a fault operating condition is around 100 kilohertz or higher.

Claim 12

A system according to claim 8 including a horizontal deflection winding and a horizontal deflection generator coupled thereto for developing horizontal deflection current in said deflection winding, wherein said control circuit includes means coupled to said horizontal deflection generator for synchronizing operation of said oscillator with horizontal deflection.

Claim 13

A television display system that includes a ferroresonant power supply with a protection circuit for disabling normal operation of a load circuit within said television display system during a fault operating condition, comprising: a source of direct voltage; an oscillator including output switching means coupled to said direct voltage source for developing at an output of said oscillator an alternating supply voltage having a frequency that is related to the frequency of operation of said oscillator, said oscillator including first control means for producing oscillator operation at a first frequency; a magnetizable core including a saturable core section; a winding located on said core; means responsive to said alternating supply voltage for developing an exciting current that generates a magnetic flux in said magnetizable core that links said winding to produce an alternating polarity output voltage; a capacitance associated with said winding for aiding in the magnetic saturation of said saturable core section during each cycle of said alternating polarity output voltage to regulate said output voltage by ferroresonant operation; a load circuit within said television display system that is energized by said regulated alternating polarity output voltage; means for generating a fault detection signal during the occurrence of a fault operating condition within said television display system; and auxiliary control means coupled to said oscillator and activated by said fault detection signal for changing the frequency of operation of said oscillator to a second one that produces a disruption of the operation of said ferroresonant power supply by means of the inability of said power supply to remain in ferroresonance in order to disable operation of said television display system load circuit.

Claim 14

A television display system that includes a ferroresonant power supply with a protection circuit for disabling normal operation of a load circuit within said television display system during a fault operating condition, comprising: a source of direct voltage; an oscillator including output switching means coupled to said direct voltage source for developing at an output of said oscillator an alternating supply voltage having a frequency that is related to the frequency of operation of said oscillator, said oscillator including first control means for producing oscillator operation at a first frequency; a magnetizable core including a saturable core section; a winding located on said core; means responsive to said alternating supply voltage for developing an exciting current that generates a magnetic flux in said magnetizable core that links said winding to produce an alternating polarity output voltage; a capacitance associated with said winding for aiding in the magnetic saturation of said saturable core section during each cycle of said alternating polarity output voltage to regulate said output voltage by ferroresonant operation; a load circuit within said television display system that is energized by said regulated alternating polarity output voltage; means for generating a fault detection signal during the occurrence of a fault operating condition within said television display system; and auxiliary control means coupled to said oscillator and activated by said fault detection signal for changing the frequency of operation of said oscillator to a second one that produces a disruption of the operation of said ferroresonant power supply by means of the inability of said power supply to remain in ferroresonance in order to disable operation of said television display system load circuit.

Claim 15

A system according to claim 12 wherein said auxiliary control means includes a reactive network and means for coupling said reactive network in circuit with said first control means only in response to the generation of said fault detection signal.

Claim 16

A system according to claim 13 wherein said second frequency of oscillator operation is one that is too high to sustain ferroresonant operation.

Claim 17

A system according to claim 14 wherein said first control means includes means responsive to a horizontal deflection rate signal developed within said television display system for establishing said first frequency as the horizontal deflection frequency.

Claim 18

A system according to claim 15 wherein said second frequency of oscillator operation is around 100 kilohertz or higher.

Claim 20

A system according to claim 17 wherein said third frequency of oscillator operation is between 5 and 10 kilohertz.

Claim 21

A system according to claim 14 wherein said exciting current development means comprises a transformer having first, second and third windings, said second and third transformer windings being magnetically relatively tightly coupled to each other, said alternating supply voltage source being applied to said transformer first winding, said load circuit being coupled to said transformer third winding, said winding located on said magnetizable core being coupled to said transformer second winding for developing said regulated alternating polarity output voltage across said transformer second winding.

Claim 22

A system according to claim 19 wherein the amplitude of the voltage developed across said transformer second winding increases when said winding located on said magnetizable core is disconnected from said transformer second winding.

Claim 23

A system according to claim 20 wherein said fault detecting signal generating means includes another winding located on said magnetizable core, said fault detection signal being developed across said other winding only in the presence of a fault operating condition.

Claim 24

A system according to claim 20 wherein said load circuit includes an ultor terminal and a high voltage rectifying arrangement coupled to said transformer third winding for developing a DC ultor voltage at said ultor terminal.

Claim 25

A system according to claim 22 including a deflection winding, a deflection generator coupled thereto an energized by a B+ scanning voltage for developing scanning current in said deflection winding and means responsive to said regulating alternating polarity output voltage for developing therefrom said B+ scanning voltage.