High-voltage regulation and protection circuit

Claim 2

In a cathode-ray tube system having a high-voltage source and a cathode-ray tube with a high-voltage electrode coupled to the high-voltage source, high-voltage regulation and protection circuitry comprising in combination: current generating means including an electron device having a first control electrode, a second control electrode, and an output electrode and a load circuit coupling the output electrode to said high voltage source; feedback bias means coupling said load circuit to said first control electrode of said electron device to effect variations in bias potential applied to said electron device in accordance with variations in potential of said load circuit; an AC source providing a potential available upon the availability of a potential from said high-voltage source; and switching means coupled to a junction intermediate said feedback bias means and said AC source and said second control electrode of said electron device whereby failure of a component of said feedback bias means causes activation of said switching means effecting a reduction in potential applied to said second control electrode and said load circuit.

Claim 3

The combination of claim 1 wherein said feedback bias means includes a capacitor coupling said load circuit to said first control electrode of said electron device and a voltage dependent resistor coupling the junction of said capacitor and first control electrode to a potential reference level.

Claim 4

The combination of claim 1 wherein said feedback bias means includes a capacitor and a second switching means series connected intermediate said load circuit and said first control electrode of said electron device and a voltage dependent resistor coupling the junction of said series connected capacitor and second switching means to a potEntial reference level.

Claim 5

The combination of claim 1 wherein said switching means is in the form of a silicon control rectified (SCR) having a gate electrode coupled to said junction intermediate said feedback bias means and said AC source.

Claim 6

The combination of claim 1 wherein said switching means is in the form of a silicon control rectified (SCR) having an anode electrode coupled to a DC potential source and to said second control electrode of said electron device, a cathode electrode coupled to a potential reference level, and a gate electrode coupled to a junction intermediate said feedback bias means and said AC source.

Claim 7

The combination of claim 1 wherein said current-generating means includes a bias-setting means in the form of an adjustable resistor coupled intermediate a potential source and a potential reference level and to said first control electrode of said electron device.

Claim 8

In a television receiver having a cathode-ray tube coupled to a high-voltage source, high-voltage regulation and protection circuitry comprising in combination: a horizontal output stage including a load circuit and an electron device having a first control electrode coupled to a bias means and to a signal source, a second control electrode coupled to a potential source, and an output electrode coupled to said load circuit, said load circuit being coupled to said high voltage source: feedback bias means including a capacitor coupling said load circuit to said first control electrode of said electron device and a voltage dependent resistor coupling the junction of said capacitor and first control electrode to a potential reference level: an AC source providing a potential available upon availability of a potential from said high voltage source: and protection switching means including a switching means connected intermediate a potential source and a potential reference level and coupled to said second control electrode of said electron device and to a junction intermediate said feedback bias means and an AC source whereby said feedback bias means controls the operation of said horizontal output stage and said high-voltage source and said protection switching means responds to component failure of said feedback bias means to reduce the potential from said high-voltage source.

Claim 9

In a television receiver having a cathode-ray tube coupled to a high-voltage source, high-voltage regulation and protection circuitry comprising in combination: a horizontal output stage including a load circuit and an electron device having a first control electrode coupled to a bias means and to a signal source, a second control electrode coupled to a potential source, and an output electrode coupled to said load circuit, said load circuit being coupled to said high voltage source: feedback bias means including a capacitor coupling said load circuit to said first control electrode of said electron device and a voltage dependent resistor coupling the junction of said capacitor and first control electrode to a potential reference level: an AC source providing a potential available upon availability of a potential from said high voltage source: and protection switching means including a switching means connected intermediate a potential source and a potential reference level and coupled to said second control electrode of said electron device and to a junction intermediate said feedback bias means and an AC source whereby said feedback bias means controls the operation of said horizontal output stage and said high-voltage source and said protection switching means responds to component failure of said feedback bias means to reduce the potential from said high-voltage source.

Claim 10

The combination of claim 7 wherein said load circuit is in the form of a horizontal output transformer coupled to a high-voltage source in the form of a voltage multiplier circuit and said feedback bias means includes a capacitor, diode, and impedance series connected intermediate said load circuit and said first control electrode of said electron device and a voltage dependent resistor coupling the junction of said capacitor and diode to a potential reference level.

Claim 11

The combination of claim 7 wherein said feedback bias means includes an impedance in the form of an adjustable resistor connected intermediate a potential source and a potential reference level with alterable arm coupled to said first control electrode of said electron device and by a diode to said capacitor.