High voltage protection circuitry

Claim 2

In a television receiver employing a display device utilizing high voltage and scanning voltages, high-voltage protection circuitry comprising in combination: signal generating means; control poteNtial developing and applying means coupled to said signal generating means to effect generation of signals within a given range of frequencies for proper scanning of said display device; output potential means coupled to said signal generating means and intermediate a potential source and a potential reference level to effect development of said high voltage, high-voltage related, and scanning potentials for said display device; and signal frequency control means coupling said output potential means to said control potential developing and applying means to affect alteration in said signals developed by said signal generating means to frequencies outside said given range of frequencies in response to variations in magnitude of said high voltage whereby undesired variations in high-voltage magnitude are by alternations in signal frequency in an amount sufficient to alter scanning of the display device.

Claim 3

The combination of claim 1 wherein said signal frequency control means includes a voltage dependent resistor and a resistor series coupled intermediate said output potential means and a potential reference level with the junction of said series connected voltage dependent resistor and resistor coupled to said control potential developing and applying means.

Claim 4

The combination of claim 1 wherein said signal frequency control means includes voltage dependent resistor and a resistor series coupled intermediate said output potential means and a potential reference level and a unidirectional conduction device coupling the junction of said series connected voltage dependent resistor and resistor to said control potential developing and applying means.

Claim 5

The combination of claim 1 wherein said signal frequency control means is coupled and responsive to a high-voltage related potential of said output potential means for effecting alteration of said control potential developing and applying means and of said signals generated by said signal generating means, said generated signals being outside said given range of frequencies causing alteration in scanning of said display device.

Claim 6

The combination of claim 1 wherein said given range of frequencies is within about 300 cycles of the scanning frequency of the television receiver.

Claim 7

The combination of claim 1 wherein said television receiver includes a synchronizing pulse signal source and said control potential developing and applying means is coupled to and derives a control potential from said synchronizing pulse signal source and said output potential means.

Claim 8

In a television receiver which includes a synchronizing pulse signal source and employs a cathode-ray tube utilizing high-voltage and scanning voltages, high-voltage protection circuitry comprising in combination: horizontal oscillator means; horizontal output means coupled to said oscillator means for developing high voltage and high-voltage related potentials and scanning potentials within a given range of frequencies; control potential developing and applying means coupled to said synchronizing pulse signal source and said horizontal output means to effect development of a control potential for controlling development of signals within said given range of frequencies by said horizontal oscillator means; and signal frequency control means coupling said horizontal output means to said control potential developing and applying means to effect development of signals outside said given range of frequencies by said horizontal oscillator means in response to variations in said high-voltage potential of said horizontal output means whereby an increase in high-voltage potential causes a shift in scanning potentials distorting the scan of the cathode-ray tube.

Claim 9

In a television receiver which includes a synchronizing pulse signal source and employs a cathode-ray tube utilizing high-voltage and scanning voltages, high-voltage protection circuitry comprising in combination: horizontal oscillator means; horizontal output means coupled to said oscillator means for developing high voltage and high-voltage related potentials and scanning potentials within a given range of frequencies; control potential developing and applying means coupled to said synchronizing pulse signal source and said horizontal output means to effect development of a control potential for controlling development of signals within said given range of frequencies by said horizontal oscillator means; and signal frequency control means coupling said horizontal output means to said control potential developing and applying means to effect development of signals outside said given range of frequencies by said horizontal oscillator means in response to variations in said high-voltage potential of said horizontal output means whereby an increase in high-voltage potential causes a shift in scanning potentials distorting the scan of the cathode-ray tube.

Claim 10

The combination of claim 7 wherein said horizontal output means includes a high-voltage related potential source and said signal frequency control means includes a voltage dependent resistor and a resistor series coupling said source to a potential reference level And the junction of said voltage dependent resistor and resistor coupled to said control potential developing and applying means

Claim 11

The combination of claim 8 including a unidirectional conduction device coupling said junction of said series connected voltage dependent resistor and resistor to said control potential developing and applying means.

Claim 12

The combination of claim 8 including a capacitor shunting said resistor.