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US3906304A Expired / Lapsed US ⏱️ 0.0 years remaining

High voltage protection circuit

Assignee: RCA Licensing Corp
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Filing: 1974-01-31
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Granted: 1975-09-16
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Expires: 1994-01-31
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Abstract

Abstract A horizontal deflection system driven auxiliary supply for a television receiver has as a rectifying device an integrated thyristor-rectifier (ITR). When the deflection system is operating under normal conditions, the rectifier portion of the ITR provides direct operating current through conventional filter circuitry to other receiver circuits, such as the vertical deflection system, whose performance is essential to the production of a viewable display. When the horizontal deflection system generates excessive voltage which results in an undesirable increase in the picture tube anode voltage derived from the deflection system, the peak cathode voltage of the rectifier portion, and thus the peak anode voltage of the thyristor portion of the ITR, rises. When the anode of the thyristor goes sufficiently positive with respect to its cathode, the voltage drop across the thyristor exceeds its breakover voltage and the thyristor begins to conduct heavily, removing the operating current from the other receiver circuits and rendering the display unviewable.

Inventors

  • 👤 Donald Henry Willis

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 09:22
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/20

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 161 words
A high voltage protection system for rendering a display on a kinescope unviewable when the high voltage coupled to said kinescope exceeds a predetermined level, comprising: a deflection system including a deflection winding, said deflection system being responsive to applied synchronizing waveforms for generating deflection current in said deflection winding; means for producing a viewable display; and voltage generating means coupled to said deflection system and to said means for producing a viewable display for generating operating voltage for said means for producing a viewable display, said voltage generating means including rectifying and switching means comprising an integrated thyristor-rectifier, a rectifier portion of which is coupled for rectifying alternating current voltage signals and for providing said operating voltage to said means for generating a viewable display and a thyristor portion of which switches into a state of conduction when said generated and rectified voltage across said integrated thyristor-rectifier exceeds said predetermined value for impairing said rectification thereby rendering said display unviewable.
Claim 2
Dependent Claim 161 words
A high voltage protection system for rendering a display on a kinescope unviewable when the high voltage coupled to said kinescope exceeds a predetermined level, comprising: a deflection system including a deflection winding, said deflection system being responsive to applied synchronizing waveforms for generating deflection current in said deflection winding; means for producing a viewable display; and voltage generating means coupled to said deflection system and to said means for producing a viewable display for generating operating voltage for said means for producing a viewable display, said voltage generating means including rectifying and switching means comprising an integrated thyristor-rectifier, a rectifier portion of which is coupled for rectifying alternating current voltage signals and for providing said operating voltage to said means for generating a viewable display and a thyristor portion of which switches into a state of conduction when said generated and rectified voltage across said integrated thyristor-rectifier exceeds said predetermined value for impairing said rectification thereby rendering said display unviewable.
Claim 3
Dependent Claim 151 words
A high voltage protection system for rendeRing a display on a kinescope unviewable when the high voltage coupled to said kinescope exceeds a predetermined level, comprising: a deflection winding; a deflection system coupled to said deflection winding for generating deflection current therein; means for producing a viewable display on said kinescope; means coupled to said deflection system for generating voltage variations in response to current flow in said deflection system; and rectifying and switching means comprising an integrated thyristor-rectifier having at least first and second states, said rectifier portion coupled for rectifying said generated voltage and supplying said rectified voltage to said means for producing a viewable display in said first state, and said thyristor portion coupled for decreasing said rectified voltage in said second state by forward conduction of said thyristor portion when said rectified voltage exceeds said generated voltage variations by said predetermined value for rendering said display unviewable.
Claim 4
Dependent Claim 151 words
A high voltage protection system for rendeRing a display on a kinescope unviewable when the high voltage coupled to said kinescope exceeds a predetermined level, comprising: a deflection winding; a deflection system coupled to said deflection winding for generating deflection current therein; means for producing a viewable display on said kinescope; means coupled to said deflection system for generating voltage variations in response to current flow in said deflection system; and rectifying and switching means comprising an integrated thyristor-rectifier having at least first and second states, said rectifier portion coupled for rectifying said generated voltage and supplying said rectified voltage to said means for producing a viewable display in said first state, and said thyristor portion coupled for decreasing said rectified voltage in said second state by forward conduction of said thyristor portion when said rectified voltage exceeds said generated voltage variations by said predetermined value for rendering said display unviewable.
Claim 5
Dependent Claim 146 words
A high voltage protection system for rendering a display on a kinescope unviewable when the high voltage coupled to said kinescope exceeds a predetermined level, comprising: deflection means for generating deflection current in a deflection winding; means for producing a viewable display on said kinescope; means coupled to said deflection means for generating an alternating current voltage in response to said flow of current in said deflection means; and bidirectional conductive switching means comprising an integrated thyristor-rectifier coupled to said voltage generating means and to said means for producing a viewable display, a rectifier portion of which is coupled for rectifying said generated voltage and for supplying said rectified voltage to said means for producing a viewable display, said thyristor portion being coupled for switching into forward conduction to substantially inhibit said rectification when the forward voltage across said thyristor portion exceeds its forward breakover voltage.
Claim 6
Dependent Claim 146 words
A high voltage protection system for rendering a display on a kinescope unviewable when the high voltage coupled to said kinescope exceeds a predetermined level, comprising: deflection means for generating deflection current in a deflection winding; means for producing a viewable display on said kinescope; means coupled to said deflection means for generating an alternating current voltage in response to said flow of current in said deflection means; and bidirectional conductive switching means comprising an integrated thyristor-rectifier coupled to said voltage generating means and to said means for producing a viewable display, a rectifier portion of which is coupled for rectifying said generated voltage and for supplying said rectified voltage to said means for producing a viewable display, said thyristor portion being coupled for switching into forward conduction to substantially inhibit said rectification when the forward voltage across said thyristor portion exceeds its forward breakover voltage.

References Cited (Backward Citations)

US3629644A Cited
US3767963A Cited
US3742242A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-09-15 1979-03-17 1979-09-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-09-15 1983-03-17 1983-09-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-09-15 1987-03-17 1987-09-16 $7700.00 Window Closed / Lapsed

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