US3795767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High voltage protection circuit
Assignee: RCA Licensing Corp
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Filing: 1972-08-25
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Granted: 1974-03-05
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Expires: 1992-08-25
Abstract
Abstract A high voltage protection circuit for a television receiver for sensing increases in the kinescope ultor voltage above a predetermined level and for blanking the video signals applied to the kinescope during the time the ultor voltage exceeds the predetermined level. Automatic resetting of the video blanking circuit is accomplished during the television retrace intervals to restore displayed video when the ultor voltage drops below the predetermined level.
Inventors
- 👤 R Waltner
- 👤 M Norman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:10
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
147 words
A high voltage protection circuit for a television receiver, comprising: a source of voltage representative of variations in the ultor supply voltage of the picture tube of said receiver; switching means coupled to said source of voltage and responsive to said variations for switching from a first to a second state when said source voltage exceeds a predetermined voltage; a source of video signals; a video signal blanking circuit coupled to said source of video signals and to said switching means and responsive to said second state of said switching means for blanking said video signals, thereby causing blanking of said receiver kinescope display; a source of signals occurring during the retrace intervals of said television receiver; and means coupling said source of retrace interval signals to said switching means for resetting said switching means from said second state to said first state during said retrace interval.
Claim 2
Dependent Claim
147 words
A high voltage protection circuit for a television receiver, comprising: a source of voltage representative of variations in the ultor supply voltage of the picture tube of said receiver; switching means coupled to said source of voltage and responsive to said variations for switching from a first to a second state when said source voltage exceeds a predetermined voltage; a source of video signals; a video signal blanking circuit coupled to said source of video signals and to said switching means and responsive to said second state of said switching means for blanking said video signals, thereby causing blanking of said receiver kinescope display; a source of signals occurring during the retrace intervals of said television receiver; and means coupling said source of retrace interval signals to said switching means for resetting said switching means from said second state to said first state during said retrace interval.
Claim 3
Dependent Claim
32 words
A high voltage protection circuit according to claim 1 wherein said switching means is a neon light which acts as an effectively closed switch when said source voltage exceeds said predetermined voltage.
Claim 4
Dependent Claim
139 words
A high voltage protection circuit for a television receiver, comprising: a source of voltage representative of variations in the ultor supply voltage of the picture tube of said receiver; a neon light coupled to saiD source and responsive to said variations for switching from a first to a second state when said source voltage exceeds a predetermined voltage; a source of video signals; video signal blanking means coupled to said source of video signals and to said neon light and responsive to said second state of said neon light for blanking said video signals; a source of signals occurring during the vertical retrace intervals of said television receiver; and, means coupling said source of vertical retrace interval signals to said neon light for switching said neon light from said second to said first state during said vertical retrace interval.
Claim 5
Dependent Claim
139 words
A high voltage protection circuit for a television receiver, comprising: a source of voltage representative of variations in the ultor supply voltage of the picture tube of said receiver; a neon light coupled to saiD source and responsive to said variations for switching from a first to a second state when said source voltage exceeds a predetermined voltage; a source of video signals; video signal blanking means coupled to said source of video signals and to said neon light and responsive to said second state of said neon light for blanking said video signals; a source of signals occurring during the vertical retrace intervals of said television receiver; and, means coupling said source of vertical retrace interval signals to said neon light for switching said neon light from said second to said first state during said vertical retrace interval.
Claim 6
Dependent Claim
72 words
A high voltage protection circuit according to claim 3 wherein said resetting means include a diode poled to couple the peaks of said vertical retrace pulses to the terminal of said neon light remote from said source of voltage representative of variations in the ultor supply voltage for reducing the voltage across said light below said predetermined voltage for causing said light to extinguish and thereby act as an effectively open switch.
References Cited (Backward Citations)
US3692933A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |