US3789260A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High voltage protection circuit
Assignee: RCA Licensing Corp
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Filing: 1973-03-23
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Granted: 1974-01-29
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Expires: 1993-03-23
Abstract
Abstract Loss of high voltage regulation in a television receiver can cause an increase in the ultor voltage developed for its picture tube and an increase in the possibility of X-radiation. The described circuit senses the loss of such regulation by detecting high voltage increases beyond a predetermined value and by changing the frequency of the horizontal oscillator, in response, to render the reproduced picture unviewable.
Inventors
- 👤 P Ahrens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:43
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/18; H04N3/185; H04N3/1856
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
228 words
In a television receiver having an image display device, a deflection circuit including an oscillation signal generator and an S-shaping capacitor, and a high voltage circuit including a flyback transformer and a return capacitor therefor responsive to the generation of such oscillation signals to develop the high voltage needed to operate said display device, the combination therewith of: regulator means coupled to monitor a direct voltage developed across one of said S-shaping and flyback transformer return capacitors as an indicant of said high voltage and to respond to variations in the development thereof to stabilize said high voltage within a given range of operation; and control means also coupled to monitor a direct voltage developed across one of said S-shaping and flyback transformer return capacitors as an indicant of said high voltage and to respond to variations in the development thereof, but to apply a control signal to said oscillation generator substantially only in response to variations in its monitored indicant which arise when said regulator means becomes inoperative to permit said developed high voltage to exceed the upper limit of its stabilized range, said control signal being effective to change the frequency of said oscillation generator in a direction to render the image reproduction of said display device unviewable and to thereby provide a protective alert as to the existence of high voltage problems within said receiver.
Claim 2
Dependent Claim
228 words
In a television receiver having an image display device, a deflection circuit including an oscillation signal generator and an S-shaping capacitor, and a high voltage circuit including a flyback transformer and a return capacitor therefor responsive to the generation of such oscillation signals to develop the high voltage needed to operate said display device, the combination therewith of: regulator means coupled to monitor a direct voltage developed across one of said S-shaping and flyback transformer return capacitors as an indicant of said high voltage and to respond to variations in the development thereof to stabilize said high voltage within a given range of operation; and control means also coupled to monitor a direct voltage developed across one of said S-shaping and flyback transformer return capacitors as an indicant of said high voltage and to respond to variations in the development thereof, but to apply a control signal to said oscillation generator substantially only in response to variations in its monitored indicant which arise when said regulator means becomes inoperative to permit said developed high voltage to exceed the upper limit of its stabilized range, said control signal being effective to change the frequency of said oscillation generator in a direction to render the image reproduction of said display device unviewable and to thereby provide a protective alert as to the existence of high voltage problems within said receiver.
Claim 3
Dependent Claim
83 words
The combination of claim 1 wherein said control means includes a transistor in a first state of conduction for conditions of its monitored indicant which reflect the development of high voltages within said stabilized range of operation but rendered to a second state of conduction for applying said control signal to said oscillation generator in response to variations in its monitored indicant which reflect an inoperative regulator means permitting the development of high voltages in excess of the upper limit of said range.
Claim 4
Dependent Claim
77 words
The combination of claim 2 wherein said regulator means includes a transistor in a first state of conduction for conditions of its monitored indicant which reflect the development of high voltages within said stabilized range of operation but rendered to a second state of conduction for applying control signals to said deflection circuit in response to variations in its monitored indicant which reflect the development of high voltages in excess of the upper limit of said range.
Claim 5
Dependent Claim
34 words
The combination of claim 3 wherein said regulator transistor and said control transistor each monitor the direct voltage developed across the S-shaping capacitor of said deflection circuit as indicative of the high voltage generated.
Claim 6
Dependent Claim
45 words
The combInation of claim 3 wherein said regulator transistor monitors the direct voltage developed across said S-shaping capacitor and wherein said control transistor monitors the direct voltage developed across said flyback transformer return capacitor as indicative of the high voltages developed within said television receiver.
Claim 7
Dependent Claim
37 words
The combination of claim 3 wherein said regulator transistor and said control transistor each monitor the direct voltage developed across the flyback transformer return capacitor of said high voltage circuit as indicative of the high voltage generated.
Claim 8
Dependent Claim
45 words
The combination of claim 3 wherein said regulator transistor monitors the direct voltage developed across said flyback transformer return capacitor and wherein said control transistor monitors the direct voltage developed across said S-shaping capacitor as indicative of the high voltages developed within said television receiver.
References Cited (Backward Citations)
US3629644A
Cited
US3611002A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |