Patent US3885201A successfully refreshed from Google Patents.
US3885201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail-safe high voltage protection circuit
Assignee: RCA Licensing Corp
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Filing: 1974-05-28
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Granted: 1975-05-20
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Expires: 1994-05-28
Abstract
Abstract A fail-safe high voltage protection circuit for a television receiver includes means for rectifying pulses developed in the high voltage transformer for developing a direct current voltage proportional thereto for providing an additional bias voltage for the automatic frequency control (AFC) transistor. If the developed high voltage pulse becomes excessive, the corresponding increased bias supplied to the AFC transistor causes an increase in the horizontal oscillator frequency resulting in an unviewable raster.
Inventors
- 👤 Ronald Eugene Fernsler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:59
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
214 words
A high voltage protection circuit for rendering a display on a kinescope unviewable when excessive high voltage is coupled thereto, comprising: a deflection generator; high voltage supply means coupled to said deflection generator for generating said high voltage; means coupled to said deflection generator for producing voltage variations representative of said generated high voltage variations; power supply and regulating means coupled to said deflection generator and to said means for producing voltage variations and responsive to said voltage variations for regulating direct current operating voltage supplied to said deflection generator for maintaining said generated high voltage substantially constant; oscillator means coupled to said deflection generator; automatic frequency control means coupled to said deflection generator and to said oscillator for producing a first direct current control voltage for controlling the frequency of said oscillator; and means coupled to said means for producing voltage variations representative of said high voltage variations and to said automatic frequency control means for providing a second direct current control voltage thereto, said first and second control voltages being combined for controlling said oscillator at a desired frequency and said second direct current control voltage being related in amplitude to said voltage variations for rendering the display on said kinescope unviewable when said amplitude becomes excessive corresponding to excessive high voltage.
Claim 2
Dependent Claim
214 words
A high voltage protection circuit for rendering a display on a kinescope unviewable when excessive high voltage is coupled thereto, comprising: a deflection generator; high voltage supply means coupled to said deflection generator for generating said high voltage; means coupled to said deflection generator for producing voltage variations representative of said generated high voltage variations; power supply and regulating means coupled to said deflection generator and to said means for producing voltage variations and responsive to said voltage variations for regulating direct current operating voltage supplied to said deflection generator for maintaining said generated high voltage substantially constant; oscillator means coupled to said deflection generator; automatic frequency control means coupled to said deflection generator and to said oscillator for producing a first direct current control voltage for controlling the frequency of said oscillator; and means coupled to said means for producing voltage variations representative of said high voltage variations and to said automatic frequency control means for providing a second direct current control voltage thereto, said first and second control voltages being combined for controlling said oscillator at a desired frequency and said second direct current control voltage being related in amplitude to said voltage variations for rendering the display on said kinescope unviewable when said amplitude becomes excessive corresponding to excessive high voltage.
Claim 3
Dependent Claim
35 words
A high voltage protection circuit according to claim 1 wherein said means coupled to said deflection generator for producing voltage variations representative of said generated high voltage is a winding of a deflection output transformer.
Claim 4
Dependent Claim
43 words
A high voltage protection circuit according to claim 1 wherein a third direct current control voltage comprising an oscillator hold control voltage is coupled to said oscillator and automatic frequency control means in addition to said first and second direct current control voltages.
Claim 5
Dependent Claim
280 words
A high voltage protection circuit for rendering a diSplay on a kinescope unviewable when excessive high voltage is coupled thereto, comprising: a first control loop comprising: a horizontal deflection generator including switching means for generating deflection current in a deflection winding in response to control signals coupled thereto; high voltage generating means coupled to said deflection generator for generating high voltage for said kinescope in response to said switching; means coupled to said high voltage generating means for generating voltage variations representative of said generated high voltage; voltage supply and regulating means coupled to said deflection generator and to said means for generating voltage variations representative of said generated high voltage for supplying direct current operating potential to said deflection generator which varies in relation to said voltage variations representative of said generated high voltage for maintaining said generated high voltage substantially constant; and a second control loop comprising: said deflection generator; said high voltage supply means; said means for generating voltage variations representative of said generated high voltage; oscillator means coupled to said deflection generator; automatic frequency control means coupled to said deflection generator and to said oscillator for producing a first direct current control voltage for controlling the frequency of said oscillator; and means coupled to said means for generating voltage variations representative of said generated high voltage and to said automatic frequency control means for providing a second direct current control voltage thereto, said first and second control voltages being combined for controlling said oscillator at a desired frequency and said second direct current control voltage being related in amplitude to said variations for rendering the display on said kinescope unviewable when said high voltage becomes excessive.
Claim 6
Dependent Claim
280 words
A high voltage protection circuit for rendering a diSplay on a kinescope unviewable when excessive high voltage is coupled thereto, comprising: a first control loop comprising: a horizontal deflection generator including switching means for generating deflection current in a deflection winding in response to control signals coupled thereto; high voltage generating means coupled to said deflection generator for generating high voltage for said kinescope in response to said switching; means coupled to said high voltage generating means for generating voltage variations representative of said generated high voltage; voltage supply and regulating means coupled to said deflection generator and to said means for generating voltage variations representative of said generated high voltage for supplying direct current operating potential to said deflection generator which varies in relation to said voltage variations representative of said generated high voltage for maintaining said generated high voltage substantially constant; and a second control loop comprising: said deflection generator; said high voltage supply means; said means for generating voltage variations representative of said generated high voltage; oscillator means coupled to said deflection generator; automatic frequency control means coupled to said deflection generator and to said oscillator for producing a first direct current control voltage for controlling the frequency of said oscillator; and means coupled to said means for generating voltage variations representative of said generated high voltage and to said automatic frequency control means for providing a second direct current control voltage thereto, said first and second control voltages being combined for controlling said oscillator at a desired frequency and said second direct current control voltage being related in amplitude to said variations for rendering the display on said kinescope unviewable when said high voltage becomes excessive.
Claim 7
Dependent Claim
37 words
A high voltage protection circuit according to claim 4 wherein said means coupled to said high voltage generating means for generating voltage variations representative of said generated high voltage is a winding of a deflection output transformer.
Claim 8
Dependent Claim
43 words
A high voltage protection circuit according to claim 4 wherein a third direct current control voltage comprising an oscillator hold control voltage is coupled to said oscillator and automatic frequency control means in addition to said first and second direct current control voltages.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |