Patent US3236056A successfully refreshed from Google Patents.
Patent US3947755A successfully refreshed from Google Patents.
US3947755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for stabilizing the operating voltage of a sweep circuit for a cathode-ray tube
Assignee: Deutsche Thomson OHG
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Filing: 1974-08-05
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Granted: 1976-03-30
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Expires: 1994-08-05
Abstract
Abstract A circuit for stabilizing the operating voltage across a winding of output transformer of a sweep circuit of a cathode ray tube, including a plurality of current flow paths presenting resistances which are electronically controllable and each connected between a source of operating voltage which may fluctuate in amplitude and a respective one of a plurality of taps connected along the length of the winding, and a system for varying the resistances of the paths in response to changes in the amplitude of the operating voltage in such a manner as to maintain the voltage across the entirety of the winding substantially constant. The circuit is able to utilize inexpensive components while reducing overall energy losses.
Inventors
- 👤 Otto Daute
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:45
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/18; H04N3/185; G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/577; G05F1/62
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
268 words
In a system for producing sweep voltages for deflecting the beam of a cathode-ray tube, which system includes an operating voltage source whose output voltage is subject to amplitude variations, an output transformer having a winding, with one end of the winding being normally connected to the voltage source, a capacitor connecting the one end of the winding to a point of common potential for the system, a plurality of voltage-applying taps connected to the transformer at respectively different distances from the one end of the winding, and a circuit for connecting the operating voltage source to different ones of the taps, depending on the operating voltage amplitude, in order to stabilize the voltage across the transformer, the improvement wherein said circuit comprises: a plurality of electronically controllable variable resistance means each connected between said operating voltage source and a respective one of said taps; a plurality of diodes, each connected in series with a respective one of said variable resistance means and poled to be conductive in the direction of flow of the sweep voltage-producing operating current; and control means connected to control the conductive states of said variable resistance means, as a function of the amplitude of the operating voltage, in a manner such that upon the occurrence of successively lower operating voltage amplitude values, successive ones of said resistance means are rendered conductive in the order of the distance of their respective taps from said one end of said winding, starting from that one of said resistance means connected to that one of said taps which is closest to said one end of said winding.
Claim 2
Dependent Claim
268 words
In a system for producing sweep voltages for deflecting the beam of a cathode-ray tube, which system includes an operating voltage source whose output voltage is subject to amplitude variations, an output transformer having a winding, with one end of the winding being normally connected to the voltage source, a capacitor connecting the one end of the winding to a point of common potential for the system, a plurality of voltage-applying taps connected to the transformer at respectively different distances from the one end of the winding, and a circuit for connecting the operating voltage source to different ones of the taps, depending on the operating voltage amplitude, in order to stabilize the voltage across the transformer, the improvement wherein said circuit comprises: a plurality of electronically controllable variable resistance means each connected between said operating voltage source and a respective one of said taps; a plurality of diodes, each connected in series with a respective one of said variable resistance means and poled to be conductive in the direction of flow of the sweep voltage-producing operating current; and control means connected to control the conductive states of said variable resistance means, as a function of the amplitude of the operating voltage, in a manner such that upon the occurrence of successively lower operating voltage amplitude values, successive ones of said resistance means are rendered conductive in the order of the distance of their respective taps from said one end of said winding, starting from that one of said resistance means connected to that one of said taps which is closest to said one end of said winding.
Claim 3
Dependent Claim
60 words
An arrangement as defined in claim 1 wherein each said variable resistance means has one end connected to its associated tap via its respective diode and has its other end connected to the diode connected to the adjacent tap in the direction toward said one winding end, at the side of the latter diode directed away from its respective tap.
Claim 4
Dependent Claim
63 words
An arrangement as defined in claim 1 wherein each said resistance means after that one of said resistance means whose associated tap is nearest said one end of said winding is connected to receive as its control voltage the voltage drop across that one of said resistance means connected to the adjacent tap in the direction toward said one end of said winding.
Claim 5
Dependent Claim
40 words
An arrangement as defined in claim 1 comprising a further diode connected between the operating voltage source and said one end of said winding and poled to be conductive in the direction of flow of the sweep voltage-producing operating current.
Claim 6
Dependent Claim
35 words
An arrangement as defined in claim 1 wherein each said variable resistance means comprises a transistor whose variable resistance is present between its emitter and collector and whose base is connected to said control means.
Claim 7
Dependent Claim
77 words
An arrangement as defined in claim 5 wherein: said control means are connected to receive a reference voltage and a comparison voltage representative of that present at said one end of said winding; said control means has a control output connected to the base of that one of said transistors which is associated with the tap nearest said one end of said winding for rendering that transistor conductive when the operating voltage falls below a certain value.
Claim 8
Dependent Claim
70 words
An arrangement as defined in claim 6 wherein said control means comprises: a control transistor; a Zener diode connected to the emitter of said control transistor to provide the reference voltage; and a voltage divider having one end connected to said one end of said winding, with the base of said control transistor being connected to an intermediate point of said voltage divider, which intermediate point provides the comparison voltage.
Claim 9
Dependent Claim
87 words
An arrangement as defined in claim 5 wherein each said transistor other than the transistor whose associated tap is nearest said one end of said winding has its collector-emitter path connected between its associated tap and the point of connection between the tap adjacent its associated tap in the direction toward said one winding end and the transistor associated with said adjacent tap, and has its base connected to receive a control voltage corresponding to the collector-emitter voltage of the said transistor associated with said adjacent tap.
Claim 10
Dependent Claim
127 words
An arrangement as defined in claim 5 wherein said control means comprise a voltage divider having an intermediate point, the base of one said transistor which is associated with a tap other than the tap nearest said one end of said winding being connected to be controlled by the voltage at such intermediate point, the collector of said one of said transistors being connected to the adjacent tap in the direction toward said one winding end, the emitter of said one of said transistors being connected to its associated tap, and said voltage divider being connected between a point of the common potential for the system and the input of the transistor associated with the adjacent tap in the direction toward said one end of said winding.
Claim 11
Dependent Claim
53 words
An arrangement as defined in claim 9 wherein said control means further comprise an additional transistor having its base connected to said intermediate point of said voltage divider, its emitter connected to the collector of said one of said transistors, and its collector connected to the base of said one of said transistors.
Claim 12
Dependent Claim
37 words
An arrangement as defined in claim 10 comprising a protective diode connected between the base and the emitter of said additional transistor and poled in the direction opposite that of the base-emitter junction of said additional transistor.
Claim 13
Dependent Claim
31 words
An arrangement as defined in claim 1 further comprising a filter capacitor connected at the output side of at least one of said variable resistance means for suppressing switching voltage peaks.
Claim 14
Dependent Claim
20 words
An arrangement as defined in claim 1, further comprising an additional winding which winding is provided with said voltage-applying taps.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |