Patent US3689797A successfully refreshed from Google Patents.
US3689797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement in a picture display device utilizing a stabilized supply voltage circuit
Assignee: US Philips Corp
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Filing: 1970-04-13
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Granted: 1972-09-05
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Expires: 1990-04-13
Abstract
Abstract A stabilized supply voltage circuit for a picture display device comprising a chopper wherein the switching signal has the line frequency and is duration-modulated. The coil of the chopper constitutes the primary winding of a transformer a secondary winding of which drives the line output transistor so that the switching transistor of the chopper also functions as a driver for the line output stage. The oscillator generating the switching signal may be the line oscillator. In a special embodiment the driver and line output transistor conduct simultaneously and in order to limit the base current of the line output transistor a coil shunted by a diode is incorporated in the drive line of the line output transistor. Other secondary windings of the transformer drive diodes which conduct simultaneously with the efficiency diode of the chopper so as to generate further stabilized supply voltages.
Inventors
- 👤 Wilhelmus Theodor Hetterscheid
- 👤 Gerrit Pieter Johannes Schaik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:22
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/156; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/1213; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33507; H02M3/33523; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/62; H03K4/64; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/18; H04N3/185; H04N3/22; H04N3/23; H04N3/233
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
237 words
An electrical circuit arrangement for a picture display device operating at a given line scanning frequency, comprising a source of unidirectional voltage, an inductor, first switching transistor means for periodically energizing said inductor at said scanning frequency with current from said source, an electrical load circuit coupled to said inductor and having applied thereto a voltage as determined by the ratio of the ON and OFF periods of said transistor, means for maintaining the voltage across said load circuit at a given value comprising means for comparing the voltage of said load circuit with a reference voltage, means responsive to departures of the value of the load circuit voltage from the value of said reference voltage for varying the conduction ratio of the ON and OFF periods of said transistor thereby to stabilize said load circuit voltage at the given value, a line deflection coil system for said picture display device, means for energizing said line deflection coil system from said load voltage circuit means, means for periodically interrupting the energization of said line deflection coil comprising second switching means and means coupled to said inductor for deriving therefrom a switching current in synchronism with the energization periods of said transistor and applying said switching current to said switching means thereby to actuate the same, and means coupled to said switching means and to said load voltage circuit for producing a voltage for energizing said display device.
Claim 2
Dependent Claim
237 words
An electrical circuit arrangement for a picture display device operating at a given line scanning frequency, comprising a source of unidirectional voltage, an inductor, first switching transistor means for periodically energizing said inductor at said scanning frequency with current from said source, an electrical load circuit coupled to said inductor and having applied thereto a voltage as determined by the ratio of the ON and OFF periods of said transistor, means for maintaining the voltage across said load circuit at a given value comprising means for comparing the voltage of said load circuit with a reference voltage, means responsive to departures of the value of the load circuit voltage from the value of said reference voltage for varying the conduction ratio of the ON and OFF periods of said transistor thereby to stabilize said load circuit voltage at the given value, a line deflection coil system for said picture display device, means for energizing said line deflection coil system from said load voltage circuit means, means for periodically interrupting the energization of said line deflection coil comprising second switching means and means coupled to said inductor for deriving therefrom a switching current in synchronism with the energization periods of said transistor and applying said switching current to said switching means thereby to actuate the same, and means coupled to said switching means and to said load voltage circuit for producing a voltage for energizing said display device.
Claim 3
Dependent Claim
22 words
A circuit as claimed in claim 1 wherein the duty cycle of said switching transistor means is normally between 0.3 to 0.7.
Claim 4
Dependent Claim
17 words
A circuit as claimed in claim 1 further comprising an efficiency first diode coupled to said inductor.
Claim 5
Dependent Claim
33 words
A circuit as claimed in claim 3 further comprising at least a second diode coupled to said deriving means and to ground, and being poled to conduct simultaneously with said efficiency first diode.
Claim 6
Dependent Claim
64 words
A circuit as claimed in claim 1 wherein said second switching means comprises a second transistor coupled to said deriving means to conduct simultaneously with said first transistor, and further comprising a coil coupled between said driving means and said second transistor and a third diode shunt coupled to said coil and being poled to conduct when said first and second transistors are non-conducting.
Claim 7
Dependent Claim
27 words
A circuit as claimed in claim 1 further comprising a horizontal oscillator coupled to said first transistor, said oscillator being the horizontal oscillator of said display device.
Claim 8
Dependent Claim
22 words
A circuit as claimed in claim 1 further comprising means coupled to said inductor for deriving filament voltage for said display device.
References Cited (Backward Citations)
US3428856A
Cited
US3402318A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |