US3784871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for generating a sawtooth current through a deflection coil
Assignee: US Philips Corp
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Filing: 1972-04-13
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Granted: 1974-01-08
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Expires: 1992-04-13
Abstract
Abstract A circuit arrangement for generating a sawtooth current through a deflection coil including two switches. The series network of an inductor and a capacitor is arranged between the two switches, while a second inductor is arranged between the supply source and a junction of one switch and the series network. The network constituted by the two inductors and the capacitor has a resonant frequency which is preferably between 0.5 and 0.8 times the repetition frequency of the sawtooth current (the line frequency) and the said switch is a unipolar switch (a thyristor).
Inventors
- 👤 P Vacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:28
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/83
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
163 words
A circuit for generating a sawtooth current having a selected repetition frequency for a deflection coil, said circuit comprising first and second switching means, means coupled to said second switching means for receiving and applying thereto a control signal having said selected repetition frequency, said second switching means comprising a unipolar switch, each of said switching means comprising first and second terminals; a series network comprising a first inductor and a first capacitor coupled between said first terminals; a second inductor having a first end coupled to said second switch first terminal and a second end adapted to receive a first lead of a voltage supply source; first means coupling said second terminals to a second lead of said source; second means for coupling said deflection coil to said first switch; said first and second inductors and said first capacitor comprising a resonant circuit having a resonant frequency lower than approximately said repetition and higher than approximately one half of said repetition frequency.
Claim 2
Dependent Claim
163 words
A circuit for generating a sawtooth current having a selected repetition frequency for a deflection coil, said circuit comprising first and second switching means, means coupled to said second switching means for receiving and applying thereto a control signal having said selected repetition frequency, said second switching means comprising a unipolar switch, each of said switching means comprising first and second terminals; a series network comprising a first inductor and a first capacitor coupled between said first terminals; a second inductor having a first end coupled to said second switch first terminal and a second end adapted to receive a first lead of a voltage supply source; first means coupling said second terminals to a second lead of said source; second means for coupling said deflection coil to said first switch; said first and second inductors and said first capacitor comprising a resonant circuit having a resonant frequency lower than approximately said repetition and higher than approximately one half of said repetition frequency.
Claim 3
Dependent Claim
21 words
A circuit as claimed in claim 1 wherein said resonant frequency is approximately between 0.5 and 0.8 times said repetition frequency.
Claim 4
Dependent Claim
20 words
A circuit as claimed in claim 2 wherein said resonant frequency is substantially equal to 0.6 times said repetition frequency.
Claim 5
Dependent Claim
55 words
A circuit as claimed in claim 1 wherein said second coupling means comprises a transformer having a secondary adapted to be coupled to said deflection coil, and a primary; a second capacitor series coupled to said primary; and a third capacitor parallel coupled to said second switch and to said second capacitor and said primary.
Claim 6
Dependent Claim
14 words
A circuit as claimed in claim 1 wherein said second switch comprises a thyristor.
Claim 7
Dependent Claim
22 words
A circuit as claimed in claim 1 wherein said first switch comprises a transistor having a large forward current capacity base-emitter path.
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) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |