US3868538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferro-resonant high voltage system
Assignee: Zenith Electronics LLC
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Filing: 1973-05-11
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Granted: 1975-02-25
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Expires: 1993-05-11
Abstract
Abstract A cathode ray tube high-voltage supply system is of the type in which sawtooth-shaped pulses are developed in a first transformer winding in order to produce a scanning waveform in a deflection yoke on the tube. So-called fly-back energy, developed as a result of magnetic field collapse in the yoke during retrace, is utilized, in turn, to produce high-voltage output pulses in another winding to which a load is coupled that requires a broad, generally-square pulse shape. The first winding is wound upon a first ferromagnetic core that defines a non-saturating magnetic circuit. The other winding is wound upon a second ferromagnetic core which, together with a portion of the first core, defines a second magnetic circuit that saturates in operation. A capacitor included in the load is coupled across the other winding and controls the energy in said second magnetic circuit in such a manner as to supply the load with pulses that are broad and have a generally-square shape.
Inventors
- 👤 David L Blanchard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:24
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/10; H04N3/16; H04N3/18; H04N3/19; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/62
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
191 words
In a cathode ray tube high-voltage supply system in which sawtooth-shaped current pulses are developed in a first transformer winding in order to produce a scanning waveform in a deflection yoke on said cathode ray tube, in which energy developed as a result of magnetic field collapse in said deflection yoke is utilized to produce high-voltage output pulses in a second winding and in which the load coupled to said second winding requires a broad generally-square pulse shape, the improvement comprising: a first closed magnetic circuit non-saturating in response to development of said sawtooth-shaped pulses or in the presence of said energy and including a first ferromagnetic core upon which said first winding is wound; a second closed magnetic circuit saturating in response to said energy and including only a portion of said first core together with a second ferromagnetic core upon which said second winding is wound; and a capacitor, included in said load, coupled across said second winding and having a value enabling current cycles in said second winding to coincide with current cycles in said first winding sufficiently that said collapse initiates saturation reversal in said second core.
Claim 2
Dependent Claim
191 words
In a cathode ray tube high-voltage supply system in which sawtooth-shaped current pulses are developed in a first transformer winding in order to produce a scanning waveform in a deflection yoke on said cathode ray tube, in which energy developed as a result of magnetic field collapse in said deflection yoke is utilized to produce high-voltage output pulses in a second winding and in which the load coupled to said second winding requires a broad generally-square pulse shape, the improvement comprising: a first closed magnetic circuit non-saturating in response to development of said sawtooth-shaped pulses or in the presence of said energy and including a first ferromagnetic core upon which said first winding is wound; a second closed magnetic circuit saturating in response to said energy and including only a portion of said first core together with a second ferromagnetic core upon which said second winding is wound; and a capacitor, included in said load, coupled across said second winding and having a value enabling current cycles in said second winding to coincide with current cycles in said first winding sufficiently that said collapse initiates saturation reversal in said second core.
Claim 3
Dependent Claim
47 words
A system as defined in claim 1 in which said load includes a voltage multiplier having capacitance chargeable by said output pulses and in which the magnetization characteristic of said second core is selected to optimize charging of said capacitance after each appearance of said sawtooth-shaped pulses.
Claim 4
Dependent Claim
37 words
A system as defined in claim 1 in which said second core is proportioned magnetically to develop said output pulses for optimized application to said load while effecting minimal effect upon the shape of said sawtooth pulses.
Claim 5
Dependent Claim
48 words
A system as defined in claim 1 in which said capacitor is of a value to store energy from said output pulses in an amount sufficient to drive said second core into saturation during the return of energy from said capacitor in the intervals between said output pulses.
Claim 6
Dependent Claim
44 words
A system as defined in claim 1 in which the value of said capacitor and the magnetic characteristic of said second core are selected such that said second core exhibits one complete traversal of its hysteresis loop for each cycle of said sawtooth-shaped pulses.
Claim 7
Dependent Claim
47 words
A system as defined in claim 5 in which the amount of energy exchanged between said capacitor and said second core is sufficient to maintain the degree of peak saturation of said second core substantially the same both during said output pulses and in the interval therebetween.
Claim 8
Dependent Claim
59 words
A system as defined in claim 1 in which the magnetic reluctance of said portion is substantially smaller than that of the remainder of said first core, and the cross-sectional area of said portion is sufficiently large to prevent its saturation in response both to said developed energy and to energy exchange between said capacitor and said second core.
Claim 9
Dependent Claim
34 words
A system as defined in claim 1 in which said portion is unsaturated in response to energy in said system while said second core saturates in response to exchange of energy with said capacitor.
Claim 10
Dependent Claim
56 words
A system as defined in claim 1 in which the maximum coercive force existing in said first core is less than the coercive force of said second core at saturation flux density, and the maximum coercive force of said second core is greater than the coercive force of said first core at the saturation flux density.
Claim 11
Dependent Claim
46 words
A system as defined in claim 1 in which the value of said capacitor is sufficient to store energy from said output pulses in an amount ample to return to said second core energy equal to energy dissipated therein together with energy required by said load.
Claim 12
Dependent Claim
35 words
A system as defined in claim 1 in which said second core saturates at approximately the middle of the current cycle, following which saturation said capacitor discharges and then is charged in the reverse direction.
Claim 13
Dependent Claim
29 words
A system as defined in claim 1 in which said capacitor is alternately charged in opposing directions, and in which said second core alternately becomes saturated in reverse directions.
Claim 14
Dependent Claim
37 words
A system as defined in claim 1 in which said second winding exhibits a value of inductance, during unsaturation of said second case, sufficiently high to prevent any significant discharge of said capacitor into said second winding.
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) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |