Patent US3663944A successfully refreshed from Google Patents.
US3663944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inverter oscillator with voltage feedback
Assignee: National Aeronautics and Space Administration
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Filing: 1971-03-29
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Granted: 1972-05-16
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Expires: 1991-03-29
Abstract
Abstract An oscillator is disclosed for use in an inverter for a wide range of load using two transistors connected in a push-pull amplifier configuration having current feedback through primary windings of a saturable transformer connected in series with an output transformer between collectors of the transistors. Voltage feedback is provided through a third primary winding of the saturable transformer connected in series with a resistor between the collector of one transistor and a center tap in the primary winding of the output transformer.
Inventors
- 👤 Kurt Willner
- 👤 William T Mclyman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:14
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3382; H02M3/3384; H02M1/00; H02M1/0003; H02M1/0032; Y; Y02; Y02B; Y02B70/00; Y02B70/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
285 words
An oscillator of the push-pull amplifier type comprising first and second transistors each having a base, an emitter, and a collector, means connecting said emitters of said transistors to circuit ground, an output transformer having a center tapped primary winding with first and second terminals at extreme ends thereof, means for connecting said center tap of said output transformer to a source of DC voltage, a saturable transformer having a center tapped secondary winding with first and second terminals at extreme ends thereof, and first, second and third primary windings, said first and second primary windings having an equal number of turns, separate means for connecting the bases of said first and second transistors to respective ones of said first and second end terminals of said secondary winding of said saturable transformer, means for connecting said first primary winding of said saturable transformer between said first terminal of said primary winding of said output transformer and said collector of said first transistor with the polarity of said first primary winding selected to provide positive feedback current in the base of said first transistor when said first transistor conducts, means for connecting said second primary winding of said saturable transformer between said second terminal of said primary winding of said output transformer to said collector of said second transistor with the polarity of said second primary selected to pRovide positive feedback current in the base of said second transistor when said second transistor conducts, means for connecting said center tap of said secondary winding of said saturable transformer to circuit ground, and means for connecting said third primary of said saturable transformer between said source of dc voltage and said collector of one of said transistors.
Claim 2
Dependent Claim
285 words
An oscillator of the push-pull amplifier type comprising first and second transistors each having a base, an emitter, and a collector, means connecting said emitters of said transistors to circuit ground, an output transformer having a center tapped primary winding with first and second terminals at extreme ends thereof, means for connecting said center tap of said output transformer to a source of DC voltage, a saturable transformer having a center tapped secondary winding with first and second terminals at extreme ends thereof, and first, second and third primary windings, said first and second primary windings having an equal number of turns, separate means for connecting the bases of said first and second transistors to respective ones of said first and second end terminals of said secondary winding of said saturable transformer, means for connecting said first primary winding of said saturable transformer between said first terminal of said primary winding of said output transformer and said collector of said first transistor with the polarity of said first primary winding selected to provide positive feedback current in the base of said first transistor when said first transistor conducts, means for connecting said second primary winding of said saturable transformer between said second terminal of said primary winding of said output transformer to said collector of said second transistor with the polarity of said second primary selected to pRovide positive feedback current in the base of said second transistor when said second transistor conducts, means for connecting said center tap of said secondary winding of said saturable transformer to circuit ground, and means for connecting said third primary of said saturable transformer between said source of dc voltage and said collector of one of said transistors.
Claim 3
Dependent Claim
24 words
An oscillator as defined in claim 1 wherein said means for connecting said third primary winding between said source of dc voltage and said
Claim 4
Dependent Claim
18 words
An oscillator as defined in claim 2 including a capacitor connected in parallel with said current limiting resistor.
Claim 5
Dependent Claim
41 words
An oscillator as defined in claim 3 wherein said separate means for connecting said first and second terminals of said secondary winding of said saturable transformer to said bases of said first and second transistors each comprises a current limiting resistor.
Claim 6
Dependent Claim
315 words
An oscillator of the push-pull amplifier type comprising first and second transistors each having a base, an emitter and a collector, means for connecting said emitters of said transistors to circuit ground, an output transformer having a center tapped primary winding with first and second terminals at extreme ends thereof, means for connecting said center tap of said output transformer to a source of DC voltage, a saturable transformer having a center tapped secondary winding with first and second terminals at extremes ends thereof, and first and second primary windings, said first and second primary windings have an equal number of turns, separate means for connecting the bases of said first and second transistors to respective ones of said first and second end terminals of said secondary winding of said saturable transformer, means for connecting said first primary winding of said saturable transformer between said first terminal of said primary winding of said output transformer and said collector of said first transistor with the polarity of said first primary winding selected to provide positive feedback current in the base of said first transistor when said first transistor conducts, means for connecting said second primary of said saturable transformer winding between said second terminal of said primary winding of said output transformer to said collector of said second transistor with the polarity of said second primary selected to provide positive feedback current in the base of said second transistor when said second transistor conducts, a resistor connecting said center tap of said secondary winding of said saturable transformer to said source of DC voltage, a diode connecting said center tap of said secondary winding of said saturable transformer to said circuit ground, said diode being polled for forward conduction of base current in said transistors as they conduct alternately, a capacitor connected in parallel with said diode, and a third primary winding on said saturable transformer.
Claim 7
Dependent Claim
315 words
An oscillator of the push-pull amplifier type comprising first and second transistors each having a base, an emitter and a collector, means for connecting said emitters of said transistors to circuit ground, an output transformer having a center tapped primary winding with first and second terminals at extreme ends thereof, means for connecting said center tap of said output transformer to a source of DC voltage, a saturable transformer having a center tapped secondary winding with first and second terminals at extremes ends thereof, and first and second primary windings, said first and second primary windings have an equal number of turns, separate means for connecting the bases of said first and second transistors to respective ones of said first and second end terminals of said secondary winding of said saturable transformer, means for connecting said first primary winding of said saturable transformer between said first terminal of said primary winding of said output transformer and said collector of said first transistor with the polarity of said first primary winding selected to provide positive feedback current in the base of said first transistor when said first transistor conducts, means for connecting said second primary of said saturable transformer winding between said second terminal of said primary winding of said output transformer to said collector of said second transistor with the polarity of said second primary selected to provide positive feedback current in the base of said second transistor when said second transistor conducts, a resistor connecting said center tap of said secondary winding of said saturable transformer to said source of DC voltage, a diode connecting said center tap of said secondary winding of said saturable transformer to said circuit ground, said diode being polled for forward conduction of base current in said transistors as they conduct alternately, a capacitor connected in parallel with said diode, and a third primary winding on said saturable transformer.
Claim 8
Dependent Claim
36 words
An oscillator as defined in claim 5 wherein said means for connecting said third primary winding between said source of DC voltage and said collector of said one of said transistors comprises a current limiting resistor.
Claim 9
Dependent Claim
18 words
An oscillator as defined in claim 6 including a capacitor connected in parallel with said current limiting resistor.
Claim 10
Dependent Claim
42 words
An oscillator as defined in claim 7 wherein each of said means for connecting first and second terminals of said secondary winding of said saturable transformer to said base of each of said first and second transistors comprises a current limiting resistor.
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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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |