Patent US3668435A successfully refreshed from Google Patents.
US3668435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved efficiency pulse forming network charging systems
Assignee: Raytheon Co
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Filing: 1970-08-12
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Granted: 1972-06-06
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Expires: 1990-08-12
Abstract
Abstract A current feedback switch for the charging supply of a pulse forming network (PFN) is provided with regenerative feedback through a transformer T2 and a control transistor Q2 in order that base current be more efficiently provided to drive a main switching transistor Q1 to saturation. Turning-off the main switching transistor Q1 is facilitated by the transistor Q2 in series with the feedback transformer T2. In that manner current is more efficiently turned on and off to charge the PFN.
Inventors
- 👤 Robert P Farnsworth
- 👤 Rodney J Dahlinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:27
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/53; H03K3/57; H03K17/00; H03K17/04; H03K17/042; H03K17/0424; H03K3/26; H03K3/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
278 words
Apparatus comprising: a source of power; a first junction transistor of a given conductivity type having a base, an emitter and a collector; a first transformer having its primary winding connected in series with said source of power and the collector of said first transistor; means for connecting the emitter of said first transistor to said source of power for conduction of current through the primary winding of said first transformer, and the collector and emitter of said first transistor when current is applied to the base of said first transistor to forward bias a junction between the base and emitter of said first transistor; a second junction transistor of the same conductivity type as said first transistor and having a base, an emitter and a collector; means for directly connecting the emitter of said second transistor to the base of said first transistor; means for selectively applying current to the base of said second transistor to forward bias a junction between the base and emitter of said second transistor; and a regenerative feedback transformer having its primary winding in series with the primary winding of said first transformer and the collector of said first transistor and having its secondary winding connected between the collector of said first transistor and the collector of said second transistor, thereby increasing the bias potential of said second transistor between the collector and emitter thereof when said first transistor conducts current through the primary winding of said regenerative transformer, thus allowing the first transistor to saturate and said second transistor to provide drive current through the base of said first transistor in relation to the collector current conducted by said first transistor.
Claim 2
Dependent Claim
278 words
Apparatus comprising: a source of power; a first junction transistor of a given conductivity type having a base, an emitter and a collector; a first transformer having its primary winding connected in series with said source of power and the collector of said first transistor; means for connecting the emitter of said first transistor to said source of power for conduction of current through the primary winding of said first transformer, and the collector and emitter of said first transistor when current is applied to the base of said first transistor to forward bias a junction between the base and emitter of said first transistor; a second junction transistor of the same conductivity type as said first transistor and having a base, an emitter and a collector; means for directly connecting the emitter of said second transistor to the base of said first transistor; means for selectively applying current to the base of said second transistor to forward bias a junction between the base and emitter of said second transistor; and a regenerative feedback transformer having its primary winding in series with the primary winding of said first transformer and the collector of said first transistor and having its secondary winding connected between the collector of said first transistor and the collector of said second transistor, thereby increasing the bias potential of said second transistor between the collector and emitter thereof when said first transistor conducts current through the primary winding of said regenerative transformer, thus allowing the first transistor to saturate and said second transistor to provide drive current through the base of said first transistor in relation to the collector current conducted by said first transistor.
Claim 3
Dependent Claim
15 words
Apparatus as defined in claim 1 wherein said regenerative feedback transformer is a non-saturating transformer.
Claim 4
Dependent Claim
136 words
A transistor switching circuit comprising first and second transistors of the same conductivity type, each having a base, an emitter and a collector, a transformer having a primary winding and a secondary winding, said first transistor having its emitter connnected to circuit ground and its collector connected in series with a source of power through said primary winding, and said second transistor having its emitter connected directly to said base of said first transistor and its collector connected to said collector of said first transistor through said secondary winding, the sense of said seconary winding being selected to provide regenerative feedback of drive current through said collector and emitter of said second transistor, and means for controlling drive current to said base of said second transistor for switching said first transistor on to saturation and off.
Claim 5
Dependent Claim
136 words
A transistor switching circuit comprising first and second transistors of the same conductivity type, each having a base, an emitter and a collector, a transformer having a primary winding and a secondary winding, said first transistor having its emitter connnected to circuit ground and its collector connected in series with a source of power through said primary winding, and said second transistor having its emitter connected directly to said base of said first transistor and its collector connected to said collector of said first transistor through said secondary winding, the sense of said seconary winding being selected to provide regenerative feedback of drive current through said collector and emitter of said second transistor, and means for controlling drive current to said base of said second transistor for switching said first transistor on to saturation and off.
Claim 6
Dependent Claim
19 words
A transistor switching circuit as defined in claim 3 including a resistor connected between terminals of said secondary winding.
Claim 7
Dependent Claim
45 words
A transistor switching circuit as defined in claim 4 including a diode connected between said base and said emitter of said second transistor and poled for forward conduction when said second transistor is turned off by base drive current applied thereto of a particular polarity.
Claim 8
Dependent Claim
20 words
A transistor switching circuit as defined in claim 5 including a high powered load in series with said primary winding.
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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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |