US3778639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor switch using a current sharing pulse transformer
Assignee: International Business Machines Corp
•
Filing: 1972-05-12
•
Granted: 1973-12-11
•
Expires: 1992-05-12
Abstract
Abstract The invention relates to a transistor switch circuit which employs the use of a current sharing pulse transformer. The current sharing pulse transformer has a secondary winding in the emitter circuit of each of the two transistors used within the circuit. Another secondary winding is connected to the bases of the two transistors used. Finally, another secondary winding is connected in the collector circuit of the transistor switch to provide a feedback signal. The current sharing pulse transformer is used to control the turn-on and turn-off of the transistor switch circuit. More specifically, the secondary windings in the emitter circuit controls the turn-off characteristic associated with the two transistors such that they will turn off at the same time.
Inventors
- 👤 Higuchi H Atsushi
- 👤 L Trubell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:54
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/12; H03K17/51; H03K17/56; H03K17/60; H03K17/601
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
120 words
A transistor switch circuit comprising: a first and second transistor; a current sharing pulse transformer having a primary winding and having a first secondary winding connected to the base of said transistors and having a second and third secondary winding connected to the emitter of each transistor for controlling the turn-off and turn-on of said transistors and for causing the turn-off characteristics of each of said transistors to be the same whereby both transistors turn-off at the same time, said current sharing pulse transformer further comprising a fourth secondary feedback winding connected to the collector of said transistors for causing said primary winding to supply only that energy necessary for providing the base current of said transistors within said circuit.
Claim 2
Dependent Claim
120 words
A transistor switch circuit comprising: a first and second transistor; a current sharing pulse transformer having a primary winding and having a first secondary winding connected to the base of said transistors and having a second and third secondary winding connected to the emitter of each transistor for controlling the turn-off and turn-on of said transistors and for causing the turn-off characteristics of each of said transistors to be the same whereby both transistors turn-off at the same time, said current sharing pulse transformer further comprising a fourth secondary feedback winding connected to the collector of said transistors for causing said primary winding to supply only that energy necessary for providing the base current of said transistors within said circuit.
Claim 3
Dependent Claim
153 words
A transistor switch circuit comprising: a first and second transistor; a current sharing pulse transformer having a primary winding and having a first secondary winding connected to the base of said transistors and having a second and third secondary winding connected to the emitter of each transistor for controlling the turn-on and turn-off of said transistors and for causing the turn-off characteristics of each of said transistors to be the same wHereby both transistors turn-off at the same time, wherein all said primary and secondary windings are wound on a closed magnetic core structure, said second and third secondary windings connected to said emitters being so placed on said core that a decrease or increase of current in one emitter winding will cause a corresponding decrease or increase of current in the other emitter winding for causing the emitters of said transistors to track each other and to turn-off at the same time.
Claim 4
Dependent Claim
153 words
A transistor switch circuit comprising: a first and second transistor; a current sharing pulse transformer having a primary winding and having a first secondary winding connected to the base of said transistors and having a second and third secondary winding connected to the emitter of each transistor for controlling the turn-on and turn-off of said transistors and for causing the turn-off characteristics of each of said transistors to be the same wHereby both transistors turn-off at the same time, wherein all said primary and secondary windings are wound on a closed magnetic core structure, said second and third secondary windings connected to said emitters being so placed on said core that a decrease or increase of current in one emitter winding will cause a corresponding decrease or increase of current in the other emitter winding for causing the emitters of said transistors to track each other and to turn-off at the same time.
Claim 5
Dependent Claim
79 words
A transistor switch circuit as set forth in claim 1 wherein all said primary and secondary windings are wound on a closed magnetic core structure, said second and third secondary windings being so placed on said core that a decrease or increase of current in one emitter winding will cause a corresponding decrease or increase of current in the other emitter winding for causing the emitters of said transistors to track each other and turn-off at the same time.
Claim 6
Dependent Claim
159 words
A transistor switch circuit comprising: a first and second transistor, each said transistor having a base, a collector and an emitter, said bases being directly connected together and said collectors being directly connected together; a current sharing transformer having a primary winding, a secondary base winding, a secondary first emitter winding, a secondary second emitter winding, and a secondary feedback winding, each of said windings having a positive and a negative terminal which defines the sense of said secondary windings to said primary windings; the positive terminal of said base winding being connected to said connected bases; the negative terminal of said first emitter winding being connected to the emitter of said first transistor; the negative terminal of said second emitter winding being connected to the emitter of said second transistor; the negative terminal of said feedback winding being connected to said connected collectors; and all said primary and secondary windings being wound on a closed magnetic core structure.
Claim 7
Dependent Claim
159 words
A transistor switch circuit comprising: a first and second transistor, each said transistor having a base, a collector and an emitter, said bases being directly connected together and said collectors being directly connected together; a current sharing transformer having a primary winding, a secondary base winding, a secondary first emitter winding, a secondary second emitter winding, and a secondary feedback winding, each of said windings having a positive and a negative terminal which defines the sense of said secondary windings to said primary windings; the positive terminal of said base winding being connected to said connected bases; the negative terminal of said first emitter winding being connected to the emitter of said first transistor; the negative terminal of said second emitter winding being connected to the emitter of said second transistor; the negative terminal of said feedback winding being connected to said connected collectors; and all said primary and secondary windings being wound on a closed magnetic core structure.
Claim 8
Dependent Claim
29 words
The transistor switch circuit as claimed in claim 4 further comprising a means in series of said feedback winding for providing an output signal from said transistor switch circuit.
Claim 9
Dependent Claim
29 words
The transistor switch circuit as claimed in claim 4 wherein said negative terminal of said base winding and said positive terminals of said emitter windings are connected to ground.
Claim 10
Dependent Claim
29 words
The transistor switch circuit as claimed in claim 5 wherein said negative terminal of said base winding and said positive terminals of said emitter windings are connected to ground.
Claim 11
Dependent Claim
75 words
A transistor switch circuit as set forth in claim 4 wherein said first and second emitter windings are so placed on said magnetic core structure that an increase or decrease in current in one of said emitter windings will cause a corresponding increase or decrease of current in the other emitter winding for causing the emitter circuits of said first and second transistors to track each other and to turn off at the same time.
Claim 12
Dependent Claim
29 words
The transistor circuit as set forth in claim 8 further comprising a means and series with said feedback winding for providing an output signal from said transistor switch circuit.
Claim 13
Dependent Claim
29 words
A transistor circuit as set forth in claim 8 wherein said negative terminals of said base winding and said positive terminals of said emitter windings are connected to ground.
Claim 14
Dependent Claim
30 words
The transistor switch circuit as set forth in claim 9 wherein said negative terminal of said base winding and said positive terminals of said emitter winding are connected to ground.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |