US3898552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
DC Static switch circuit with improved transistor surge current pass capability
Assignee: Westinghouse Electric Corp
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Filing: 1974-02-21
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Granted: 1975-08-05
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Expires: 1994-02-21
Abstract
Abstract A DC static switch having a main switch transistor whose drive circuit includes a particular arrangement of complimentary polarity transistors connected so as to maintain low power dissipation while increasing the surge current pass capability of the main transistor.
Inventors
- 👤 Donal E Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:56
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/22; H; H03; H03K; H03K17/00; H03K17/06; H03K2217/00; H03K2217/0036
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
153 words
Static switch apparatus for controlling the application of DC power from a direct voltage source to a load and comprising: a first transistor of a first polarity having an emitter, a base, and a collector with a first terminal connected to said emitter for connection to the source of power and a second terminal connected to said collector for connection to the load; a second transistor of an opposite polarity to said first polarity having an emitter, a base, and a collector; said first transistor base and said second transistor collector being interconnected; said second transistor emitter being directly connected with said second terminal; a third transistor of said first polarity having an emitter, a base, and a collector; said second transistor collector and said thrid transistor emitter being interconnected; said second transistor base and said third transistor collector being interconnected; and said third transistor base having means for applying input signals thereto.
Claim 2
Dependent Claim
153 words
Static switch apparatus for controlling the application of DC power from a direct voltage source to a load and comprising: a first transistor of a first polarity having an emitter, a base, and a collector with a first terminal connected to said emitter for connection to the source of power and a second terminal connected to said collector for connection to the load; a second transistor of an opposite polarity to said first polarity having an emitter, a base, and a collector; said first transistor base and said second transistor collector being interconnected; said second transistor emitter being directly connected with said second terminal; a third transistor of said first polarity having an emitter, a base, and a collector; said second transistor collector and said thrid transistor emitter being interconnected; said second transistor base and said third transistor collector being interconnected; and said third transistor base having means for applying input signals thereto.
Claim 3
Dependent Claim
24 words
The subject matter of claim 1 wherein: said first and third transistors are of PNP polarity and said second transistor is of NPN polarity.
Claim 4
Dependent Claim
46 words
The subject matter of claim 1 wherein: the static switch apparatus is connected in circuit with a direct voltage source and a load and said direct voltage source is of a polarity to forward bias said first transistor emitter in relation to said first transistor base.
Claim 5
Dependent Claim
68 words
The subject matter of claim 1 further comprising: a fourth transistor of said opposite polarity having an emitter, a base, and a collector; said fourth transistor collector being interconnected through a resistor to said third transistor base; said fourth transistor emitter being connected to a reference potential, and said fourth transistor base being connected to a third terminal connected thereto for connection to a source of on/off signals.
References Cited (Backward Citations)
US3654518A
Cited
US3710231A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |