US3603811A
Expired / Lapsed
US
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Two-terminal bipolar self-powered low current limiter
Assignee: American Optical Corp
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Filing: 1969-12-09
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Granted: 1971-09-07
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Expires: 1989-12-09
Abstract
Abstract A two-terminal, bipolar, self-powered low current limiter having particularly advantageous use for limiting currents in body electrodes connected to biomedical electronic equipment to the microampere range. In one embodiment of the invention, a pair of series connected field effect transistors form a bipolar current limiting device. In another embodiment of the invention, four field-effect transistors are provided in the form of two series connected bistable devices. In both cases, an additional pair of field-effect transistors can be used to increase the breakdown voltage in both directions.
Inventors
- 👤 Christopher C Day
- 👤 Bo Holte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:31
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/353; H03K3/356; H03K3/3565; H02; H02H; H02H9/00; H02H9/02; H02H9/025; Y; Y10; Y10S; Y10S128/00; Y10S128/908; Y10S323/00; Y10S323/911
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
74 words
A two-terminal, bipolar, self-powered current limiting device comprising first and second field-effect transistors, each having drain, source and gate terminals, input and output terminals, each of said drain terminals being coupled to a respective one of said input and output terminals, impedance means connected between the source terminals of said two transistors, and means for coupling the gate terminal of each of said transistors to the source terminal of the other of said transistors.
Claim 2
Dependent Claim
74 words
A two-terminal, bipolar, self-powered current limiting device comprising first and second field-effect transistors, each having drain, source and gate terminals, input and output terminals, each of said drain terminals being coupled to a respective one of said input and output terminals, impedance means connected between the source terminals of said two transistors, and means for coupling the gate terminal of each of said transistors to the source terminal of the other of said transistors.
Claim 3
Dependent Claim
23 words
A two-terminal, bipolar, self-powered current limiting device in accordance with claim 1 wherein an impedance is included in each of said coupling means.
Claim 4
Dependent Claim
94 words
A two-terminal, bipolar, self-powered current limiting device in accordance with claim 1 further including an additional pair of field-effect transistors, the drain of each of said first and second field-effect transistors being coupled to the source of a respective one of said additional field-effect transistors, the gate of each of said first and second field-effect transistors being connected directly to the gate of the respective one of said additional field-effect transistors, and the drain of each of said additional field-effect transistors being connected directly to a respective one of said input and output terminals.
Claim 5
Dependent Claim
30 words
A two-terminal, bipolar, self-powered current limiting device in accordance with claim 3 wherein each of said additional field-effect transistors has a higher pinch-off voltage than said first and second transistors.
Claim 6
Dependent Claim
23 words
A two-terminal, bipolar, self-powered current limiting device in accordance with claim 4 wherein an impedance is included in each of said coupling means.
Claim 7
Dependent Claim
23 words
A two-terminal, bipolar, self-powered current limiting device in accordance with claim 3 wherein an impedance is included in each of said coupling means.
Claim 8
Dependent Claim
160 words
A two-terminal, bipolar, bistable, self-powered current limiting device comprising a pair of input terminals and a pair of active circuits; each of said active circuits including first and second field-effect transistors of one type and a third field-effect transistor of the opposite type, the gates of said first and second transistors being connected to each other, the source of said second transistor and the source of said third transistor being connected together, the gate of said third transistor, the drain of said second transistor and the source of said first transistor being connected together, and the drain of said first transistor being connected to a respective one of said pair of input terminals; means for connecting the drains of the third transistors in said two active circuits; and means for connecting the intercoNnected gates of the first and second transistors in each of said active circuits to the drain of the third transistor in the other of said active circuits.
Claim 9
Dependent Claim
160 words
A two-terminal, bipolar, bistable, self-powered current limiting device comprising a pair of input terminals and a pair of active circuits; each of said active circuits including first and second field-effect transistors of one type and a third field-effect transistor of the opposite type, the gates of said first and second transistors being connected to each other, the source of said second transistor and the source of said third transistor being connected together, the gate of said third transistor, the drain of said second transistor and the source of said first transistor being connected together, and the drain of said first transistor being connected to a respective one of said pair of input terminals; means for connecting the drains of the third transistors in said two active circuits; and means for connecting the intercoNnected gates of the first and second transistors in each of said active circuits to the drain of the third transistor in the other of said active circuits.
Claim 10
Dependent Claim
37 words
A two-terminal, bipolar, self-powered current limiting device in accordance with claim 7 wherein the first transistor in each of said active circuits has a higher pinch-off voltage than the second transistor in each of said active circuits.
References Cited (Backward Citations)
US3369129A
Cited
US3521087A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |