Patent US3619798A successfully refreshed from Google Patents.
US3619798A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-port electrical network
Assignee: University of Toronto Innovations Foundation
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Filing: 1969-11-20
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Granted: 1971-11-09
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Expires: 1989-11-20
Abstract
Abstract A three-port electrical network that has a first port whose impedance is high and whose voltage controls the potential of a second port which has low or zero impedance and through which an independent current flows to reappear at a third port at high impedance which consists of a unity gain amplifier having high input impedance and low output impedance and means for deriving a current related to the current flowing in the output port of the amplifier and means for conveying this current to a third port. The latter two means are current followers energized from constant current sources.
Inventors
- 👤 Kenneth C Smith
- 👤 Adel S Sedra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:30
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/561; H03F1/00; H03F1/56; H03F3/34; H03F3/343; H03H; H03H11/00; H03H11/02; H03H11/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
206 words
A three-port electrical network that has a first port whose impedance is high and whose voltage controls the potential of a second port exhibiting substantially zero impedance and through which an independent current flows to reappear at a third port where impedance is high comprising a unity gain transistorized amplifying stage whose control electrode is connected to the said first port of the network, whose output is connected to the said second port and also to a first source of constant biasing current and whose input is connected to a voltage bias source through an impedance, a current follower comprising a transistor whose output is connected to a second source of constant biasing current equal in magnitude to the biasing current form the first source, whose input is connected to the said voltage bias source through an impedance, and whose control electrode is connected to the input of the said amplifying stage such that the current follower provides at its output a current related in magnitude to the current flowing into the said second port, and means comprising a connection to said current follower transistor at its output which is adapted to be a high impedance point for conveying this current to the said third port.
Claim 2
Dependent Claim
206 words
A three-port electrical network that has a first port whose impedance is high and whose voltage controls the potential of a second port exhibiting substantially zero impedance and through which an independent current flows to reappear at a third port where impedance is high comprising a unity gain transistorized amplifying stage whose control electrode is connected to the said first port of the network, whose output is connected to the said second port and also to a first source of constant biasing current and whose input is connected to a voltage bias source through an impedance, a current follower comprising a transistor whose output is connected to a second source of constant biasing current equal in magnitude to the biasing current form the first source, whose input is connected to the said voltage bias source through an impedance, and whose control electrode is connected to the input of the said amplifying stage such that the current follower provides at its output a current related in magnitude to the current flowing into the said second port, and means comprising a connection to said current follower transistor at its output which is adapted to be a high impedance point for conveying this current to the said third port.
Claim 3
Dependent Claim
21 words
A three-port electrical network as in claim 1 in which the amplifying stage is a transistor operating as an emitter follower.
Claim 4
Dependent Claim
51 words
means for extracting a current equal to the current flowing in the said output port of the buffer amplifier including the said fourth transistor which provides at its output a current equal to the current flowing in the said output port plus the current obtained from the third bias current source,
Claim 5
Dependent Claim
51 words
means for extracting a current equal to the current flowing in the said output port of the buffer amplifier including the said fourth transistor which provides at its output a current equal to the current flowing in the said output port plus the current obtained from the third bias current source,
Claim 6
Dependent Claim
61 words
current follower means including a fifth transistor connected to the output of the fourth transistor and a sixth, diode-connected transistor energized by a fourth source of bias current equal to the third, the control electrodes of said fifth and sixth transistors being interconnected such that a current flows in the sixth transistor equal to the current in the fifth transistor, and
Claim 7
Dependent Claim
61 words
current follower means including a fifth transistor connected to the output of the fourth transistor and a sixth, diode-connected transistor energized by a fourth source of bias current equal to the third, the control electrodes of said fifth and sixth transistors being interconnected such that a current flows in the sixth transistor equal to the current in the fifth transistor, and
Claim 8
Dependent Claim
5 words
A three-port electrical network comprising:
Claim 9
Dependent Claim
5 words
A three-port electrical network comprising:
Claim 10
Dependent Claim
29 words
means comprising a connection to the sixth transistor at its output which is adapted to be a high impedance point for conveying this current to the said third port.
Claim 11
Dependent Claim
29 words
means comprising a connection to the sixth transistor at its output which is adapted to be a high impedance point for conveying this current to the said third port.
Claim 12
Dependent Claim
98 words
A three-port network as in claim 3 wherein the constant bias current sources comprise a transistor whose input is connected via a first resistor of known resistance value to a constant voltage supply and whose control input is connected via two diodes and a second resistor equal in value to the first resistor to an equal constant voltage supply and to a fixed voltage reference via a third resistor equal in value to said first and second resistors, said transistor providing at its output a current having a value related only to the supply voltage and the resistors.
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) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |