Patent US4804927A successfully refreshed from Google Patents.
US4804927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current amplifier circuit
Assignee: Nippon Precision Circuits Inc
•
Filing: 1987-08-31
•
Granted: 1989-02-14
•
Expires: 2007-08-31
Abstract
Abstract A current amplifier circuit has a first transistor with a collector and a base which are electrically connected, a second transistor connected in series with the first transistor and having a collector and a base which are electrically connected. A third and fourth transistor are connected in series with the collector of the first transistor connected to a base of the third transistor and the collector of the second transistor connected to a base of the fourth transistor through a resistor having a resistance R. The first, second, third and fourth transistors have the same polarity. An amplified output signal current R·i/R E is obtained from a collector of the third transistor, wherein R E is the emitter resistance of the fourth transistor and i is the input signal applied to the base of the fourth transistor.
Inventors
- 👤 Akira Yamakoshi
- 👤 Toyohiko Fujita
- 👤 Kunihiko Tsukakoshi
- 👤 Shinji Anraku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:06
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/34; H03F3/343
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
142 words
A current amplifier circuit comprising: a first transistor having a collector and a base which are electrically connected, a second transistor connected in series with the first transistor and having a collector and a base which are electrically connected, a third and a fourth transistor connected in series, wherein the collector of the first transistor is connected to a base of the third transistor and the collector of the second transistor is connected to a base of the fourth transistor through a resistor having a resistance R, wherein the first, second, third and fourth transistors have the same polarity, wherein an amplified output signal current R·i/R E is obtained from a collector of the third transistor when an input signal current i is applied to the base of the fourth transistor, and wherein R E is emitter resistance of the fourth transistor.
Claim 2
Dependent Claim
142 words
A current amplifier circuit comprising: a first transistor having a collector and a base which are electrically connected, a second transistor connected in series with the first transistor and having a collector and a base which are electrically connected, a third and a fourth transistor connected in series, wherein the collector of the first transistor is connected to a base of the third transistor and the collector of the second transistor is connected to a base of the fourth transistor through a resistor having a resistance R, wherein the first, second, third and fourth transistors have the same polarity, wherein an amplified output signal current R·i/R E is obtained from a collector of the third transistor when an input signal current i is applied to the base of the fourth transistor, and wherein R E is emitter resistance of the fourth transistor.
Claim 3
Dependent Claim
23 words
A current amplifier circuit according to claim 1, wherein the collector and the base of the second transistor are connected through a resistor.
Claim 4
Dependent Claim
21 words
A current amplifier circuit according to claim 1, wherein the collector and the base of the second transistor are directly connected.
Claim 5
Dependent Claim
113 words
A current amplifier circuit comprising: a first transistor having a base and a collector connected together and receptive of a bias current, and an emitter; a second transistor having a base and a collector electrically connected; a third transistor having a base connected to the collector of the first transistor, an emitter and a collector at which an amplified output signal is obtained; and a fourth transistor having a collector connected to the emitter of the third transistor and a base connected to the collector of the second transistor through a resistor and receptive of an input current to be amplified; wherein the first, second, third and fourth transistors have the same polarity.
Claim 6
Dependent Claim
113 words
A current amplifier circuit comprising: a first transistor having a base and a collector connected together and receptive of a bias current, and an emitter; a second transistor having a base and a collector electrically connected; a third transistor having a base connected to the collector of the first transistor, an emitter and a collector at which an amplified output signal is obtained; and a fourth transistor having a collector connected to the emitter of the third transistor and a base connected to the collector of the second transistor through a resistor and receptive of an input current to be amplified; wherein the first, second, third and fourth transistors have the same polarity.
Claim 7
Dependent Claim
18 words
The circuit according to claim 4, wherein the base and collector of the second transistor are directly connected.
Claim 8
Dependent Claim
20 words
The circuit according to claim 4, wherein the base and collector of the second transistor are connected through a resistor.
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) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |