US3883813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-frequency power amplifier
Assignee: Shin Shirasuna Electric Corp
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Filing: 1974-02-11
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Granted: 1975-05-13
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Expires: 1994-02-11
Abstract
Abstract In a low-frequency power amplifier designed for Class B or AB operation which comprises a first complementary pair of transistors connected in the form of Darlington connection, and a second complementary pair of transistors connected in the form of Darlington connection, there is provided means for permitting a bias current to flow through said transistors, whether or not there is an input signal, thereby preventing notching distortion.
Inventors
- 👤 Mamoru Sekiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:27
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3217
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
209 words
A low-frequency amplifier circuit arrangement designed for Class ''''B'''' or ''''AB'''' operation, comprising: a first amplifier stage including a first transistor of a first conductivity-type and a second transistor of a seCond conductivity-type having the base thereof connected with the collector of said first transistor; a second amplifier stage including a third transistor of said second conductivity-type and a fourth transistor of said first conductivity-type having the base thereof connected with the collector of said third transistor; said second and fourth transistors having the collectors thereof connected to a load to alternately drive said load; and means for preventing said first and third transistors from being brought into cut-off condition, regardless of whether one of said second and fourth transistors are driving said load; said means comprising bias circuit means connected between the bases of said first and third transistors, a non-grounded resistor through which the emitters of said first and third transistors are connected to each other, a first diode having the anode and cathode thereof connected to the emitter of said first transistor and the collector of said second transistor respectively, and a second diode having the anode and cathode thereof connected to the collector of said fourth transistor and the emitter of said third transistor respectively.
Claim 2
Dependent Claim
209 words
A low-frequency amplifier circuit arrangement designed for Class ''''B'''' or ''''AB'''' operation, comprising: a first amplifier stage including a first transistor of a first conductivity-type and a second transistor of a seCond conductivity-type having the base thereof connected with the collector of said first transistor; a second amplifier stage including a third transistor of said second conductivity-type and a fourth transistor of said first conductivity-type having the base thereof connected with the collector of said third transistor; said second and fourth transistors having the collectors thereof connected to a load to alternately drive said load; and means for preventing said first and third transistors from being brought into cut-off condition, regardless of whether one of said second and fourth transistors are driving said load; said means comprising bias circuit means connected between the bases of said first and third transistors, a non-grounded resistor through which the emitters of said first and third transistors are connected to each other, a first diode having the anode and cathode thereof connected to the emitter of said first transistor and the collector of said second transistor respectively, and a second diode having the anode and cathode thereof connected to the collector of said fourth transistor and the emitter of said third transistor respectively.
References Cited (Backward Citations)
US3550025A
Cited
US3611170A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |