Patent US4388809A successfully refreshed from Google Patents.
Patent US3569847A successfully refreshed from Google Patents.
US3569847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifier system for driving shaker motors
Assignee: Lockheed Martin Corp
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Filing: 1969-06-23
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Granted: 1971-03-09
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Expires: 1989-06-23
Abstract
Abstract A modular bridge-type solid-state amplifier capable of delivering several kilowatts of audiofrequency power over a frequency range of zero to approximately 7,500 Hertz and which has an output impedance selectively variable from substantially zero to approximately 100,000 ohms. The amplifier employs both positive and negative feedback, with the selected output impedance being obtained by varying the amount of signal feedback to the preamplifier from the output terminals and an output current sensor. The amplifier may readily be expanded to obtain either voltage or current gain, or both, by adding appropriate modules in series and parallel arrangements, or combinations thereof.
Inventors
- 👤 Robert H Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:37
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3081; G; G01; G01M; G01M7/00; G01M7/02; G01M7/022
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
216 words
A multistage, direct-coupled, transistor amplifier circuit comprising, in combination: input terminals for supplying an input signal; a preamplifier having a single ended input connected to said input terminals, and having a push-pull output; first and second buffer amplifiers direct-coupled to respective push-pull outputs of said preamplifier, each of said buffer amplifiers comprising: first and second transistor gain stages of opposite conductivity type, each including base, emitter, and collector electrodes; means connecTing the collector electrode of said first transistor to the base of said second transistor; means providing an output circuit connected with the collector electrode of said second transistor; and a Zener diode connected in the emitter circuit of said second transistor to provide a return path for the collector electrode of said first transistor; first and second power amplifiers connected to provide a bridge amplifier configuration; said first and second power amplifiers each comprising: a multiple-stage emitter-follower amplifier having its input connected to the output of said first buffer amplifier for amplifying the positive half cycles of the signal received therefrom; and a multiple-stage complementary cascade amplifier having its input connected to the output of said second buffer amplifier for amplifying the negative half cycles of the signal received therefrom; and a load device connected between the outputs of said first and second power amplifiers.
Claim 2
Dependent Claim
354 words
A multistage, direct-coupled, transistor amplifier circuit comprising, in combination: input terminals for supplying an input signal; a preamplifier having a single-ended input connected to said input terminals, and having a push-pull output; first and second buffer amplifiers direct-coupled to respective push-pull outputs of said preamplifier; a load device; and first and second power amplifiers connected to provide a bridge-amplifier configuration said first and second power amplifiers each comprising: a first transistor input amplifier having its input connected to the output of said first buffer amplifier; a first transistor predriver amplifier direct-coupled to the output of said first input amplifier; means for providing a source of positive operating potential; a first driver amplifier, comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected in common to the output of said first predriver amplifier, the collectors thereof being connected to said source of positive operating potential; a first output amplifier comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected to the emitters of respective transistor stages of said first driver amplifier, the collectors thereof being connected to said source of positive operating potential, and the emitters thereof being connected to said load device; means for providing a source of negative operating potential; a second transistor input amplifier having its output connected to the output of said second buffer amplifier; a second transistor predriver amplifier direct-coupled to the output of said second input amplifier; a second driver amplifier, comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected in common to the output of said second predriver amplifier, the collectors thereof being connected to said load device; and a second output amplifier comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected to the emitters of respective transistor stages of said second driver amplifier, the collectors thereof being connected to said load device and the emitters thereof being connected to said source of negative operating potential.
Claim 3
Dependent Claim
164 words
A multistage, direct-coupled, transistor amplifier circuit comprising, in combination: input terminals for supplying an input signal; a preamplifier having a single ended input connected to said input terminals, and having a push-pull output; first and second buffer amplifiers direct-coupled to respective push-pull outputs of said preamplifier; first and second power amplifiers, the respective inputs of which are direct-coupled to the outputs of corresponding ones of said buffer amplifiers, the outputs of said poWer amplifiers having a bridge amplifier configuration; a first pair of negative feedback loops connected from the outputs of said power amplifiers to the input of said preamplifier; a second pair of negative feedback loops connected from the outputs of said power amplifiers to the inputs of corresponding ones of said buffer amplifiers; means for selectively changing the operating mode of said first pair of feedback loops from a current feedback mode to a voltage feedback mode; and a load device connected between the outputs of said first and second power amplifiers.
Claim 4
Dependent Claim
127 words
A multistage, direct-coupled, transistor amplifier circuit comprising, in combination: input terminals for supplying an input signal; a preamplifier having a single ended input connected to said input terminals, and having a push-pull output; first and second buffer amplifiers direct-coupled to respective push-pull outputs of said preamplifier; first and second power amplifiers, the respective inputs of which are direct-coupled to the outputs of corresponding ones of said buffer amplifiers, the outputs of said power amplifiers having a bridge amplifier configuration; a load device connected between the outputs of said first and second power amplifiers; and time delayed switch means for rendering said first and second power amplifiers operative after said preamplifier and said buffer amplifiers have become operative, thereby suppressing adverse turn-on transients from reaching said load device.
Claim 5
Dependent Claim
392 words
A multistage, direct-coupled, transistor amplifier circuit comprising, in combination: input terminals for supplying an input signal; a preamplifier having a single ended input connected to said input terminals, and having a push-pull output; first and second buffer amplifiers direct-coupled to respective push-pull outputs of said preamplifier; first and second power amplifiers each comprising: a first transistor input amplifier having its input connected to the output of said first buffer amplifier; a first transistor predriver amplifier direct-coupled to the output of said first input amplifier; means for providing a source of positive operating potential; a first driver amplifier, comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected in common to the output of said first predriver amplifier, the collectors thereof being connected to said source of positive operating potential; a first output amplifier comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected to the emitters of respective transistor stages of said first driver amplifier, the collectors thereof being connected to said source of positive operating potential, and the emitters thereof being connected to said load device; means for providing a source of negative operating potential; a second transistor input amplifier having its output connected to the output of said second buffer amplifier; a second transistor predriver amplifier direct-coupled to the output of said second input amplifier; a second driver amplifier, comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected in common to the output of said second predriver amplifier, the collectors thereof being connected to said load divide and a second output amplifier comprising a plurality of transistor stages each including a base, an emitter, and a collector, the bases thereof being connected to the emitters of respective transistor stages of said second driver amplifier, the collectors thereof being connected to said load device and the emitters thereof being connected to said source of negative operating potential; a load device connected between the outputs of said first and second power amplifiers; and time delay switching means connected to said first and second input amplifiers and to said first and second driver amplifiers for selectively controlling the application of input signals thereto, thereby suppressing turn-on transients from reaching said load device.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |