US3571618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video logarithmic amplifier
Assignee: United States Department of the Navy
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Filing: 1968-07-23
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Granted: 1971-03-23
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Expires: 1988-07-23
Abstract
Abstract A logarithmic amplifier having a feedback transistor in which the amplifier''s input is resistively connected to a DC amplifier and is biased with a power supply resistively connecting the output of the DC amplifier by a pair of diodes and connecting the input by a diode and resistor.
Inventors
- 👤 Henry F Inacker
- 👤 Miles C Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:04
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
163 words
A video logarithmic amplifier comprising a logarithmic amplifier and a post amplifier wherein the logarithmic amplifier comprises: a. A DC amplifier having an input and output; b. an input resistor connected to the input of the DC amplifier; c. a biasing voltage source; d. a second resistor connected to the biasing voltage source; e. a first diode interposed between the second resistor and the output terminals of the DC amplifier with a polarity to provide easy current flow from the second resistor to the DC amplifier output; f. a third resistor and a second diode in series interposed between the second resistor and the input of the DC amplifier, the second diode having a polarity to provide easy current flow from the second resistor to the input of the DC amplifier; and g. a transistor having a collector and emitter, the collector being connected to the input of the DC amplifier and the emitter being connected to the output of the DC amplifier.
Claim 2
Dependent Claim
163 words
A video logarithmic amplifier comprising a logarithmic amplifier and a post amplifier wherein the logarithmic amplifier comprises: a. A DC amplifier having an input and output; b. an input resistor connected to the input of the DC amplifier; c. a biasing voltage source; d. a second resistor connected to the biasing voltage source; e. a first diode interposed between the second resistor and the output terminals of the DC amplifier with a polarity to provide easy current flow from the second resistor to the DC amplifier output; f. a third resistor and a second diode in series interposed between the second resistor and the input of the DC amplifier, the second diode having a polarity to provide easy current flow from the second resistor to the input of the DC amplifier; and g. a transistor having a collector and emitter, the collector being connected to the input of the DC amplifier and the emitter being connected to the output of the DC amplifier.
Claim 3
Dependent Claim
23 words
A video logarithmic amplifier according to claim 1 which further comprises an emitter-follower transistor circuit connected to the output of the DC amplifier.
Claim 4
Dependent Claim
23 words
A video logarithmic amplifier according to claim 2 which further comprises a nonlinear feedback post amplifier circuit fed by the emitter-follower transistor circuit.
References Cited (Backward Citations)
US3128377A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-22 | 1974-09-21 | 1975-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-22 | 1978-09-21 | 1979-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-22 | 1982-09-21 | 1983-03-23 | $7700.00 | Window Closed / Lapsed |