Patent US3766486A successfully refreshed from Google Patents.
US3766486A
Expired / Lapsed
US
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Arrangement to keep the range of control of a control element within desired limits
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1972-06-12
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Granted: 1973-10-16
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Expires: 1992-06-12
Abstract
Abstract An arrangement to keep the range of control of a control element within desired limits especially for signal level regulation by means of a pilot signal, for example, in the repeaters of a carrier frequency system in which a control signal dependent on the amplitude of the pilot signal sets a control element which determines the amplification of the respective repeater. The arrangement controls the current which feeds the control element. The arrangement contains a first and a second parallel current branch each containing a voltage divider whose tap is connected to a definite potential through a Zener diode for limiting the current in either direction. The attenuation characteristic of the control element thus has two break points one in the lower part of the range of control and one in the upper part due to the current limitation and the amplification of the repeater becomes constant outside a range determined by the break points.
Inventors
- 👤 F Ouvrier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:31
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/005
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
213 words
Apparatus for limiting the range of operation of a currentsensitive control element which regulates the level of a signal, said apparatus comprising: a current source having an output terminal and a return terminal, one of said terminals being connected to said current-sensitive control element; and first and second current control circuits connected in parallel between the other terminal of said current source and said currentsensitive control element, said first current control circuit comprising first and second resistors connected in series and a Zener diode connected between the junction of said resistors and a terminal of said current source to establish a fixed potential at said junction for stabilizing the minimum current through said circuit, to said current-sensitive control element, said second current control circuit comprising current valving means for controlling the flow of current therethrough in accordance with the amplitude of the signal whose level is to be regulated, third and fourth resistors, said current valving means, said third resistor and said fourth resistor being connected in series, and another Zener diode connected between the junction of said third and fourth resistors and a terminal of said current source for shunting current around said current-sensitive control element to establish a maximum limit for current passing through said circuit to said current-sensitive control element.
Claim 2
Dependent Claim
213 words
Apparatus for limiting the range of operation of a currentsensitive control element which regulates the level of a signal, said apparatus comprising: a current source having an output terminal and a return terminal, one of said terminals being connected to said current-sensitive control element; and first and second current control circuits connected in parallel between the other terminal of said current source and said currentsensitive control element, said first current control circuit comprising first and second resistors connected in series and a Zener diode connected between the junction of said resistors and a terminal of said current source to establish a fixed potential at said junction for stabilizing the minimum current through said circuit, to said current-sensitive control element, said second current control circuit comprising current valving means for controlling the flow of current therethrough in accordance with the amplitude of the signal whose level is to be regulated, third and fourth resistors, said current valving means, said third resistor and said fourth resistor being connected in series, and another Zener diode connected between the junction of said third and fourth resistors and a terminal of said current source for shunting current around said current-sensitive control element to establish a maximum limit for current passing through said circuit to said current-sensitive control element.
Claim 3
Dependent Claim
40 words
The apparatus of claim 1 further comprising an isolation means in at least one of said current control circuits for isolating the effect of current in one of said current control circuits on the other of said current control circuits.
Claim 4
Dependent Claim
67 words
The apparatus of claim 1 further comprising a third current control circuit connected in parallel with said first current control circuit, said third current control circuit comprising a signal amplitude sensitive switch means and a fifth resistor connected in series, said signal amplitude sensitive switch means switching to a conductive state when the amplitude of the signal whose level is being regulated falls below a predetermined value.
Claim 5
Dependent Claim
35 words
The apparatus of claim 3 further comprising an isolation means in said first current control circuit for isolating the effect of current in one of said current control circuits on the other current control circuits.
References Cited (Backward Citations)
US3302175A
Cited
US3470480A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |