US3931577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio receiver protection arrangement
Assignee: Amalgamated Wireless Australasia Ltd
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Filing: 1974-07-02
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Granted: 1976-01-06
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Expires: 1994-07-02
Abstract
Abstract A receiver protection arrangement in which a voltage dependent on aerial voltage and a voltage dependent on aerial current are aggregated and applied to means responsive to a predetermined aggregate level to effectively short circuit the aerial lead. Additional means may be provided to dissipate energy in the input stage of a protected receiver to cause a reduced impedance to be reflected across the output of the protective arrangement.
Inventors
- 👤 Robert Leigh Barnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:46
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/50; H02; H02H; H02H3/00; H02H3/02; H02H3/021; H02H3/023; H02H3/08; H02H3/10; H02H7/00; H02H7/20; H02H9/00; H02H9/04; H02H9/041; H03; H03H; H03H2/00; H03H2/005; H03H2/008; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
135 words
A radio receiver protection arrangement comprising: an aerial input terminal; an output terminal adapted to be coupled to the input of a radio receiver; an aerial lead connected between said input and output terminals; rectifier means connected to said aerial lead for providing a first unidirectional signal representative of peak voltage on said aerial lead; rectifier means coupled to said aerial lead for providing a second unidirectional signal representative of current through said aerial lead; means for combining said first and second signals to form a third signal representative of the aggregate levels of said first and second signals; an electronic switch connected between said aerial lead and ground; and means responsive to said third signal for closing said electronic switch to shunt said input signal therethrough at a predetermined level of said third signal.
Claim 2
Dependent Claim
135 words
A radio receiver protection arrangement comprising: an aerial input terminal; an output terminal adapted to be coupled to the input of a radio receiver; an aerial lead connected between said input and output terminals; rectifier means connected to said aerial lead for providing a first unidirectional signal representative of peak voltage on said aerial lead; rectifier means coupled to said aerial lead for providing a second unidirectional signal representative of current through said aerial lead; means for combining said first and second signals to form a third signal representative of the aggregate levels of said first and second signals; an electronic switch connected between said aerial lead and ground; and means responsive to said third signal for closing said electronic switch to shunt said input signal therethrough at a predetermined level of said third signal.
Claim 3
Dependent Claim
96 words
The radio receiver protection arrangement recited in claim 1 wherein: said rectifier means for providing a first signal comprises a solid state peak rectifier; said rectifier means for providing said second signal comprises: a transformer employing a portion of said aerial lead as its primary; a resistor connected across the secondary of said transformer; and a second solid state rectifier in series with said resistor; said means for combining said first and second signals comprises a capacitor connected to the output of said peak rectifier, said second rectifier and said resistor being connected across said capacitor.
Claim 4
Dependent Claim
34 words
The radio receiver protection arrangement recited in claim 1 wherein: said means for closing said electronic switch comprises a trigger circuit coupled between said means for forming a third signal and said electronic switch.
Claim 5
Dependent Claim
114 words
The radio receiver protection arrangement recited in claim 1 wherein a selector filter transformer of said radio receiver is coupled to said output terminal, said protection arrangement further comprising: means coupled across the secondary of said selector filter transformer for limiting the peak RF voltage across said secondary when the peak RF voltage exceeds a predetermined safe value, said limiting means comprising: a zener diode, means for biasing said zener diode to a predetermined level and diode means coupled between said diode means and ground; whereby current through said rectifier means for providing a second signal is increased causing said means for closing said electronic switch to operate to thereby close said electronic switch.
Claim 6
Dependent Claim
34 words
The radio receiver protection arrangement recited in claim 4 wherein said diode means comprises a pair of diodes, said zener diode being coupled between a point common to said pair of diodes and ground.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-05 | 1979-07-07 | 1980-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-05 | 1983-07-07 | 1984-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-05 | 1987-07-07 | 1988-01-06 | $7700.00 | Window Closed / Lapsed |