US3604945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regenerative tone decoder
Assignee: United States Department of the Navy
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Filing: 1968-11-05
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Granted: 1971-09-14
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Expires: 1988-11-05
Abstract
Abstract For a spacecraft command system, a tone decoder which distinguishes between binary zeros and ones. The circuit combines the operations of a differential amplifier, a threshold detector, a Schmitt trigger and a fast-reset integrator in a single circuit which uses fewer components than would be required if these operations were cascaded, as in the prior art.
Inventors
- 👤 Eric J Hoffman
- 👤 Reginald M Rhue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:18
CPC Classifications
G; G08; G08C; G08C19/00; G08C19/12; G08C19/16; G08C19/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
227 words
In combination with a redundant command system including a pair of receivers and a linear amplifier, a tone decoder connected to the output of the linear amplifier and comprising: a pair of input filters connected to the linear amplifier, a differential amplifier connected to the filters and receiving tone signals form the filters, an integrator circuit means including a capacitor connected to said differential amplifier, said differential amplifier having a pair of outputs for indicating the presence of a binary zero or a binary one in the tone signals produced by the receivers or either of them and including, a first pair of transistors connected to the filters and having a common output connected to the integrator and a second pair of transistors connected to the filters and to the first pair of transistors for controlling said first pair of transistors, and control means connected in parallel with the capacitor of said integrating circuit means and to the common output of said first pair of transistors for controlling the integrator, the collector of one of the transistors of said first pair of transistors, the base of one of the transistors of said second pair of transistors and one of the filters being connected to define a feedback loop to effect the action of a Schmitt trigger when said transistor of said first pair of transistors in conducting.
Claim 2
Dependent Claim
227 words
In combination with a redundant command system including a pair of receivers and a linear amplifier, a tone decoder connected to the output of the linear amplifier and comprising: a pair of input filters connected to the linear amplifier, a differential amplifier connected to the filters and receiving tone signals form the filters, an integrator circuit means including a capacitor connected to said differential amplifier, said differential amplifier having a pair of outputs for indicating the presence of a binary zero or a binary one in the tone signals produced by the receivers or either of them and including, a first pair of transistors connected to the filters and having a common output connected to the integrator and a second pair of transistors connected to the filters and to the first pair of transistors for controlling said first pair of transistors, and control means connected in parallel with the capacitor of said integrating circuit means and to the common output of said first pair of transistors for controlling the integrator, the collector of one of the transistors of said first pair of transistors, the base of one of the transistors of said second pair of transistors and one of the filters being connected to define a feedback loop to effect the action of a Schmitt trigger when said transistor of said first pair of transistors in conducting.
Claim 3
Dependent Claim
16 words
The tone decoder specified in claim 1 wherein said integrator control means comprises a silicon-controlled rectifier.
Claim 4
Dependent Claim
205 words
A tone decoder for a spacecraft command system wherein spacecraft commands are in the form of tone signals of either of two frequencies, said tone decoder comprising: a pair of input filters each of which is assigned to receive and filter a different one of said tone signals, a supply voltage source, a biasing current source, a pair of first transistors each having base, emitter and collector elements, the base of each of said transistors being connected to a different one of said input filters, the emitter of each of said transistors being connected to said biasing current source, and the collector of each of said transistors being connected to said supplY voltage source, and a pair of second transistors each having base, emitter and collector elements, the base of each of said second transistors being connected to the collector of a different one of said first transistors, the emitters of said second transistors being connected together and to said supply voltage source, and the collector of each of said second transistors being connected by one of said input filters in a regenerative feedback loop to the base of the associated first transistor whose collector is connected to the base of that same second transistor.
Claim 5
Dependent Claim
205 words
A tone decoder for a spacecraft command system wherein spacecraft commands are in the form of tone signals of either of two frequencies, said tone decoder comprising: a pair of input filters each of which is assigned to receive and filter a different one of said tone signals, a supply voltage source, a biasing current source, a pair of first transistors each having base, emitter and collector elements, the base of each of said transistors being connected to a different one of said input filters, the emitter of each of said transistors being connected to said biasing current source, and the collector of each of said transistors being connected to said supplY voltage source, and a pair of second transistors each having base, emitter and collector elements, the base of each of said second transistors being connected to the collector of a different one of said first transistors, the emitters of said second transistors being connected together and to said supply voltage source, and the collector of each of said second transistors being connected by one of said input filters in a regenerative feedback loop to the base of the associated first transistor whose collector is connected to the base of that same second transistor.
Claim 6
Dependent Claim
51 words
The decoder specified in claim 3 wherein said regenerative feedback is provided by a resistor, one side of which is connected directly to the collector of said second transistor through said one filter to the base of said associated first transistor and the other side of which is connected to ground.
Claim 7
Dependent Claim
81 words
The tone decoder as specified in claim 3 and further including, integrator circuit means, and control means connected to said integrator means and responsive to the conduction state of said second pair of transistors for selectively permitting integrator circuit means to produce an output signal when a tone signal is being received by either of said input filters and for preventing said integrator circuit means from producing said output signal when neither of said output filters is receiving a tone signal.
Claim 8
Dependent Claim
64 words
The tone decoder as specified in claim 5 wherein: said integrator circuit means includes a capacitor connected between said supply voltage source and ground, and said control means is a silicon controlled rectifier having anode, cathode and gate element, said anode and cathode elements being connected across said capacitor, and said gate element being connected to the common emitter connection of said second transistors.
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) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |