Patent US3743754A successfully refreshed from Google Patents.
US3743754A
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US
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Loran signal synthesizer
Assignee: Singer Co
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Filing: 1971-09-01
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Granted: 1973-07-03
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Expires: 1991-09-01
Abstract
Abstract This specification describes a Loran simulator for simulating both type A and type C Loran signals. A pulse generator for generating Loran C pulse trains is driven from a counter. The counter has timing pulses supplied to it from a clock. The output of the counter, when a prescribed count is reached, triggers the generation of the Loran C pulses. In addition, the Loran A pulse generator is triggered by an output of the Loran C generator. Separate output terminals are provided for each type of Loran pulse trains. A control device supplies the counter at the beginning of each cycle with a number whose value determines the time interval until the generation of the next pulse train. The control device may be manually operable or automatically operated. Radio frequency phasing effects are also generated.
Inventors
- 👤 R Eisenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:15
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/26; G01; G01S; G01S1/00; G01S1/02; G01S1/022; G01S1/028
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
281 words
Apparatus for training navigators in the use of navigational equipment designed to indicate the position of a receiver which receives the transmission from several transmitters whose locations are precisely known, said apparatus comprising means for generating signals which simulate the transmission from the transmitters, and receivers for comparing several of said simulated transmissions; said generating means comprising a source of electrical pulse trains, which pulse trains are separated in time by intervals whose length is dependent upon the simulated position of said receiver with respect to said simulated transmitters; means for producing selected time intervals comprising a counter, meanS for loading said counter with a number whose value is proportional to the time interval to be produced, a clock for generating fixed frequency clock pulses, and means for connecting the output from said clock to the input to said counter to drive said counter through its count from the value of the number loaded therein so that said counter generates an output signal when it reaches the end of its count; a pulse generator responsive to the output from said counter to generate a prescribed number of output pulses; a source of high-frequency energy; a modulator; means for connecting the outputs from said source of high-frequency energy and said pulse generator to the inputs of said modulator so that said modulator produces at its output pulses of high-frequency energy; means for determining the polarity of the first cycle of high-frequency energy in each of said pulses of high-frequency energy in accordance with a prescribed schedule; and means for applying the output of said determining means to a navigation receiver where it is compared with the outputs of other similar determining means.
Claim 2
Dependent Claim
281 words
Apparatus for training navigators in the use of navigational equipment designed to indicate the position of a receiver which receives the transmission from several transmitters whose locations are precisely known, said apparatus comprising means for generating signals which simulate the transmission from the transmitters, and receivers for comparing several of said simulated transmissions; said generating means comprising a source of electrical pulse trains, which pulse trains are separated in time by intervals whose length is dependent upon the simulated position of said receiver with respect to said simulated transmitters; means for producing selected time intervals comprising a counter, meanS for loading said counter with a number whose value is proportional to the time interval to be produced, a clock for generating fixed frequency clock pulses, and means for connecting the output from said clock to the input to said counter to drive said counter through its count from the value of the number loaded therein so that said counter generates an output signal when it reaches the end of its count; a pulse generator responsive to the output from said counter to generate a prescribed number of output pulses; a source of high-frequency energy; a modulator; means for connecting the outputs from said source of high-frequency energy and said pulse generator to the inputs of said modulator so that said modulator produces at its output pulses of high-frequency energy; means for determining the polarity of the first cycle of high-frequency energy in each of said pulses of high-frequency energy in accordance with a prescribed schedule; and means for applying the output of said determining means to a navigation receiver where it is compared with the outputs of other similar determining means.
Claim 3
Dependent Claim
46 words
The apparatus defined in claim 1 further including gating means interposed between said clock and said counter, and means for connecting selected outputs from said counter to said gating means to inhibit the passage of pulses through said gating means when said counter reaches prescribed counts.
Claim 4
Dependent Claim
170 words
Apparatus for driving a Loran C receiver to simulate the reception of Loran C transmissions, said apparatus comprising means for generating trains of pulses representing both master and slave transmissions, said generating means comprising a source of electrical pulses, a chain of gating means connected in series with each other with the output of one gate serving as one input to the next gate, means for applying the output of said source of pulses to the input to the first gate in said chain of gates, a counter, means for applying the output from said source of pulses to the count input of said counter, means for connecting individual count outputs from said counter to individual inputs to said gates to control the passage through said gates of individual pulses from said source, an interval timer, and means for applying the output from said interval timer to the inputs of gates in said chain of gates to prevent the passage of pulses therethrough except at appropriate selected intervals of time.
Claim 5
Dependent Claim
170 words
Apparatus for driving a Loran C receiver to simulate the reception of Loran C transmissions, said apparatus comprising means for generating trains of pulses representing both master and slave transmissions, said generating means comprising a source of electrical pulses, a chain of gating means connected in series with each other with the output of one gate serving as one input to the next gate, means for applying the output of said source of pulses to the input to the first gate in said chain of gates, a counter, means for applying the output from said source of pulses to the count input of said counter, means for connecting individual count outputs from said counter to individual inputs to said gates to control the passage through said gates of individual pulses from said source, an interval timer, and means for applying the output from said interval timer to the inputs of gates in said chain of gates to prevent the passage of pulses therethrough except at appropriate selected intervals of time.
Claim 6
Dependent Claim
18 words
The apparatus defined in claim 3 wherein said chain of gates comprises NAND gates followed by signal inverters.
Claim 7
Dependent Claim
95 words
The apparatus defined in claim 3 wherein said interval timer comprises a counter, a control means for supplying a digital value to said counter, means for connecting the output of said source of pulses to the input of said counter so that said counter counts said pulses starting with the value it receives from said control means, said counter generating an output signal when its count reaches the capacity of said counter, and means connected to the output of said counter for interrupting further counting by said counter when said counter produces an output signal.
Claim 8
Dependent Claim
47 words
The apparatus defined in claim 5 further including means for generating a radio frequency signal, means for modulating said radio frequency signal by the pulse train generated by said generator, and means for controlling the polarity of the first half-wave of each pulse of radio frequency energy.
Claim 9
Dependent Claim
39 words
The apparatus defined in claim 6 wherein said means for controlling polarity comprises a single-pole double-throw switch, means for controlling said switch, and means for applying to the two positions of said switch opposite polarities of said modulated pulse.
Claim 10
Dependent Claim
110 words
The apparatus defined in claim 7 wherein said switch control means comprises a shift register, means for inserting into said shift register a digital word representative of the polarities of the pulses in a train of pulses, each digit of said word representing the polarity of the first half-wave of a pulse in said train of pulses, means for cAusing the contents of said register to shift to a new position when a new pulse is to be applied to said switch, and means for applying the digit in a selected digit position of said register to the control input of said switch to control the throw of said switch.
Claim 11
Dependent Claim
81 words
The apparatus defined in claim 8 further including means for controlling the amplitude of the output from said switch, said amplitude control means comprising a multiplexing means, means for applying to said multiplexing means a plurality of amplitude control signals, an amplitude modulator connected to the output of said switch means, means for connecting the output of said multiplexing means to said modulator, and means for selecting which of said amplitude control signals is applied to said modulator at any time.
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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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |