Patent US3787802A successfully refreshed from Google Patents.
US3787802A
Expired / Lapsed
US
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Automatic range switching for digital depth sounders
Assignee: Heath Co
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Filing: 1972-05-08
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Granted: 1974-01-22
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Expires: 1992-05-08
Abstract
Abstract A depth sounder instrument having automatic range switching in which an oscillator and a divider produce timing pulse trains at two different frequencies which are related to the propagation velocity of the depth sounder transmitted pulse. A selected one of the pulse trains is delivered to a digital counter during the interval between the transmitted energy pulse and the received pulse, the latter having been reflected from the bottom of the body of water. The apparatus includes logic means responsive to the count arrived at during this interval to select the total instrument range for the next interval, this range being chosen by the selection of the pulse train. If the count accumulated during the interval is appropriate to the previously selected range, no change is made. However, if the count is either much smaller than, or greater than, the counter capacity, the other frequency is chosen, thereby causing the counters to accumulate at a faster or slower rate. The frequencies are preferably related by a power of 10 and a decimal point can then be illuminated or not, depending upon the range and frequency chosen.
Inventors
- 👤 R Brahman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:27
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/02; G01S15/06; G01S15/08; G01S15/10; G01S15/18; G01S15/14; G01S7/00; G01S7/52; G01S7/523; G01S7/526; G01S7/527
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
288 words
An automatic range switching apparatus for use in a distance measuring system of the type having means for transmitting an energy pulse, means for receiving a reflected pulse and means for timing the transmission of pulses, the apparatus comprising the combination of means for generating trains of timing pulses at different first and second frequencies; means for producing one of a first selection signal when in a first state and a second selection signal when in a second state; means for selecting a train of timing pulses at one of said first and second frequencies in response to one of said first and second selection signals, respectively; means for gating the selected train of timing signals, said gating means being enabled by the transmitted pulses and disabled by the received pulses; means for counting the selected train of pulses during said interval between the transmitted pulses and received pulses, said counter having a predetermined capacity: means for producing an inhibit pulse when both the count accumulated in said counter is less than a first predetermined total and when said means for producing a selection signal is in a second state; means connected to said means for producing an inhibit pulse for inhibiting the received pulses; means for displaying the count accumulated by said means for counting; said means for producing one of said selection signals changing from the first state to the second state when the count accumulated by said means for counting exceeds said predetermined capacity during said interval, and to change from the second state to the first state when both said means for producing one of said selection signals is in the second state and said means for counting exceeds predetermined total during said interval.
Claim 2
Dependent Claim
288 words
An automatic range switching apparatus for use in a distance measuring system of the type having means for transmitting an energy pulse, means for receiving a reflected pulse and means for timing the transmission of pulses, the apparatus comprising the combination of means for generating trains of timing pulses at different first and second frequencies; means for producing one of a first selection signal when in a first state and a second selection signal when in a second state; means for selecting a train of timing pulses at one of said first and second frequencies in response to one of said first and second selection signals, respectively; means for gating the selected train of timing signals, said gating means being enabled by the transmitted pulses and disabled by the received pulses; means for counting the selected train of pulses during said interval between the transmitted pulses and received pulses, said counter having a predetermined capacity: means for producing an inhibit pulse when both the count accumulated in said counter is less than a first predetermined total and when said means for producing a selection signal is in a second state; means connected to said means for producing an inhibit pulse for inhibiting the received pulses; means for displaying the count accumulated by said means for counting; said means for producing one of said selection signals changing from the first state to the second state when the count accumulated by said means for counting exceeds said predetermined capacity during said interval, and to change from the second state to the first state when both said means for producing one of said selection signals is in the second state and said means for counting exceeds predetermined total during said interval.
Claim 3
Dependent Claim
49 words
An apparatus according to claim 1 wherein the means for producing said first and second selection signals comprises a bistable multivibrator in which the first stable state of said bistable multivibrator generates the first selection signal and second bistable state of said bistable multivibrator generates the second selection signal.
Claim 4
Dependent Claim
28 words
An apparatus according to claim 1 wherein the means for generating said first and second frequency timing pulses comprises a fixed frequency pulse oscillator and a decade counter.
Claim 5
Dependent Claim
18 words
An apparatus according to claim 3 wherein said fixed frequency pulse oscillator generates pulses at substantially 24 kHz.
Claim 6
Dependent Claim
211 words
In a system for measuring the duration of a varying time interval by counting the number of pulses of known frequency during the time interval, the system being of a type including a repetition rate oscillator for initiating a measurement cycle repetitively, an apparatus comprising; oscillator means for generating timing pulses; means for counting said timing pulses; means for displaying the count accumulated by said means for counting during the time interval, said means for displaying having a limited number of displayable digits; means for changing the frequency of said oscillator means in discreet steps, said means for changing the frequency being responsive to said means for counting to decrease the frequency of said oscillator means when the count accumulated by said means for counting exceeds a predetermined count and to increase said oscillator frequency when the count accumulated by said means for counting is less thAn a predetermined count, whereby the measuring system maintains the resolution ratio within preselected limits, said resolution ratio being defined as the ratio of the measured time interval to the number of displayed digits; and means responsive to said means for changing the frequency for immediately retriggering the repetition rate oscillator to initiate a next measurement cycle substantially at the completion of the time interval.
Claim 7
Dependent Claim
211 words
In a system for measuring the duration of a varying time interval by counting the number of pulses of known frequency during the time interval, the system being of a type including a repetition rate oscillator for initiating a measurement cycle repetitively, an apparatus comprising; oscillator means for generating timing pulses; means for counting said timing pulses; means for displaying the count accumulated by said means for counting during the time interval, said means for displaying having a limited number of displayable digits; means for changing the frequency of said oscillator means in discreet steps, said means for changing the frequency being responsive to said means for counting to decrease the frequency of said oscillator means when the count accumulated by said means for counting exceeds a predetermined count and to increase said oscillator frequency when the count accumulated by said means for counting is less thAn a predetermined count, whereby the measuring system maintains the resolution ratio within preselected limits, said resolution ratio being defined as the ratio of the measured time interval to the number of displayed digits; and means responsive to said means for changing the frequency for immediately retriggering the repetition rate oscillator to initiate a next measurement cycle substantially at the completion of the time interval.
References Cited (Backward Citations)
US3500189A
Cited
GB1212016A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |