US3909716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital frequency meter
Assignee: Wandel and Golterman GmbH and Co
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Filing: 1973-11-26
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Granted: 1975-09-30
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Expires: 1993-11-26
Abstract
Abstract To measure the recurrence frequency or cadence of the output of a pulse source, a programmer periodically opens a gate for a predetermined measuring interval during which the pulses are fed to a counter whose reading is to be registered in a numerical indicator. The counter, reset by the programmer after each measuring interval, loads the indicator through a buffer register which stores its reading until an updating pulse from the programmer makes the register receptive to a new count. In one embodiment, such updating is inhibited as long as the stored contents of the register differ by only a unit step from the current count. In another embodiment, the pulse cadence of the source is stepped down by a frequency divider inserted between that source and the counter; prior to each measuring cycle, the divider may be automatically preset by the programmer to an initial position, different from its counter-stepping zero position, depending upon the final position reached in the preceding cycle in order to minimize the possibility of digital errors. A further embodiment includes a timing circuit which determines the period between the end of a preceding measuring interval and the immediately following pulse in order to shift the end of the next measuring interval to a time position approximately midway between two pulses, a delay circuit letting the start of such interval occur a fraction of a pulse cycle after reception of a pulse from the source.
Inventors
- 👤 Hermann-Josef Diekers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:42
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
200 words
A system for measuring the output frequency of a source of recurrent pulses, comprising: a metering circuit connected to receive the pulses of said source; a normally closed gate in said circuit; programming means connected to said gate for repeatedly opening same to establish a measuring interval; a pulse counter in said circuit connected to said source by way of said gate, said programming means being connected to said counter for setting same to zero before each measuring interval; a buffer register in said circuit connected to said counter and loadable by the latter in response to an updating signal emitted by said programming means between measuring intervals; and digital indicator means connected to said register for displaying the contents thereof; said register being provided with a control input connected to said programming means for receiving said updating signal therefrom, further comprising blocking means in the connection between said programming means and said control input, and comparison means with input connections to the outputs of said counter and of said register for deactivating said blocking means only in the presence of a difference greater than a unit count between the reading of said counter and the contents of said register.
Claim 2
Independent Claim
200 words
A system for measuring the output frequency of a source of recurrent pulses, comprising: a metering circuit connected to receive the pulses of said source; a normally closed gate in said circuit; programming means connected to said gate for repeatedly opening same to establish a measuring interval; a pulse counter in said circuit connected to said source by way of said gate, said programming means being connected to said counter for setting same to zero before each measuring interval; a buffer register in said circuit connected to said counter and loadable by the latter in response to an updating signal emitted by said programming means between measuring intervals; and digital indicator means connected to said register for displaying the contents thereof; said register being provided with a control input connected to said programming means for receiving said updating signal therefrom, further comprising blocking means in the connection between said programming means and said control input, and comparison means with input connections to the outputs of said counter and of said register for deactivating said blocking means only in the presence of a difference greater than a unit count between the reading of said counter and the contents of said register.
Claim 3
Independent Claim
225 words
A system for measuring the output frequency of a source of recurrent pulses, comprising: a metering circuit connected to receive the pulses of said source; a normally closed gate in said circuit; programming means connected to said gate for repeatedly opening same to establish a measuring interval; a pulse counter in said circuit connected to said source by way of said gate, said programming means being connected to said counter for setting same to zero before each measuring interval; a buffer register in said circuit connected to said counter and loadable by the latter in response to an updating signal emitted by said programming means between measuring intervals; digital indicator means connected to said register for displaying the contents thereof; and a frequency divider of step-down ratio n:1 inserted in said circuit between said gate and said counter for stepping the latter on passing through a zero position at the end of every n-pulse cycle, said frequency divider being connected to said programming means for receiving therefrom a presetting signal establishing prior to each measuring interval an initial position different from said zero position; said frequency divider being provided with logical means connected to the output thereof for determining the final position of said frequency divider at the end of a preceding measuring interval and modifying said initial position in dependence upon said final position.
Claim 4
Independent Claim
225 words
A system for measuring the output frequency of a source of recurrent pulses, comprising: a metering circuit connected to receive the pulses of said source; a normally closed gate in said circuit; programming means connected to said gate for repeatedly opening same to establish a measuring interval; a pulse counter in said circuit connected to said source by way of said gate, said programming means being connected to said counter for setting same to zero before each measuring interval; a buffer register in said circuit connected to said counter and loadable by the latter in response to an updating signal emitted by said programming means between measuring intervals; digital indicator means connected to said register for displaying the contents thereof; and a frequency divider of step-down ratio n:1 inserted in said circuit between said gate and said counter for stepping the latter on passing through a zero position at the end of every n-pulse cycle, said frequency divider being connected to said programming means for receiving therefrom a presetting signal establishing prior to each measuring interval an initial position different from said zero position; said frequency divider being provided with logical means connected to the output thereof for determining the final position of said frequency divider at the end of a preceding measuring interval and modifying said initial position in dependence upon said final position.
Claim 5
Dependent Claim
68 words
A system as defined in claim 2 wherein said logical means is responsive to a final zero position of said frequency divider to preset same into an initial position corresponding to a late part of said n-pulse cycle, said sensing means being responsive to a final pre-zero position of said frequency divider to preset same into an initial position corresponding to an early part of said n-pulse cycle.
Claim 6
Independent Claim
207 words
A system for measuring the output frequency of a source of recurrent pulses, comprising: a metering circuit connected to receive the pulses of said source; a normally closed gate in said circuit; programming means connected to said gate for repeatedly opening same to establish a measuring interval; a pulse counter in said circuit connected to said source by way of said gate, saId programming means being connected to said counter for setting same to zero before each measuring interval, said programming means emitting an enabling signal following the emission of said updating signal and the zero-setting of said counter; a buffer register in said circuit connected to said counter and loadable by the latter in response to an updating signal emitted by said programming means between measuring intervals; digital indicator means connected to said register for displaying the contents thereof; coincidence means responsive to the occurrence of a pulse from said source in the presence of said enabling signal for triggering programming means into generation of an unblocking signal for said gate; and delay means for said unblocking signal between said programming means and said gate for retarding the beginning of a measuring interval by a fraction of a cycle of any pulse frequency to be measured.
Claim 7
Independent Claim
207 words
A system for measuring the output frequency of a source of recurrent pulses, comprising: a metering circuit connected to receive the pulses of said source; a normally closed gate in said circuit; programming means connected to said gate for repeatedly opening same to establish a measuring interval; a pulse counter in said circuit connected to said source by way of said gate, saId programming means being connected to said counter for setting same to zero before each measuring interval, said programming means emitting an enabling signal following the emission of said updating signal and the zero-setting of said counter; a buffer register in said circuit connected to said counter and loadable by the latter in response to an updating signal emitted by said programming means between measuring intervals; digital indicator means connected to said register for displaying the contents thereof; coincidence means responsive to the occurrence of a pulse from said source in the presence of said enabling signal for triggering programming means into generation of an unblocking signal for said gate; and delay means for said unblocking signal between said programming means and said gate for retarding the beginning of a measuring interval by a fraction of a cycle of any pulse frequency to be measured.
Claim 8
Dependent Claim
91 words
A system as defined in claim 4, further comprising timing means connected to said programming means and to said source for determining the duration of a period between the end of a preceding measuring interval and an immediately following pulse from said source, and control means responsive to said timing means for extending the next-following measuring interval beyond the end of said unblocking signal by a length of time depending on said duration to terminate said next-following interval a fraction of a pulse cycle after the counting of the last pulse.
Claim 9
Dependent Claim
37 words
A system as defined in claim 5 wherein said control means comprises storage means for a voltage proportional to said duration and generator means responsive to said voltage for producing a supplemental unblocking signal for said gate.
Claim 10
Dependent Claim
55 words
A system as defined in claim 6, further comprising analog-type frequency-discriminating means connected to said source; said delay means and said generator means having control inputs connected to said frequency-discriminating means for varying the retardation of the beginning of a measuring interval and the extension thereof in dependence upon the recurrence rate of said pulses.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |