Patent US3992680A successfully refreshed from Google Patents.
US3992680A
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Precision test frequency generator
Assignee: Fischer and Porter Co
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Filing: 1975-07-30
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Granted: 1976-11-16
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Expires: 1995-07-30
Abstract
Abstract A precision test frequency generator capable of selectively providing a sinusoidal output wave within a frequency range simulating the output of a flowmeter yielding a sinusoidal signal whose frequency is proportional to flow rate, the signal having a noise component superimposed thereon. The generator is constituted by a stable high-frequency standard coupled to a selectable output counter providing intermediate-frequency pulses whose repetition rate is a sub-multiple of the high-frequency standard and a predetermined multiple of the desired output frequency of the generator. The pulses are converted into a triangular wave whose frequency corresponds to the desired output frequency, the triangular wave having a staircase formation whose number of steps is determined by the multiple. The triangular wave is converted into a sinusoidal wave of the same frequency with a staircase modulation component simulating the flowmeter output signal.
Inventors
- 👤 Peter J. Herzl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:38
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/02; H03K4/026
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
190 words
A precision test generator producing sinusoidal output waves in a predetermined range to simulate the output of an instrument yielding a sinusoidal signal within said range, said sinusoidal signal having a noise component superimposed thereon, said test generator comprising: A. a stable-frequency standard having a predetermined high-frequency; B. means coupled to said standard to divide the frequency thereof to produce intermediate frequency pulses whose repetition rate is a selected sub-multiple of said high frequency and a predetermined multiple of the desired output frequency of the test generator within said range, said divider means being constituted by a multi-stage counter provided with a multi-contact selector switch whose contacts are connected to the respective stages of the counter to derive pulses of the desired repetition rate; C. a triangle generator responsive to said pulses to produce a triangular wave whose frequency corresponds to the desired output frequency, said triangular wave having a staircase formation whose number of steps is determined by said multiple; and D. means coupled to said triangle generator to transform said triangular wave into a sinusoidal output wave of the same frequency with a staircase component simulating said signal.
Claim 2
Dependent Claim
190 words
A precision test generator producing sinusoidal output waves in a predetermined range to simulate the output of an instrument yielding a sinusoidal signal within said range, said sinusoidal signal having a noise component superimposed thereon, said test generator comprising: A. a stable-frequency standard having a predetermined high-frequency; B. means coupled to said standard to divide the frequency thereof to produce intermediate frequency pulses whose repetition rate is a selected sub-multiple of said high frequency and a predetermined multiple of the desired output frequency of the test generator within said range, said divider means being constituted by a multi-stage counter provided with a multi-contact selector switch whose contacts are connected to the respective stages of the counter to derive pulses of the desired repetition rate; C. a triangle generator responsive to said pulses to produce a triangular wave whose frequency corresponds to the desired output frequency, said triangular wave having a staircase formation whose number of steps is determined by said multiple; and D. means coupled to said triangle generator to transform said triangular wave into a sinusoidal output wave of the same frequency with a staircase component simulating said signal.
Claim 3
Dependent Claim
16 words
A test generator as set forth in claim 1, wherein said standard is a crystal-controlled oscillator.
Claim 4
Dependent Claim
16 words
A test generator as set forth in claim 1, wherein said high-frequency is about 30,000 Hz.
Claim 5
Dependent Claim
25 words
A test generator as set forth in claim 3, wherein said test generator produces output frequencies in the range of 1 to about 2000 Hz.
Claim 6
Dependent Claim
30 words
A test generator as set forth in claim 1, further including an interface network coupled to said transforming means to interface said sinusoidal output wave with particular forms of flowmeters.
Claim 7
Dependent Claim
66 words
A test generator as set forth in claim 1, wherein said triangle generator includes a ladder network of resistors having different values, and means including a counter responsive to said pulses to selectively connect said resistors to a voltage source to produce an output voltage which progressively rises to create the ascending steps of the staircase and then progressively falls to create the descending steps thereof.
Claim 8
Dependent Claim
30 words
A test generator as set forth in claim 6, wherein said means for selectively connecting the resistors to the source is constituted by gate logic units associated with said counter.
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) | 1979-11-16 | 1980-05-17 | 1980-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-16 | 1984-05-17 | 1984-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-16 | 1988-05-17 | 1988-11-16 | $7700.00 | Window Closed / Lapsed |