Patent US3914712A successfully refreshed from Google Patents.
US3914712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage controlled oscillator having frequency varying inversely with control voltage
Assignee: National Aeronautics and Space Administration
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Filing: 1974-09-30
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Granted: 1975-10-21
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Expires: 1994-09-30
Abstract
Abstract A voltage controlled oscillator wherein the frequency of the oscillator varies linearly with the reciprocal of the input voltage. It employs two cascaded operational amplifiers wherein the first functions as a comparator and the second one functions as an integrator, the output of the latter being coupled back to a non-inverting input of the former.
Inventors
- 👤 James R Currie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:56
CPC Classifications
H; H03; H03K; H03K7/00; H03K7/06; H03K4/00; H03K4/06; H03K4/066; H04; H04L; H04L27/00; H04L27/10; H04L27/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
141 words
A voltage controlled oscillator Comprising: a first stage comprising: a first operational amplifier and a clamping transistor, the output of said first operational amplifier being connected to the input of said transistor, and the output of said transistor being connected to the inverting input of said first operational amplifier; a second stage comprising: a second operational amplifier, integrating means, a timing resistor, said integrating means being connected between the output of said second operational amplifier and the inverting input of said second operational amplifier, said timing resistor being connected between the output of said first operational amplifier and the inverting input of said second operational amplifier, and the output of said second operational amplifier being connected to the non-inverting input of said first operational amplifier; and means for connecting a control voltage to the inverting input of said first operational amplifier.
Claim 2
Dependent Claim
141 words
A voltage controlled oscillator Comprising: a first stage comprising: a first operational amplifier and a clamping transistor, the output of said first operational amplifier being connected to the input of said transistor, and the output of said transistor being connected to the inverting input of said first operational amplifier; a second stage comprising: a second operational amplifier, integrating means, a timing resistor, said integrating means being connected between the output of said second operational amplifier and the inverting input of said second operational amplifier, said timing resistor being connected between the output of said first operational amplifier and the inverting input of said second operational amplifier, and the output of said second operational amplifier being connected to the non-inverting input of said first operational amplifier; and means for connecting a control voltage to the inverting input of said first operational amplifier.
Claim 3
Dependent Claim
17 words
A voltage controlled oscillator as set forth in claim 1 wherein said integrating means comprises a capacitor.
Claim 4
Dependent Claim
63 words
A voltage controlled oscillator as set forth in claim 1 wherein said means for supplying a control voltage input to said operational amplifier comprises a positive voltage source, the collector of said transistor is connected to said inverting input of said first operational amplifier and said first stage further includes a diode connected in reverse polarity across the base-emitter circuit of said transistor.
Claim 5
Dependent Claim
30 words
A voltage controlled oscillator as set forth in claim 2 further comprising current limiting resistance connected between the output of said first operational amplifier and the input of said transistor.
References Cited (Backward Citations)
US3656066A
Cited
US3760248A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |