US3655987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for noise reduction in output of photoemissive cell comprising periodically discharged integrator capacitor
Assignee: Vickers Ltd
•
Filing: 1970-05-26
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Granted: 1972-04-11
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Expires: 1990-05-26
Abstract
Abstract An electrical circuit including a photoemissive cell and an integrator capacitor which receives current from the cell and which is repeatedly discharged, the output being amplified to produce an amplified representation of the photocurrent of the cell with reduced noise.
Inventors
- 👤 David Hinds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:23
CPC Classifications
G; G11; G11C; G11C27/00; G11C27/02; G11C27/024; G11C27/026; G01; G01J; G01J1/00; G01J1/42; G01J1/44; G01J1/46; H; H03; H03F; H03F3/00; H03F3/38; H03F3/387
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
64 words
An electrical circuit comprising a. a photoemissive cell, b. amplification means for amplifying the output of the cell, c. an integrator capacitor connected to the output of the cell and to the amplification means, and d. switching means for repeatedly discharging the integrator capacitor at predetermined equal time intervals, whereby to reduce the effect of noise in the signal fed to the amplification means.
Claim 2
Dependent Claim
64 words
An electrical circuit comprising a. a photoemissive cell, b. amplification means for amplifying the output of the cell, c. an integrator capacitor connected to the output of the cell and to the amplification means, and d. switching means for repeatedly discharging the integrator capacitor at predetermined equal time intervals, whereby to reduce the effect of noise in the signal fed to the amplification means.
Claim 3
Dependent Claim
16 words
An electrical circuit as claimed in claim 1, wherein the amplification means comprises a D.C. amplifier.
Claim 4
Dependent Claim
27 words
An electrical circuit as claimed in claim 1, wherein the amplification means comprises an A.C. coupled amplifier, and a D.C. restorer is connected to the A.C. amplifier.
Claim 5
Dependent Claim
18 words
An electrical circuit as claimed in claim 3, wherein the D.C. restorer comprises a shunt synchronous demodulator transistor.
Claim 6
Dependent Claim
32 words
An electrical circuit as claimed in claim 4, wherein the switching means comprises a transistor connected to a clock pulse generator operative to feed pulses to the transistor at fixed time intervals.
Claim 7
Dependent Claim
23 words
An electrical circuit as claimed in claim 1, wherein the output of the amplificatioN means is connected to a sample and hold device.
Claim 8
Independent Claim
38 words
A method of reducing the effect of noise in a photoemissive cell current including the steps of feeding the current to an integrator capacitor, repeatedly discharging the capacitor at predetermined equal time intervals and amplifying the signal produced.
Claim 9
Independent Claim
38 words
A method of reducing the effect of noise in a photoemissive cell current including the steps of feeding the current to an integrator capacitor, repeatedly discharging the capacitor at predetermined equal time intervals and amplifying the signal produced.
Claim 10
Dependent Claim
17 words
A method as claimed in claim 7, wherein the integrator capacitor is discharged at fixed time intervals.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 7, wherein the amplified signal is fed into a sample and hold device.
References Cited (Backward Citations)
US1973512A
Cited
US2386320A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |