US3597652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for maintaining the temperature and operating a calibrated lamp in a constant resistance mode
Assignee: Revvity Inc
•
Filing: 1969-01-14
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Granted: 1971-08-03
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Expires: 1989-01-14
Abstract
Abstract The resistance of an incandescent lamp filament, subject to ambient variations, is determined by sensing the current and voltage of the lamp filament. Since the resistance is a known function of the temperature of the filament, changes in the temperature of the filament are sensed to provide an output correction signal to a power supply which adjusts the input parameters of the lamp to maintain filament temperature constant.
Inventors
- 👤 Percival T Gates Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:12
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/2401; G05D23/2451; G05D23/2456; H; H05; H05B; H05B39/00; H05B39/04; H05B39/041; H05B39/044; Y; Y02; Y02B; Y02B20/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
Apparatus for maintaining the temperature of a lamp filament constant, comprising: a source of potential connected to the filament for providing operating parameters of a given ratio thereto; a plurality of sensing means connected in series and in parallel with the filament; each sensing means detecting an operating parameter of the filament, and each deriving respective signal voltages therefrom representative of the sensed parameter; means connecting the respective signal voltages to detecting means for sensing and for deriving an error signal in response to changes in the ratio of sensed parameters; and means connecting the error signal to the source of potential to vary the operating parameters and maintain the ratio constant.
Claim 2
Dependent Claim
112 words
Apparatus for maintaining the temperature of a lamp filament constant, comprising: a source of potential connected to the filament for providing operating parameters of a given ratio thereto; a plurality of sensing means connected in series and in parallel with the filament; each sensing means detecting an operating parameter of the filament, and each deriving respective signal voltages therefrom representative of the sensed parameter; means connecting the respective signal voltages to detecting means for sensing and for deriving an error signal in response to changes in the ratio of sensed parameters; and means connecting the error signal to the source of potential to vary the operating parameters and maintain the ratio constant.
Claim 3
Dependent Claim
26 words
The apparatus of claim 1, wherein: the potential connected to the lamp filament is direct current; and the operating parameters are filament voltage and filament current.
Claim 4
Dependent Claim
59 words
The apparatus of claim 2, wherein; the means sensing the voltage operating parameter and the means sensing the current operating parameter are a pair of magnetic amplifier control windings; and output windings coupled to the control windings for generating a signal voltage representative of changes in the ratio of the sensed voltage and sensed current of the lamp filament.
Claim 5
Dependent Claim
43 words
The apparatus of claim 3, further comprising: a constant current power supply providing the voltage and current parameters; and a series passing stage in series with the power supply output for detecting the changes in the ratio of sensed voltage to sensed current.
Claim 6
Dependent Claim
26 words
The apparatus of claim 1, wherein: the potential connected to the lamp filament is alternating current; and the operating parameters are filament voltage and filament current.
Claim 7
Dependent Claim
60 words
The apparatus of claim 5, wherein: the means sensing the voltage operating parameter and the means sensing the current operating parameter are a pair of electromagnetically coupled transformer windings; and an output winding coupled to the pair of windings for generating a signal voltage representative of the ratio of the sensed voltage to the sensed current of the lamp filament.
Claim 8
Dependent Claim
52 words
The apparatus of claim 6, further comprising: A variable output autotransformer, the input of which is connected to the source of alternating current the output of which is connected to one pair of windings; and drive means connected to the output of the autotransformer for varying the operating parameters to the transformer.
Claim 9
Dependent Claim
77 words
THe apparatus of claim 7, further comprising: a phase sensitive detector connected to the output winding: a source of reference phase voltage connected to the phase detector; the phase detector combining the signal voltage and the reference phase voltage to derive an error signal responsive to the change in the ratio of sensed parameters; and means connecting the output of the phase sensitive detector to the drive means to vary the operating parameters of the lamp filament.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |