Patent US3984676A successfully refreshed from Google Patents.
US3984676A
Expired / Lapsed
US
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Light-measuring apparatus with lamp indicator for determining balance of a measuring bridge
Assignee: Durst Group AG
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Filing: 1974-10-18
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Granted: 1976-10-05
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Expires: 1994-10-18
Abstract
Abstract This invention relates to a light-measuring apparatus wherein a photoelectric element is arranged in a leg of a measuring bridge, the output voltage of said element controlling the brightness of two signal lamps.
Inventors
- 👤 Siegfried Barbieri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:22
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/44; G03; G03B; G03B17/00; G03B17/18; G03B17/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
A light-measuring apparatus comprising a measuring bridge, a photoelectric element is arranged in a leg of the measuring bridge, the voltage obtained from the measuring bridge controlling the brightness of two signal lamps arranged in series parallel to a power source feeding the measuring bridge, characterized in that the outputs of the measuring bridge are connected with the inputs of a sum-and-difference amplifier, the output of the sum-and-difference amplifier being connected to a junction between the two signal lamps, the amplification factor of the sum-and-difference amplifier being arranged to be high enough that a simultaneous illumination of both signal lamps connected with the output of the sum-and-difference amplifier only occurs within a predetermined error range allowable for the balancing of the measuring bridge.
Claim 2
Dependent Claim
123 words
A light-measuring apparatus comprising a measuring bridge, a photoelectric element is arranged in a leg of the measuring bridge, the voltage obtained from the measuring bridge controlling the brightness of two signal lamps arranged in series parallel to a power source feeding the measuring bridge, characterized in that the outputs of the measuring bridge are connected with the inputs of a sum-and-difference amplifier, the output of the sum-and-difference amplifier being connected to a junction between the two signal lamps, the amplification factor of the sum-and-difference amplifier being arranged to be high enough that a simultaneous illumination of both signal lamps connected with the output of the sum-and-difference amplifier only occurs within a predetermined error range allowable for the balancing of the measuring bridge.
Claim 3
Dependent Claim
24 words
The light-measuring apparatus of claim 1, characterized in that signal lamps are employed, which have an illuminating effect only beyond a certain voltage threshold.
Claim 4
Dependent Claim
31 words
The light-measuring apparatus of claim 2, characterized in that the value of the voltage threshold is equal to or higher than the value of the residual voltage of the sum-and-difference amplifier.
Claim 5
Dependent Claim
17 words
The light-measuring apparatus of claimm 2, characterized in that luminous diodes are employed as the signal lamps.
Claim 6
Dependent Claim
17 words
The light-measuring apparatus of claim 2, characterized in that fluorescent lamps are employed as the signal lamps.
References Cited (Backward Citations)
US3530378A
Cited
US3794430A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-05 | 1980-04-05 | 1980-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-05 | 1984-04-05 | 1984-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-05 | 1988-04-05 | 1988-10-05 | $7700.00 | Window Closed / Lapsed |