US3580683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Computing colorimeter
Assignee: Photovolt Corp
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Filing: 1969-01-14
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Granted: 1971-05-25
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Expires: 1989-01-14
Abstract
Abstract A colorimeter with a computing circuit by which the concentration of a sample fluid is linearly indicated. Light transmitted through a sample vial of the fluid is directed upon a photosensing device which provides an electrical signal corresponding to the intensity of a transmitted light. The electrical signal from the photosensing device is applied to a computing circuit which transforms the applied electrical signal into one linearly related to the concentration of the fluid under investigation. The output of the computing circuit deflects a current indicating device so that the deflection of this device is proportional to the concentration of the fluid.
Inventors
- 👤 Herbert Schulkind
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:35
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/27
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
26 words
A colorimeter as defined in claim 1, wherein said first and second transistors are positioned so as to comprise a pair at substantially the same temperature.
Claim 2
Dependent Claim
97 words
A colorimeter as defined in claim 1, wherein said color filter means has a plurality of color filters, and further including a current source for said light source; and a second comparator circuit connected to said current source and to said source of reference voltage for controlling the latter to cause the voltage supplied to said light source and to said noninverting input to vary in dependence on which one of said color filters is in the path of said beam of light, so that zero setting of the colorimeter is independent of the color filter used.
Claim 3
Dependent Claim
86 words
A colorimeter as defined in claim 3, further including a direct current source, and wherein said direct current source includes at least two series connected first and second transistors forming a series path circuit, the collectors of said series connected first and second transistors being connected to the output of said direct current source, the emitter of said first transistor being connected to the base of said second transistor and the emitter of said second transistor being connected to said output of the direct current source.
Claim 4
Dependent Claim
227 words
A colorimeter as defined in claim 4, further including a source of coarse preregulated voltage, the output of said source of coarse preregulated voltage being connected to the input of said source of reference voltage; as many resistors as there are said color filters connected to one side of the output of said source of reference voltage, and wherein said second comparator circuit comprises first and second transistors, a common resistor connecting the emitters thereof to one side of said light source, the base of said second transistor being connected to the other side of said light source, the collector of said second transistor of said second comparator circuit being connected to the base of said first transistor of said current source, a resistor connecting together the collectors of said first and second transistors of said second comparator circuit and also connecting the collector of said second transistor to the output of said source of preregulated voltage; and a switch having a movable contact for connecting the base of said first transistor of said second comparator circuit in turn to each of said resistors connected to said one side of the output of said source of reference voltage for enabling, in dependence on the filter in said path of the light beam, variation of the voltage furnished to said noninverting input by said source of reference voltage.
Claim 5
Dependent Claim
51 words
A colorimeter as defined in claim 5, including a potentiometer connected between the other side of said output of the source of reference voltage and said movable contact of said switch, and a wiper comprised by said potentiometer connected to said base of said first transistor of said second comparator circuit.
Claim 6
Dependent Claim
94 words
A colorimeter as defined in claim 2, including the same number, greater than one, of first and second transistors, said first transistors and said second transistors respectively being directly coupled in series, corresponding ones of said first and second transistors being positioned so as to comprise pairs at substantially the same temperature, and the control electrode of each of said first transistors being connected to a main electrode of the respective first transistor and the control electrode of each of said second transistors being connected to a main electrode of the respective second transistor.
Claim 7
Dependent Claim
38 words
A colorimeter as defined in claim 1, further including a current source for said light source; and a second comparator circuit for comparing the voltage across said light source with said reference voltage to regulate said current source.
Claim 8
Dependent Claim
83 words
A colorimeter as defined in claim 8, further including a direct current source, and wherein said current source includes at least two series connected first and second transistors forming a series path circuit, the collectors of said first and second transistors being connected to the output of said direct current source, the emitter of said first transistor being connected to the base of said second transistor and the emitter of said second transistor being connected to said output of the direct current source.
Claim 9
Dependent Claim
236 words
A colorimeter as defined in claim 9, wherein said color filter means has a plurality of color filters, And further including a source of coarse preregulated voltage, the output of said source of coarse preregulated voltage being connected to the input of said source of reference voltage; as many resistors as there are said color filters connected to one side of the output of said source of reference voltage, and wherein said second comparator circuit comprises first and second transistors, a common resistor connecting the emitters thereof to one side of said light source, the base of said second transistor being connected to the other side of said light source, the collector of said second transistor of said comparator circuit being connected to the base of said first transistor of said current source, a resistor connecting together the collectors of said first and second transistors of said comparator circuit and also connecting the collector of said second transistor of said comparator circuit to the output of said source of preregulated voltage; and a switch having a movable contact for connecting the base of said first transistor of said comparator circuit in turn to each of said resistors connected to said one side of the output of said source of reference voltage for enabling, in dependence on the filter in said path of the light beam, variation of the output voltage of said source of reference voltage.
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |