US3734632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current compensated detection circuits for photovoltaic cells
Assignee: Minolta Co Ltd
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Filing: 1971-10-29
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Granted: 1973-05-22
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Expires: 1991-10-29
Abstract
Abstract A circuit for detecting current generated by a light transducer such as a photovoltaic cell includes at least one P-N junction for biasing a transistor to compensate for the voltage drop of the base emitter junction thereof and includes feedback between the collector of the transistor and the biasing junction to compensate for temperature changes and changes in the amplification factor of the transistor whereby the linearity of the light transducer output is maintained.
Inventors
- 👤 M Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:33
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/04; H03F3/08; Y; Y10; Y10S; Y10S136/00; Y10S136/291
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
93 words
A light detecting circuit comprising: means for generating current in response to light incident thereon; a transistor having a base emitter junction connected to one terminal of said means for generating current; biasing means including a P-N junction connected between said base emitter junction to oppose the voltage drop thereof and connected to the other terminal of said means for generating current; and feedback means connected between the collector of said transistor and said biasing means for providing said biasing means with an electric current proportional to the collector current of said transistor.
Claim 2
Dependent Claim
93 words
A light detecting circuit comprising: means for generating current in response to light incident thereon; a transistor having a base emitter junction connected to one terminal of said means for generating current; biasing means including a P-N junction connected between said base emitter junction to oppose the voltage drop thereof and connected to the other terminal of said means for generating current; and feedback means connected between the collector of said transistor and said biasing means for providing said biasing means with an electric current proportional to the collector current of said transistor.
Claim 3
Dependent Claim
177 words
A light measuring circuit comprising: means for generating current in response to light incident thereon; a first transistor; a first biasing means including a P-N junction connected between the base and the emitter of said first transistor through said means for generating current; a second transistor having a collector connected to said first biasing means; a second biasing means including a P-N junction connected between the vase and the emitter of said second transistor and connected to the collector of said first transistor so that the collector current thereof flows through the P-N junction of said second biasing means; an ammeter connected to the output of said first transistor; and said first and second transistors and said P-N junction are selected in accordance with the following: C2/C1 C4/C3 wherein C1, C2, C3, C4 are respective constants for the base-emitter junction of said first transistor, the P-N junction of said first biasing means, the base-emitter junction of said second transistor and the P-N junction of said second biasing means, and i Cn.erV (n 1, 2, 3 or 4)
Claim 4
Dependent Claim
177 words
A light measuring circuit comprising: means for generating current in response to light incident thereon; a first transistor; a first biasing means including a P-N junction connected between the base and the emitter of said first transistor through said means for generating current; a second transistor having a collector connected to said first biasing means; a second biasing means including a P-N junction connected between the vase and the emitter of said second transistor and connected to the collector of said first transistor so that the collector current thereof flows through the P-N junction of said second biasing means; an ammeter connected to the output of said first transistor; and said first and second transistors and said P-N junction are selected in accordance with the following: C2/C1 C4/C3 wherein C1, C2, C3, C4 are respective constants for the base-emitter junction of said first transistor, the P-N junction of said first biasing means, the base-emitter junction of said second transistor and the P-N junction of said second biasing means, and i Cn.erV (n 1, 2, 3 or 4)
Claim 5
Dependent Claim
30 words
A light measuring circuit as set forth in claim 2, wherein said means for generating current is connected between the base of said first transistor and said first biasing means.
Claim 6
Dependent Claim
27 words
A light measuring circuit as set forth in claim 3, wherein said ammeter is connected between the collector of said first transistor and said second biasing means.
Claim 7
Dependent Claim
53 words
A light measuring circuit as set forth in claim 2, wherein said first biasing means is a third transistor having an interconnected base and a collector and connected to the base of said first transistor and the collector of said second transistor, and an emitter connected to the emitter of said first transistor.
Claim 8
Dependent Claim
46 words
A light measuring circuit as set forth in claim 5, wherein said second biasing means is a fourth transistor having an interconnected base and a collector and connected to the base of said second transistor, and a emitter connected to the emiTter of said second transistor.
Claim 9
Dependent Claim
25 words
A light measuring circuit as set forth in claim 2, wherein said means for generating current is connected to the emitter of said first transistor.
Claim 10
Dependent Claim
44 words
A light measuring circuit as set forth in claim 7, wherein said means for generating current, said first transistor and said second biasing means are connected in series with each other, and a power source is connected across the series connection via said ammeter.
Claim 11
Dependent Claim
24 words
A light measuring circuit as set forth in claim 2, further comprising a capacitor shunted across the P-N junction of said second biasing means.
References Cited (Backward Citations)
US3424908A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |