US3555263A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid-state analog computing device for controlling a photo-resistor in non-linear relationship to input
Assignee: Controle Bailey SA
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Filing: 1967-04-26
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Granted: 1971-01-12
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Expires: 1987-04-26
Abstract
Abstract A solid-state device for generating an impedance varying in functional relation to a variable input signal.
Inventors
- 👤 Jean C Lejon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:14
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/16; G06G7/163
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
166 words
A device for effecting variations in the resistance of a photoresistor in predetermined nonlinear functional relationship to an analogue input signal, comprising: an amplifier having a pair of input terminals between which the analogue input signal is applied; a light source connected to the output of said amplifier; a photoconductive cell illuminated by said light source including a first photoresistor and a second photoresistor, the resistance of each of said photoresistors varying in substantially linear relationship with the intensity of illumination by said light source, said photoresistors being equally illuminated by said light source; circuit means including said first variable photoresistor to develop a nonlinear feedback signal, said feedback signal being applied between the input terminals of said amplifier in series opposing relationship with respect to the analogue input signal to form an error signal across the input terminals of said amplifier to control the intensity of said light source and thereby the resistance of said second photoresistor in predetermined nonlinear relationship with said input signal.
Claim 2
Independent Claim
166 words
A device for effecting variations in the resistance of a photoresistor in predetermined nonlinear functional relationship to an analogue input signal, comprising: an amplifier having a pair of input terminals between which the analogue input signal is applied; a light source connected to the output of said amplifier; a photoconductive cell illuminated by said light source including a first photoresistor and a second photoresistor, the resistance of each of said photoresistors varying in substantially linear relationship with the intensity of illumination by said light source, said photoresistors being equally illuminated by said light source; circuit means including said first variable photoresistor to develop a nonlinear feedback signal, said feedback signal being applied between the input terminals of said amplifier in series opposing relationship with respect to the analogue input signal to form an error signal across the input terminals of said amplifier to control the intensity of said light source and thereby the resistance of said second photoresistor in predetermined nonlinear relationship with said input signal.
Claim 3
Dependent Claim
63 words
A device according to claim 1 wherein said first photoresistor has a variable resistance R1 according to the equation R1 g(V1''), said nonlinear feedback signal V1'' varies according to the equation V1'' f(R1) and said second photoresistor has a variable resistance R2 according to equation R2 g(V1), where V1 is said analogue input signal and g is the inverse function of f .
Claim 4
Dependent Claim
23 words
A device according to claim 2 wherein said circuit means for electrically energizing said first variable photoresistor develops an exponential feedback signal V1''.
References Cited (Backward Citations)
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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) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |