Patent US4139802A successfully refreshed from Google Patents.
US4139802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-responsive electric switch
Assignee: FABRIQUE D HORLOGERIE LA VEDETTE SA
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Filing: 1977-06-21
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Granted: 1979-02-13
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Expires: 1997-06-21
Abstract
Abstract The disclosure is of a light-responsive electric switch which is characterized in that it is constituted mainly by a photoresistive cell inserted in a voltage-divider bridge of which the voltage variations, as functions of the illumination, control a standard integrated circuit comprising four NAND gates which, through the intermediary of a transistor, actuate a triac controlling the illumination circuit.
Inventors
- 👤 Guy Dubot
- 👤 Jacques Lemercier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:09
CPC Classifications
H; H05; H05B; H05B47/00; H05B47/10; H05B47/105; H05B47/11; Y; Y02; Y02B; Y02B20/00; Y02B20/40
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
92 words
A twilight-responsive switch, comprising an electronic circuit comprising a voltage divider including a fixed resistor, a potentiometer allowing adjustment of the sensitivity, and a variable resistor constituting a photoresistance, a standard integrated circuit of the CMOS technology provided with four NAND gates, a delay circuit formed by two capacitors and a resistor, and an output stage comprising a transistor in the collector circuit of which is connected the gate of a triac which controls, as a function of the illumination of the photoresistance, the lighting up or the extinction of a lamp.
Claim 2
Dependent Claim
92 words
A twilight-responsive switch, comprising an electronic circuit comprising a voltage divider including a fixed resistor, a potentiometer allowing adjustment of the sensitivity, and a variable resistor constituting a photoresistance, a standard integrated circuit of the CMOS technology provided with four NAND gates, a delay circuit formed by two capacitors and a resistor, and an output stage comprising a transistor in the collector circuit of which is connected the gate of a triac which controls, as a function of the illumination of the photoresistance, the lighting up or the extinction of a lamp.
Claim 3
Dependent Claim
43 words
A switch as claimed in claim 1, adapted to be supplied with alternating current the electronic circuit having at the input a resistor, a diode, and a smoothing capacitor, as well as a voltage regulator composed of a resistor and a Zener diode.
Claim 4
Dependent Claim
47 words
A switch as claimed in claim 1, and two polarised capacitors connected in the circuit in such a manner that their respective leakage currents are compensated and permit the achievement of a delay in the connection and the disconnection of the lamp with a very small differential.
Claim 5
Dependent Claim
55 words
A switch as claimed in claim 1, and an adjustable resistor between the input to the first gate and the output from the second gate of the integrated circuit, which allows compensation for the influence of the illumination from the lamp upon the photoresistance when this latter is placed in the proximity of the lamp.
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) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |