US3980903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical-electronic relay
Assignee: Thales SA
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Filing: 1975-03-25
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Granted: 1976-09-14
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Expires: 1995-03-25
Abstract
Abstract A relay controlled by light radiation ensuring electrical insulation between the control circuit and the controlled circuit, comprising a transistor T connected across terminals of the circuit (S,R) and controlled by a signal coming from the phototransistor (PT). The protection of this phototransistor against the voltage differences appearing across the terminals (1) (1'), depending upon whether the circuit is open or closed, is provided by a constant current supply circuit incorporating a transistor (T') controlled by a signal created across the terminals of a resistor (22).
Inventors
- 👤 Jean Jamee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:48
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/941
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
173 words
An optical-electronic relay comprising a main transistor (T), having three electrodes, respectively an emitter, a base and a collector, which, in an electrical circuit, by opening or closing thereof, through the action of an electrical signal applied to its base, enables a current to flow, or interrupts such current, said circuit having two terminals, the first connected to the emitter and the second, across a resistor, to the collector of said transistor, and comprising at least one electrical energy source (S) and a load (R) connected in series, said electrical signal being created, under the action of an electromagnetic radiation source (13), by a phototransistor (PT) arranged opposite said source, wherein said phototransistor having its collector connected to the common point of a divider bridge connected between said two terminals, and constituted by two resistive elements arranged in series, the resistance of at least one of said elements being variable, and being controlled by said current, so achieving safely, in respect of said opening and closing operations, a constant current through the phototransistor.
Claim 2
Dependent Claim
173 words
An optical-electronic relay comprising a main transistor (T), having three electrodes, respectively an emitter, a base and a collector, which, in an electrical circuit, by opening or closing thereof, through the action of an electrical signal applied to its base, enables a current to flow, or interrupts such current, said circuit having two terminals, the first connected to the emitter and the second, across a resistor, to the collector of said transistor, and comprising at least one electrical energy source (S) and a load (R) connected in series, said electrical signal being created, under the action of an electromagnetic radiation source (13), by a phototransistor (PT) arranged opposite said source, wherein said phototransistor having its collector connected to the common point of a divider bridge connected between said two terminals, and constituted by two resistive elements arranged in series, the resistance of at least one of said elements being variable, and being controlled by said current, so achieving safely, in respect of said opening and closing operations, a constant current through the phototransistor.
Claim 3
Dependent Claim
77 words
An optical-electronic relay as claim in claim 1, wherein said element exhibiting variable resistance is constituted by a second resistor and a second transistor connected in parallel, the emitter of said second transistor, being connected across an emitter resistor to that end of said second resistor which is connected to said second terminal, the collector being connected to the other end of said second resistor, and the base being connected to the collector of the main transistor.
Claim 4
Dependent Claim
23 words
An optical-electronic relay as claimed in claim 2, wherein a diode is connected in parallel across said collector resistor of the main transistor.
Claim 5
Dependent Claim
21 words
An optical-electronic relay as claimed in claim 2, wherein the other of said variable-resistance elements is constituted by a zener diode.
Claim 6
Dependent Claim
20 words
An optical-electronic relay as claimed in claim 1, wherein the wavelength of said radiation is located in the visible range.
Claim 7
Dependent Claim
20 words
An optical-electronic relay as claimed in claim 1, wherein the wavelength of said radiation is located in the infra-red range.
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) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |