US4016451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High pressure discharge lamp dimming circuit utilizing variable duty-cycle photocoupler
Assignee: Westinghouse Electric Corp
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Filing: 1975-03-13
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Granted: 1977-04-05
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Expires: 1995-03-13
Abstract
Abstract The low-cost lighting control apparatus for high-pressure discharge lamps utilizing an ON-OFF photocoupler to provide isolation between the relatively high voltage AC supplied to the lamp load and the relatively low voltage DC control circuitry. Preferably, the apparatus is current-feedback stabilized utilizing a feedback resistor.
Inventors
- 👤 Joseph C. Engel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:01
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/36; H05B41/38; H05B41/39; H05B41/392; H05B41/3921; H05B41/3927; H05B41/3928; Y; Y02; Y02B; Y02B20/00; Y10; Y10S; Y10S315/00; Y10S315/04; Y10S315/05
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
217 words
A lighting control apparatus to provide variable intensity light from a high-pressure discharge lamp load utilizing a photocoupler actuated by a variable duty-cycle circuit which varies the ON time of an LED in response to an externally generated electrical demand signal, said apparatus comprising: a. power control means having a signal input, a power input, and a power output, said power input being adapted to be connected to a source of AC power; b. ballasting means having an input and an output, said ballasting means input being connected to said power control means output; c. a discharge lamp load, said discharge lamp load being connected to the output of said ballasting means; d. variable duty-cycle circuit means having an input and an output, said demand signal adapted to be applied to the input of said variable duty-cycle circuit means; and e. LED-photoresistor means for providing electrical isolation between said applied demand signal and said power control means, said LED-photoresistor means having an input and an output, said LED-photoresistor means input being connected to said variable duty-cycle circuit means output to cause said LED to be ON a percentage of the time which is proportional to the value of said demand signal, and said LED-photoresistor means output being connected to said signal input of said power control means.
Claim 2
Dependent Claim
217 words
A lighting control apparatus to provide variable intensity light from a high-pressure discharge lamp load utilizing a photocoupler actuated by a variable duty-cycle circuit which varies the ON time of an LED in response to an externally generated electrical demand signal, said apparatus comprising: a. power control means having a signal input, a power input, and a power output, said power input being adapted to be connected to a source of AC power; b. ballasting means having an input and an output, said ballasting means input being connected to said power control means output; c. a discharge lamp load, said discharge lamp load being connected to the output of said ballasting means; d. variable duty-cycle circuit means having an input and an output, said demand signal adapted to be applied to the input of said variable duty-cycle circuit means; and e. LED-photoresistor means for providing electrical isolation between said applied demand signal and said power control means, said LED-photoresistor means having an input and an output, said LED-photoresistor means input being connected to said variable duty-cycle circuit means output to cause said LED to be ON a percentage of the time which is proportional to the value of said demand signal, and said LED-photoresistor means output being connected to said signal input of said power control means.
Claim 3
Dependent Claim
51 words
The apparatus of claim 1, wherein a current sensing means is connected in series with said power control means for developing a current feedback signal and wherein said power control means has a feedback input and said current feedback signal is connected to said feedback input of said power control means.
Claim 4
Dependent Claim
21 words
The apparatus of claim 2, wherein said current sensing means is resistor having an electrical resistance of less than one ohm.
Claim 5
Dependent Claim
287 words
A lighting control apparatus to provide variable intensity light from a high-pressure discharge lamp load utilizing a photocoupler actuated by a variable duty-cycle circuit which varies the ON time of an LED in response to an externally generated electrical demand signal, said apparatus comprising: a. power control means having a signal input, a power input, and a power output, said power input being adapted to be connected to a source of AC power; b. ballasting means having an input and an output, said ballasting means input being connected to said power control means output; c. a discharge lamp load, said discharge lamp load being connected to the output of said ballasting means; d. variable duty-cycle circuit means having an input and an output, said demand signal adapted to be applied to the input of said variable duty-cycle circuit means; e. LED-photoresistor means for providing electrical isolation between said applied demand signal and said power control means, said LED-photoresistor means having an input and an output, and the output of said variable duty-cycle circuit means connected to the input of said LED-photoresistor means to cause said LED to be ON a percentage of the time which is proportional to the value of said demand signal; f. current sensing means connected with said power control means for developing a feedback signal; and g. an error-detecting circuit having an input connected to the output of said current sensing means and the output of said LED-photoresistor means for receiving the signals therefrom and generating an error output signal which corresponds to the difference between the received signals; and the output of said error-detecting circuit connected to the input of said power control means to control the current through said ballasting means.
Claim 6
Dependent Claim
287 words
A lighting control apparatus to provide variable intensity light from a high-pressure discharge lamp load utilizing a photocoupler actuated by a variable duty-cycle circuit which varies the ON time of an LED in response to an externally generated electrical demand signal, said apparatus comprising: a. power control means having a signal input, a power input, and a power output, said power input being adapted to be connected to a source of AC power; b. ballasting means having an input and an output, said ballasting means input being connected to said power control means output; c. a discharge lamp load, said discharge lamp load being connected to the output of said ballasting means; d. variable duty-cycle circuit means having an input and an output, said demand signal adapted to be applied to the input of said variable duty-cycle circuit means; e. LED-photoresistor means for providing electrical isolation between said applied demand signal and said power control means, said LED-photoresistor means having an input and an output, and the output of said variable duty-cycle circuit means connected to the input of said LED-photoresistor means to cause said LED to be ON a percentage of the time which is proportional to the value of said demand signal; f. current sensing means connected with said power control means for developing a feedback signal; and g. an error-detecting circuit having an input connected to the output of said current sensing means and the output of said LED-photoresistor means for receiving the signals therefrom and generating an error output signal which corresponds to the difference between the received signals; and the output of said error-detecting circuit connected to the input of said power control means to control the current through said ballasting means.
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) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |