Patent US3821601A successfully refreshed from Google Patents.
US3821601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regulated dimmer for incandescent lamps
Assignee: HARRINGTON RONALD G
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Filing: 1973-06-13
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Granted: 1974-06-28
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Expires: 1993-06-13
Abstract
Abstract A regulated lighting control apparatus to control RMS voltage supplied to an incandescent lamp load from an A.C. power source in response to an electrical demand signal. This apparatus utilizes a comparison between a signal which is a function of the demand signal and a signal proportional to the RMS value of the voltage across the load to control the amount of power supplied to the load. The apparatus also contains a voltage reset means to periodically restore the firing initiating capacitor to a predetermined voltage. Preferably the apparatus also senses the load current, and if the current tends to rise above the rated current of the apparatus, the comparison of the signals is modified so as to prevent the drawing of excess current.
Inventors
- 👤 G Kappenhagen
- 👤 J Tabor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:13
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/12; G05F1/40; G05F1/44; G05F1/445; G05F1/66
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
310 words
A regulated lighting control apparatus responsive to an electrical demand signal to control the RMS voltage supplied to an incandescent lamp load from an A.C. power source said apparatus comprising: a. solid-state switching means adapted to be connected in series with said load across said A.C. power source; b. a firing means having an output connected to said solid-state switching means which firing means renders said solid-state switching means conductive when said firing means is initiated; c. a firing initiating capacitor connected to said firing means for initiating said firing means when a predetermined voltage is across said firing initiating capacitor; d. a voltage reset means connected to said firing initiating capacitor for adjusting the voltage across said firinginitiating capacitor to a predetermined voltage; e. a charging rate control circuit connected to said firing initiating capacitor for controlling the rate at which said firing initiating capacitor is charged; f. a comparator circuit having first and second inputs and having an output connected to said charging circuit, the signal at said comparator output being effective to adjust said charging rate control circuit in response to the difference between the signals on said inputs of said comparator circuit whereby an error signal to correct the firing initiating capacitor charging rate is developed; g. a shaping circuit having an output connected to said first input of said comparator circuit, said shaping circuit being adapted to receiving said demand signal and to generating an output signal which is a function of said demand signal; h. an RMS computing means having an output connected to said second input of said comparator circuit; and i. a load voltage sensing means having an output connected to said RMS computing means, whereby the proportion of time during which said solid-state switching means conduct is controlled to provide RMS voltage across said load to produce the desired luminous intensity.
Claim 2
Dependent Claim
310 words
A regulated lighting control apparatus responsive to an electrical demand signal to control the RMS voltage supplied to an incandescent lamp load from an A.C. power source said apparatus comprising: a. solid-state switching means adapted to be connected in series with said load across said A.C. power source; b. a firing means having an output connected to said solid-state switching means which firing means renders said solid-state switching means conductive when said firing means is initiated; c. a firing initiating capacitor connected to said firing means for initiating said firing means when a predetermined voltage is across said firing initiating capacitor; d. a voltage reset means connected to said firing initiating capacitor for adjusting the voltage across said firinginitiating capacitor to a predetermined voltage; e. a charging rate control circuit connected to said firing initiating capacitor for controlling the rate at which said firing initiating capacitor is charged; f. a comparator circuit having first and second inputs and having an output connected to said charging circuit, the signal at said comparator output being effective to adjust said charging rate control circuit in response to the difference between the signals on said inputs of said comparator circuit whereby an error signal to correct the firing initiating capacitor charging rate is developed; g. a shaping circuit having an output connected to said first input of said comparator circuit, said shaping circuit being adapted to receiving said demand signal and to generating an output signal which is a function of said demand signal; h. an RMS computing means having an output connected to said second input of said comparator circuit; and i. a load voltage sensing means having an output connected to said RMS computing means, whereby the proportion of time during which said solid-state switching means conduct is controlled to provide RMS voltage across said load to produce the desired luminous intensity.
Claim 3
Dependent Claim
67 words
The apparatus of claim 1, wherein a current limiting means is included, said current limiting means being responsive to the current flowing through said load and being effective to detect when said current exceeds a predetermined value, and to modify the relative magnitude of said shaping circuit output signal and said RMS computing means output signal, whereby said current is prevented from significantly exceeding said predetermined value.
Claim 4
Dependent Claim
57 words
The apparatus of claim 1, wherein said function is such that said output signal is essentially proportional to the 0.5 to 0.7 power of said demand signal whereby a demand signal directly proportional to a desired apparent luminous intensity is converted into a shaped-demand signal proportional to the RMS voltage necessary to produce that apparent luminous intensity.
Claim 5
Dependent Claim
34 words
The apparatus of claim 3, wherein said shaping circuit has two Darlington circuits connected generally in parallel to generate a shaped-demand signal which is essentially proportional to the 0.59 Power of said demand signal.
Claim 6
Dependent Claim
34 words
The apparatus of claim 3, wherein said voltage reset means adjusts said voltage across said firing initiating capacitor to a predetermined voltage each time the voltage of said A.C. power source passes through zero.
Claim 7
Dependent Claim
61 words
The apparatus of claim 5, wherein said predetermined voltages to which said firing initiating capacitor is adjusted is about zero and said voltage reset means has a shorting transistor and a Zener diode, which Zener diode, when the voltage of the A.C. power source falls below a predetermined level, causes said shorting transistor to conduct and discharge said firing initiating capacitor.
Claim 8
Dependent Claim
14 words
The apparatus of claim 6, wherein said firing means comprises a two-transistor trigger circuit.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |