Patent US3893002A successfully refreshed from Google Patents.
US3893002A
Expired / Lapsed
US
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Switch-controlled continuously progressive dimmer circuit
Assignee: Individual
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Filing: 1974-02-19
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Granted: 1975-07-01
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Expires: 1994-02-19
Abstract
Abstract A dimmer circuit for lighting in which the brightness of a lamp or lamps is controlled by the potential across a storage capacitor. The potential may be varied by operating a switch and the rate of charge/discharge is such as to enable a user to adjust the brightness of a lamp progressively to a required level. A number of dimmer circuits may be combined to form a lighting control system in which some switches control only one or two lamps while others are master switches for controlling several lamps. For example in a hotel suite master switches by the door and the bed may control all the lamps while a separate switch controls one reading lamp only.
Inventors
- 👤 John Peter Woodnutt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:45
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/257; H02M5/2573
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
158 words
A dimmer circuit comprising: output power control means adapted for connection in a power supply circuit of a lamp; a storage capacitor; conversion means connected to said storage capacitor and to said output power control means to cause said output power control means to set the power available to a lamp in whose power supply circuit the output power control means is connected, to a level dependent on te potential across said storage capacitor; and manually-operable switch controlled charge-varying means connected to said storage capacitor and operable in a first mode to allow the charge on said storage capacitor to remain unaltered and in a second mode to cause progressive and continuous alteration of said charge at such a rate as to enable a user to progressively and continuously vary the brightness of said lamp to a required level by employing said second mode of operation and then to retain said level by switching to said first mode.
Claim 2
Dependent Claim
158 words
A dimmer circuit comprising: output power control means adapted for connection in a power supply circuit of a lamp; a storage capacitor; conversion means connected to said storage capacitor and to said output power control means to cause said output power control means to set the power available to a lamp in whose power supply circuit the output power control means is connected, to a level dependent on te potential across said storage capacitor; and manually-operable switch controlled charge-varying means connected to said storage capacitor and operable in a first mode to allow the charge on said storage capacitor to remain unaltered and in a second mode to cause progressive and continuous alteration of said charge at such a rate as to enable a user to progressively and continuously vary the brightness of said lamp to a required level by employing said second mode of operation and then to retain said level by switching to said first mode.
Claim 3
Dependent Claim
23 words
A dimmer circuit according to claim 1, wherein said storage capacitor has a time constant for charge leakage of at least 10 hours.
Claim 4
Dependent Claim
33 words
A dimmer circuit according to claim 1, wherein said conversion means comprises an amplifier having and input of very high impedance connected across said storage capacitor and an output of relatively low impedance.
Claim 5
Dependent Claim
77 words
A lighting control system comprising first and second dimmer circuits according to claim 1 with associated lamps, the switch-controlled charge-varying means of said first and second dimmer circuits being connected to their respective storage capacitors to provide independent dimmer control of their respective lamps, and an additional switch-controlled charge-varying means connected to both said storage capacitors to provide simultaneous dimmer control of both lamps independently of said switch-controlled charge-varying means of said first and second dimmer circuits.
Claim 6
Dependent Claim
43 words
A dimmer circuit according to claim 1 wherein said switch controlled charge-varying means can be selectively actuated in said second mode of operation to either charge said storage capacitor to said required level or to discharge said storage capacitor to said required level.
Claim 7
Dependent Claim
31 words
A dimmer circuit according to claim 1, wherein said output power control means comprises a triggerable control element having a trigger electrode, said trigger electrode being connected to the conversion means.
Claim 8
Dependent Claim
15 words
A dimmer circuit according to claim 6, wherein said triggerable control element is a triac.
Claim 9
Dependent Claim
39 words
A dimmer circuit according to claim 6, wherein said conversion means includes a variable phase delay network adapted to provide a trigger signal to said trigger electrode at a phase position determined by said potential across said storage capacitor.
Claim 10
Dependent Claim
132 words
A dimmer circuit according to claim 1, wherein said switch-controlled charge-varying means comprises a source of alternating current, a first unidirectional element, a second unidirectional element, and a switch having a first terminal connected to said storage capacitor via said first unidirectional element, a second terminal connected to said storage capacitor via said second unidirectional element and a common terminal switchable to either said first or said second terminals to effect said second mode of operation, said common terminal being connected to said source of alternating current and said unidirectional elements being so biased that connection of said alternating current source, in operation, to said storage capacitor via one of said unidirectional elements causes said storage capacitor to charge and connection via said other unidirectional element causes said storage capacitor to discharge.
Claim 11
Dependent Claim
31 words
A dimmer circuit according to claim 9, having a resistor connected in series with each of said unidirectional elements to determinine the rate of charge and discharge of said storage capacitor.
Claim 12
Dependent Claim
45 words
A dimmer circuit according to claim 9 including a plurality of switches each having a common terminal adapted for connection to said source of alternating current and each having first and second terminals connected to said storage capacitor via unidirectional elements individual to each terminal.
Claim 13
Dependent Claim
34 words
A dimmer circuit according to claim 11, wherein resistors of different values are connected in series with said unidirectional elements so that said switches vary the charge of said storage capacitor at different rates.
Claim 14
Dependent Claim
36 words
A dimmer circuit according to claim 9, wherein said storage capacitor has one of its terminals connected to a reference potential and the other one of its terminal connected via said unidirectional elements to said switch.
Claim 15
Dependent Claim
41 words
A dimmer circuit according to claim 13, wherein said source of alternating current is adapted to produce a current having a potential which alternates between said reference potential and a maximum potential to which said storage capacitor is to be charged.
Claim 16
Dependent Claim
67 words
A dimmer circuit according to claim 13, including a unidirectional clamping element wherein said source of alternating current is adapted to produce a current having a potential which alternates about said reference potential while said storage capacitor has its said other terminal clamped to said reference potential by said unidirectional clamping element to protect said storage capacItor from being charged to a potential of the wrong polarity.
References Cited (Backward Citations)
US3706913A
Cited
US3715623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |