US3868544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lamp flasher
Assignee: Individual
•
Filing: 1973-08-02
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Granted: 1975-02-25
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Expires: 1993-08-02
Abstract
Abstract A plurality of incandescent lamps, such as those used in an illuminated display sign, are energized from an A.C. power source via a triac connected in series with each lamp. The firing angle of each triac is controlled by a free-running multivibrator having a frequency very close to, but different from, the frequency or a harmonic of the A.C. power frequency. Therefore, the power applied to the lamps is gradually increased or decreased in a repetitious and periodic manner to create an eyecatching effect and also to increase the lifetime of the filaments of incandescent lamps.
Inventors
- 👤 Donald S Banks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:59
CPC Classifications
H; H05; H05B; H05B39/00; H05B39/04; H05B39/08; H05B39/083
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
A power modulator for periodically modulating the power applied to a load from an A.C. power source comprising: a. controllable A.C. switch means adapted to be coupled between the source and the load, and b. control signal generator means coupled to said A.C. swItch means for continuously generating control signals for controlling the time in each half-cycle of A.C. power at which the switch means is rendered conductive; c. the frequency at which the control signals are generated being very close to, but different from, the frequency of the A.C. power source or a harmonic thereof, so that the phase difference between successive control signals and corresponding A.C. power cycles continuously and cyclically varies, whereby the A.C. power applied to the load also continuously and cyclically varies.
Claim 2
Dependent Claim
127 words
A power modulator for periodically modulating the power applied to a load from an A.C. power source comprising: a. controllable A.C. switch means adapted to be coupled between the source and the load, and b. control signal generator means coupled to said A.C. swItch means for continuously generating control signals for controlling the time in each half-cycle of A.C. power at which the switch means is rendered conductive; c. the frequency at which the control signals are generated being very close to, but different from, the frequency of the A.C. power source or a harmonic thereof, so that the phase difference between successive control signals and corresponding A.C. power cycles continuously and cyclically varies, whereby the A.C. power applied to the load also continuously and cyclically varies.
Claim 3
Dependent Claim
118 words
A repetitive power modulator for repetitively and periodically modulating the power of a signal applied from an A.C. source to a load comprising: a. A.C. phase control means adapted to be coupled between the A.C. source and the load and having a control element responsive to a control signal for becoming conductive at a point in each A.C. cycle, and b. control signal generating means coupled to said control element and continuously producing a control signal having a frequency different from, but quite close to, the A.C. signal frequency, so that the A.C. power applied to the load is continuously and periodically modulated in accordance with the difference in frequency of said control signals and said A.C. signals.
Claim 4
Dependent Claim
118 words
A repetitive power modulator for repetitively and periodically modulating the power of a signal applied from an A.C. source to a load comprising: a. A.C. phase control means adapted to be coupled between the A.C. source and the load and having a control element responsive to a control signal for becoming conductive at a point in each A.C. cycle, and b. control signal generating means coupled to said control element and continuously producing a control signal having a frequency different from, but quite close to, the A.C. signal frequency, so that the A.C. power applied to the load is continuously and periodically modulated in accordance with the difference in frequency of said control signals and said A.C. signals.
Claim 5
Dependent Claim
128 words
A lamp flasher circuit for continuously and periodically varying both the flashing frequency and illumination intensity of a plurality of lamps wherein the circuit is adapted to be connected between a source of A.C. voltage and the lamps, the circuit comprising: a. controllable A.C. switch means adapted to be connected between the source and each lamp, and b. signal generating means for continuously generating control signals for opening and closing of said switch means, the frequency of said control signals being fixed and different from the A.C. voltage frequency or a harmonic thereof, whereby the illumination of said lamps is cyclically and continuously varied from a full intensity condition to an off condition at a frequency equal to the difference between the control signal and A.C. voltage frequencies.
Claim 6
Dependent Claim
128 words
A lamp flasher circuit for continuously and periodically varying both the flashing frequency and illumination intensity of a plurality of lamps wherein the circuit is adapted to be connected between a source of A.C. voltage and the lamps, the circuit comprising: a. controllable A.C. switch means adapted to be connected between the source and each lamp, and b. signal generating means for continuously generating control signals for opening and closing of said switch means, the frequency of said control signals being fixed and different from the A.C. voltage frequency or a harmonic thereof, whereby the illumination of said lamps is cyclically and continuously varied from a full intensity condition to an off condition at a frequency equal to the difference between the control signal and A.C. voltage frequencies.
Claim 7
Dependent Claim
17 words
A lamp flasher circuit as defined in claim 3 wherein said A.C. switch means comprises a triac.
Claim 8
Dependent Claim
23 words
A lamp flasher circuit as defined in claim 1 wherein the difference in said frequency is between zero and three cycles per second.
References Cited (Backward Citations)
US3299319A
Cited
US3745382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |