Patent
Low distortion line dimmer and dimming ballast
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TLDR
In this paper, a line dimmer has a limited maximum firing angle to limit a total harmonic distortion within a powering signal, and a dimming ballast generates a pulse width modulated signal based on a firing angle of the powering signal.Abstract:
A line dimmer has a limited maximum firing angle to limit a total harmonic distortion within a powering signal. A dimming ballast generates a pulse width modulated signal based on a firing angle of the powering signal, generates a dimming command signal based on the pulse width modulated signal, and dims a lamp based on the dimming command signal. The maximum firing angle may be limited to 30 degrees, 25 degrees, or 20 degrees, for example, to limit a resulting total harmonic distortion.read more
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References
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Patent
Remote control of fluorescent lamp ballast using power flow interruption coding with means to maintain filament voltage substantially constant as the lamp voltage decreases
TL;DR: In this article, the light output of a fluorescent lamp is controlled by a remote source via a voltage control feedback loop, the dimming function being achieved by varying the set point of the control loop.
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Coded communication system and method for controlling an electric lamp
TL;DR: In this paper, a two-wire dimming method for gas discharge lamps is proposed, in which the voltage signal carrying the encoded commands is the sinusoidal mains voltage powering the ballast, since the encoded perturbations may be small enough to avoid lamp flicker even with encoded signals on the line voltage.
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Electronic ballast with interface circuitry for multiple dimming inputs
TL;DR: In this article, a gas discharge lamp dimming ballast has been used to communicate with a power line wall controller, such as phase angle control, step control, and coded control.
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TL;DR: In this article, a photocell is used to obtain information on ambient light levels through an ambient light gathering prism mounted through a ceiling tile near the fixture, and connected to the circuit housing by a flexible fiber optic cable.
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Power line communication system.
TL;DR: In this paper, the transmitter combines the 60 Hz clock signal and 120 Hz with data from a shift register for interrupting current in a predetermined pattern wherein an interruption of the positive zero crossings and negative zero crossings defined a logic "1" and no interruption defined a "0" logique.