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In visual perception, flicker is a human-visible change in luminance of an illuminated surface or light source which can be due to fluctuations of the light source itself, or due to external causes such as due to rapid fluctuations in the voltage of the power supply (power-line flicker) or incompatibility with an external dimmer.
Dimming fluorescent ballasts and dimming LED drivers often use 0–10 V control signals to control dimming functions. In many cases, the dimming range of the power supply or ballast is limited. If the light output can only be dimmed from 100% down to 10%, there must be a switch or relay available to kill power to the system and turn the light ...
Fluorescent light fixtures cannot be connected to dimmer switches intended for incandescent lamps. Two effects are responsible for this: the waveform of the voltage emitted by a standard phase-control dimmer interacts badly with many ballasts, and it becomes difficult to sustain an arc in the fluorescent tube at low power levels.
Fluorescent bulbs contain mercury, a toxic substance. The United States Environmental Protection Agency (EPA) provides safety guidelines for how to clean up a broken fluorescent bulb. [17] Mercury can be harmful to children and developing fetuses, so children and pregnant women should avoid being in the area whilst a broken bulb is cleaned up. [18]
To house this device, he decided on a 2-inch round device with one end capable of being screwed into a light bulb socket and the other end able to receive a light bulb. [4] When solid-state dimmers came into use, analogue remote control systems (such as 0-10 V lighting control systems) became feasible. The wire for the control systems was much ...
Burst dimming is a method to control dimming of cold cathode fluorescent lamps (CCFLs) and LEDs by using pulse width modulation (PWM) at approximately 100-300 Hz which is supposed to be above the noticeable flicker limit for the human eye. [1] This technique is sometimes used with TFT displays to control backlighting. An alternative dimming ...
A lighting control console (also called a lightboard, lighting board, or lighting desk) is an electronic device used in theatrical lighting design to control multiple stage lights at once. They are used throughout the entertainment industry and are normally placed at the front of house (FOH) position or in a control booth .
The requirements of a flicker measurement equipment are defined in the international electro-technical standard IEC 61000-4-15. [2]A flickermeter is composed of several function blocks which simulate a 230 V/60 W or a 120 V/60 W incandescent lamp (reference lamp) and the human perception system (eye-brain model).