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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]
A stroboscopic effect can be noticed, where something spinning at just the right speed may appear stationary if illuminated solely by a single fluorescent lamp. This effect is eliminated by paired lamps operating on a lead-lag ballast. Unlike a true strobe lamp, the light level drops in appreciable time and so substantial "blurring" of the ...
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.
These phenomena can potentially generate vibrations of the ferromagnetic, conductive parts, coils and permanent magnets of electrical, magnetic and electromechanical device, resulting in an audible sound if the frequency of vibrations lies between 20 Hz and 20 kHz, and if the sound level is high enough to be heard (e.g. large surface of ...
Temporal light artefacts (TLAs) are undesired effects in the visual perception of a human observer induced by temporal light modulations. Two well-known examples of such unwanted effects are flicker and stroboscopic effect. Flicker is a directly visible light modulation at relatively low frequencies (< 80 Hz) and small intensity modulation levels.
The main cause of ringing artifacts is overshoot and oscillations in the step response of a filter.. The main cause of ringing artifacts is due to a signal being bandlimited (specifically, not having high frequencies) or passed through a low-pass filter; this is the frequency domain description.
Fluorescent_beat_effect.ogv (Ogg Theora video file, length 15 s, 640 × 480 pixels, 3.35 Mbps, file size: 6.05 MB) This is a file from the Wikimedia Commons . Information from its description page there is shown below.
However, a faulty fluorescent lamp can flicker at a much lower rate and trigger seizures. [medical citation needed] Newer high-efficiency compact fluorescent lamps (CFL) with electronic ballast circuits operate at much higher frequencies (10–20 kHz) not normally perceivable by the human eye, though defective lights can still cause problems.