Understanding flicker in a lighting system: as groups within the electrical industry wrestle with its definition, lamp flicker continues to be a problem

摘要

The visible brightening and dimming of lamps is known as flicker, and its severity in a lighting system usually depends on the frequency of the alternating current, the persistence (or retention) of light generated by the light source, and the actual viewing conditions. Typically, the eye cannot detect flicker at 60 Hz or 120 Hz, but it can in the 0 Hz to 30 Hz range. At first glance, an incandescent lamp appears to emit a constant light output. However, the value of the current-and therefore power-changes 120 times/sec. So why doesn't the lamp flash on and off 120 times a second, too? An incandescent source provides a constant lumen output because the filament doesn't have time to cool off during each power cycle.