Quote Originally Posted by logroller View Post
A light bulb is a resistor, just not an ohmic one. As the current increases through the filament it heats up, as well as emitting light, and as the heat increases the resistance increases and more energy is expelled as light and heat. Since a light bulb is not an ohmic resistor, meaning it does not have constant resistance across a range of current (its resistance increases), to mitigate the potential for oxidation the current is decreased by way of reduced voltage. If a lightbulb is operated with alternating current, the standard device used to reduce the current/voltage, effectively dimming the bulb, is a triode-- not a resistor. A triode clips the sine wave of alternating current effectively reducing the voltage supply. It actually turns on and off 240 times per second. (In the us since we have 60Hz)
as for the bulb in question, it likely has a transforming power supply that provides a lesser voltage rather than toggling the current on and off as this has detrimental effect on filament life as well-- as demonstrated by bulbs typically burning out when current is first introduced after you flick the switch.
Yes and I also mentioned a power supply to that particular bulb. As dim as it is, the power to the bulb is low.