quick question about bulbs.

for incandescents a higher voltage means the bulb will be brigther then a lower voltage one and even better if overdriven. But then there's mah rating or usually around 500-800 i know this is the battery consumption usually but what would be the difference in light characteristics in a 4.8v 500mah bulb and a 4.8v 800mah bulb? ahhhhhhhhhhh! it seems to get much hotter too which risks melting my plastic reflector.

The light output of a incandesent bulb is affected by a many things. Power is number one. (P=EI) The 4.8v 0.5A bulb is burning 2.4 watts. The 4.8v 0.8A bulb is burning 3.84 watts. This is 1.44 watts more than the first,more than a 50% increase. A higher voltage bulb can have a longer filament having more area to radiate photons from for the same current as a lower voltage bulb. The design of the filament and bulb envelope can make one better than the next. The more heat on the filament the brighter it glows and the whiter it will be, the design of the filament and glass envelope has an effect on how hot the filiment will operate for a given amount of power consumption.

wow thanks cool! that explained alot. but just not sure how you calculated the wattage.

Simple, multiply the volts by the amps to get the watts.
P=VI or V*I.

Pee on the ivy

wow, i never thought about a higher voltage bulb having a longer filiment, and as such a higher resistance and needing more voltage to overpower that resistance. thanks for expanding the way i think about bulbs :-D

- Pete

Originally posted by carbonsparky:
The light output of a incandesent bulb is affected by a many things. Power is number one. (P=EI) A higher voltage bulb can have a longer filament having more area to radiate photons from for the same current as a lower voltage bulb.

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