# which is brighter? 12V or 6V



## hairydogs (May 2, 2002)

As captioned.


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## Jonathan (May 2, 2002)

Neither.

Voltage does not produce light. Just try staring at a 1.5V battery and than a 9V battery for a while.







I presume that you are asking about lights which run on 12V or 6V. The reality is that it strongly depends upon the design of the light, so strongly that I would not care to lay odds on the brightness of any random 12V versus 6V light.

The total flux of light produced will depend upon the wattage of the lamp and the efficiency of the lamp. A 30W 6V lamp will almost certainly produce more light than a 10W 12V lamp.

Additionally, brightness (as in candlepower) depends both upon the total flux of light, and how well it is concentrated by any optics. So two lamps with exactly the same light output can have vastly different candlepower ratings.

For the same lamp wattage, a higher voltage lamp will require lower current. Since current causes heating in wires and switches and the like, one generally finds that higher wattage lamps are designed to run at higher voltages.

12V is also a very common voltage available for portable applications, since it is used in cars. Thus you will see a greater selection of lamps available which will run at 12V. 12V is very commonly used in low voltage halogen lighting systems, and some of these same lamps are used in portable lighting systems, since they are cheap and pretty good.

So if I were designing a lamp up from scratch, and I wanted a bright, inexpensive lamp, I would probably go with a 12V system...but this is not set in stone or an absolute fact.

-Jon


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