<VV> Bulbs burn out quickly?

[Frank DuVal]

No, the feed is still just a nominal 12 volts (nominal because it 
actually varies between 12 and 14 volts as battery condition/charging 
system). You can put any 12 volt bulb directly across the battery and it 
will burn just fine, not burn out. The current is determined by the 
resistance of the bulb, not resistance of the wiring. The resistance of 
the wiring should be close to zero.

Now if you get the 1157 bulb in 180° wrong, the dim filament will be 
tied into the turn signal flasher, and this lower operating current will 
cause the flasher to not act correctly. But the bulb will be fine even 
if the flashing spped is wrong. The bright filament will be on with the 
taillamps, and it will also be happy. Those following you will not, as 
it will seem your have your foot on the brake all the time.

Frank

ScottyGrover at aol.com wrote:

> In a message dated 5/11/2008 11:44:51 A.M. Pacific Daylight Time, 
> corvairduval at cox.net writes:
>
>     No,  Ron is right. The current through a bulb is determined by the
>     available volatge and the resistance of the bulb. E=IR, I=E/R
>     ohm's law.
>     The only way to get more current through the bulb is to apply more
>     voltage. Even if you put the bulb in series with the starter
>     motor, the
>     current through the bulb would not exceed its normal current. Of
>     course
>     the starter motor would not run, since now its current is limited.
>
>     Frank DuVal
>
> True, but the original question involved putting the bulb into the 
> socket wrongly, so that high current was being supplied to a bulb that 
> wasn't supposed to get that much.  Wouldn't that cause early burnout?
>  
> Scotty from Hollyweird
>
>
>