View Single Post
  #29   Report Post  
Posted to alt.home.repair
Bob F Bob F is offline
external usenet poster
 
Posts: 8,803
Default Basic DC electricity question


"Doug Miller" wrote in message
...
In article W6HAh.3741$Aa5.925@trnddc01, "Pop`"

wrote:
w_tom wrote:
Light bulbs work at may voltages. For example, a 120 volt
incandescant bulb will work at 60 volts AND last for maybe 100 years
continuous. As voltage drops, bulb life expectancy increases
exponentially (about a factor of 12). As voltage drops, bulb
intensity also decreases exponentially. Sure, the 12 volt bulb will
work at 6 volts. But its light output will be massively diminished
and its efficiency is decreases (less light per amp of electricity).

So yes, a 12 volt lamp will work on 6 volts (if power supply can
provide sufficient current). Just not work very well.


NO, it will not. There will be insufficient heat in the element to

provide
any light or even a glow with a 12V bulb at 6V DC. A 12VDC bulb will

begin
to dim substantially at 9 VDC and may not even be visible in the light of

a
room.


I guess you didn't understand the part where he said "if power supply can
provide sufficient current."


If the voltage is insufficient, no power supply, no matter what current it
can deliver, will light the bulb.


Do not profess knowledge you do not have.


That's good advice, Poop. Maybe you should take it, too.


You say?

Bob