"JoRob64"
"Phil Allison"
"Graham."


An incandescent light bulb is a good example, If it lasts 1000 hours
when run continuously, its life will be considerably shorter if run
(say) 4 hours a day and the time it is on added up.


** Where ever did you get that nonsense from ??

Some web forum ?

I believe turning the bulbs on and off can induce thermal shock which
causes premature failure.


** ******** it does.

There are many applications where incandescent lamps are turned on and off
constantly and their life span is the same.

The OP's hypothetical example ( don't ya just LOVE them) is typical of
domestic lamp use.

****wit.


..... Phil

Phil Allison wrote:
"JoRob64"
"Phil Allison"
"Graham."


An incandescent light bulb is a good example, If it lasts 1000
hours when run continuously, its life will be considerably shorter
if run (say) 4 hours a day and the time it is on added up.


** Where ever did you get that nonsense from ??

Some web forum ?

I believe turning the bulbs on and off can induce thermal shock which
causes premature failure.


** ******** it does.

There are many applications where incandescent lamps are turned on
and off constantly and their life span is the same.

The OP's hypothetical example ( don't ya just LOVE them) is typical of
domestic lamp use.

****wit.


.... Phil

No Phil, that is not correct. If he only listens to Rap , its lifespan will
be shortend greatly.
Buffalo

On 03/10/2012 01:25, Phil Allison wrote:
There are many applications where incandescent lamps are turned on and off
constantly and their life span is the same.


There were many installations using thermionic valves where very long
life was achieved by leaving them running continuously. The GPO had
discovered this and it influenced Bletchley Park with their early
computers, some did not believe they would get a reliable system but the
GPO engineers working there convinced them that it was possible.

There are frequent stories in the press of incandescent light bulbs that
have been running continuously for very long periods - tens of years.

On Wed, 03 Oct 2012 09:12:34 +0100, MB wrote:
There are frequent stories in the press of incandescent light bulbs that
have been running continuously for very long periods - tens of years.

110 years:
http://www.centennialbulb.org

Of course, the lifetime of light bulbs is part of an international
conspiracy to promote planned obsolescence:
http://topdocumentaryfilms.com/light-bulb-conspiracy/

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558