charles expressed precisely :
In article ,
Dave Plowman (News) wrote:
In article ,
Harry Bloomfield wrote:
David pretended :
Thanks. The dimmer switch was mentioned and is a good idea. The only
reservation was that I remember them as a knob with push for on and
off and turn for brightness. Is there such a thing as a "normal"
switch with a variable setting for brightness??

Dimmers are not a very efficient way to run ordinary lamps and
especially halogen lamps. Light output drops markedly as a larger
proportion of the power goes to producing heat.

True. However, if a light is too bright it reduces that output. It may
reduce the paper efficiency - but it doesn't cost you more in electricity.
If you are concerned about the very best working light for your penny,
change to a more efficient method of providing that light. But the problem
is (as in the OP's case) some want the device producing the light to be
attractive too.


Halogen lamps can be
blackened by the use of a dimmer.

I've read this many times and it simply doesn't happen here - with lots of
assorted halogen on dimmers. Only time I've seen blackened halogen bulbs
is in a car headlight. And I've no explanation as to why. Car headlights
are near always run with the voltage at near the 'correct' value. Very few
would run them for long with the engine stopped, so voltage below about
13.5v.

There used to a function called "DimDip" which seriously reduced the
voltage to headlights so that they could be used as running lights. As
halogen lamps came in DimDip was dropped because of the blackening problem.
In the theatre, lamps tended to die becasue, in general, from handling
problems rather tha partial blackening due to lower voltage.

That is not what I read - I read that it was dropped because the EU
would not accept it. One of my cars had it and it was perfect for use
in built up areas, where dipped tended to blind both pedestrians and
other drivers, to what was behind you/me.