"N_Cook" <diverse@[EMAIL PROTECTED]
> wrote in message
news:g4kifj$17b$1@[EMAIL PROTECTED]
> Arfa Daily <arfa.daily@[EMAIL PROTECTED]
> wrote in message
> news:y4ebk.387$jB5.114@[EMAIL PROTECTED]
>> For twenty odd years, I have had the same Terry's Anglepoise bench lamp
>> in
>> service. I have always used perfectly normal 60 watt incandescent lamps
>> in
>> it, without any problem at all. Although the metal shade used to get
>> quite
>> warm, it was never enough to actually burn you when your forehead
>> accidentally connected with it.
>>
>> Recently, the light bulbs I've been seeing and buying, seem to have
> reduced
>> in size from the old 'tennis ball' size, to something closer to a
snooker
> or
>> pool ball (but not as small as the established 'golf ball' types often
> used
>> in multibranch ceiling lights and light / fan fittings.)
>>
>> I have noticed that these new smaller bulbs run a whole quantum leap
> hotter
>> than the older larger size, and they hot up the shade on the bench
light
>> until it is unbearably hot to touch. Today, I left the workshop for a
> while,
>> and when I came back, the air was full of that 'fishy' sort of smell
you
> get
>> when something like a wall socket or the plug that's in it, is burning.
A
>> hunt around for the source, brought me to the bench lamp, which was
still
>> alight. When I moved it, it went off. When it had cooled down a bit, I
> took
>> the bulb out (a UK bi-pad bayonet cap rather than a U.S. edison screw
> type)
>> and I was horrified to see that one of the solder pads had just about
> burnt
>> away completely, and the black insulation material in the base had
>> started
>> to burn as well. Fortunately, the brass lampholder was undamaged.
>>
>> So, has anyone else noticed how hot these smaller bulbs run ? Are we
> talking
>> dangerous here if they are used in any fitting where they hang
downwards
>> ?
>> Any suggestions as to why there is such a large increase in temperature
?
>> Yes, I can see that the glass envelope is closer to the filament, and
>> that
>> it has somewhat less surface area to radiate the heat away from, but
I'm
> not
>> sure that either of those are enough to account for just how much
hotter
>> they seem to run. And why had one pad burnt away?Anything to do with
the
>> solder being lead-free and less malleable than before, reducing the
>> spring
>> loaded contact area maybe ?
>>
>> A bit worrying as I'm sure that there will be many situations where a
>> fitting that has previously been quite happy with a 60 watt bulb in it,
> will
>> now overheat, with possibly catastrophic consequences ...
>>
>> Arfa
>>
>>
>
> I usually use circular fluourescent lamp of an anglepoise inspection
lamp
> for bench illumination but sometimes use a traditional one (Luxo for
those
> over there). In that I have a 60Watt one that is conical in shape, like
> Apollo earth lander capsule, that has silvering on the cone so directs
> both
> heat and light forwards unlice dichroic which is designed to pass heat
> through to the rear and light forward. The cover gets about as hot as
> something less than a 40W standard bulb. They may be used for shop
display
> purposes these silvered bulbs. As most of the rearwar light is directed
> forwards more efficiently than a cluttered white cover then perhaps
> equivalent to standard 150W illumination in the direction where you want
> it
>
> The ones I have are coloured but I scrape the varnish off the front,
Endon
> Accessories Reflector R080 type
>
> --
> Diverse Devices, Southampton, England
> electronic hints and repair briefs , schematics/manuals list on
> http://home.graffiti.net/diverse:graffiti.net/
>
>
I'll have a look for some. Without any desire to re-open the CFL thing
again, I currently have one of those in it, as it was all I had to hand.
The
light from it is useless in this application ...
Arfa
|
