RE: Why do bulbs explode?

["Ian Lowe" <ian@xxxxxxx>]

Hmm, I know this:

Most household bulbs are "semi" airtight, and have a reduced
oxygen
atmosphere in them, in an attempt to reduce oxidation of the filament.

Two things cause bulbs to explode:

Either a very large surge that causes a large chunk of the filament to
vaporise, rather than a small bit of it to melt.. just like any
explosion, rapid increase of gas volume from the vaped metal, confined
space, the glass envelope can't take the sudden increase in pressure -
"pop"

Or, secondly, the thing is made bad.. weak glass, pressure of the
artificial atmosphere a little high inside, filament too thick those
sorts of things..

I *believe* the ceramic base of some bulbs is intended as a
pressure-safe element, so that it breaks when the filament blows, this
failing to work is also a "bad manufacture" thing.

Personally, I'd try another make of bulb in the same socket.. if it
blows too, you got some dodgy wiring that's delivering *nasty* spikes to
that socket!!

I.

-----Original Message-----
From: Quinten Uijldert [mailto:yahoogroups@xxxxxxx]
Sent: 03 February 2004 15:01
To: ukha_d@xxxxxxx
Subject: [ukha_d] Why do bulbs explode?

SWMBO just phoned me as one of the light bulbs in my kitchen has
exploded
whilst she was there.  This has happened now twice and both with the
same
socket.  Does anyone have any suggestions as to what is the most likely
reason
that might have caused this?  A power spike?  Bad manufacturing of the
bulb?

Q.

PS: No, I'm not living on a ancient burial ground, at least, not as far
as I'm
aware ;)

--
Very funny Scotty. Now beam down my clothes!

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