"David Eather" wrote in message
news
p.wrdk0ae1wei6gd@phenom-pc...
On Thu, 24 Jan 2013 03:04:10 +1000, Spehro Pefhany
wrote:
On Wed, 23 Jan 2013 16:41:16 -0000, "Ian Field"
wrote:
"Phil Allison" wrote in message
...
"Ian Field"
"Phil Allison"
FWIW, of the modest pile of CFLs I autopsied from my own house, 100%
of the failures were from failed heaters.
** Most CFLs have PTC thermistors that increase current flow to the
heater for the first few seconds - makes the lamp start quickly,
particularly in cool weather conditions.
It also burns out the heater in a few hundred or so cycles.
Claims for life spans of 6 or 8 thousand hours are based on
continuous
use in a cool environment - plus lotsa good luck.
This may be atypical. I get good service from CFLs running them
without enclosures; the enclosed, base-up fail modes may be
different.
** Recently, a neighbour had an 18W CFL explode and bits go all over
the
kitchen - it was base up in a non ventilated fitting.
Must've been a pretty big explosion for bits to go everywhere from a
non-ventilated fitting!
** See the second half of this page for pics of the actual CFL and
fitting.
http://sound.westhost.com/articles/il-cfl-6.htm
The are no ventilation a holes at the back of the fitting and all the
spiral CFLs were a neat fit.
Even stupid people should know better than put CFLs in a fitting like
that!
I must be stupid then. I've got a CFL in a totally sealed (shower)
fixture and it's been working fine for years. (I even conformally
coated the lamp before sealing it in the fixture).
I only buy name brand (eg. Philips) products though, and probably
they're made a bit better than the ones that come 8 to a card. Never
seen any perforation of the housings on failure.
Nope. I lost three Philips to one power surge and on pulling them apart I
can confirm they use the same caps or worse - mine were marked as 350V DC.
Considering the mains was 240v AC thats not a lot of a safety margin.
In a TV or monitor you'd find 385V minimum, more likely 400V. Although
nowadays with PFC front ends, there's no rectifier-reservoir electrolytic,
the PFC unit is essentially a boost converter, so the main electrolytic
would be about 450V.