Re: Stopping Lights from Strobing

Harvey White
 

On Sun, 15 Jul 2018 08:54:08 +0000 (UTC), you wrote:

I made a fixture years ago for working under the car at night.  Three 150W bulbs in ceramic bases.  Not only could I see everything, but it warmed up the carport in the winter!    
CFLs are terrible.  I do have some that have lasted a while, but most last about a year.  I have incandescents that I haven't changed in ten+ years.  One in a hallway is about 20 years old and still kicking.
The failure mechanism in an incandescent light is mainly related to
filament thinning as the tungsten evaporates slowly and is deposited
on the inside of the glass bulb. Eventually, the inrush current gets
that small higher resistance point up to where the filament just plain
melts.

For incandescents, the lifetime is related to the rated voltage to
applied voltage ratio. 10% more voltage, from what I've heard,
results in almost 1/10 the lifetime. 10% less, and you have a very
long life bulb. For those with choices, and 120 volts household (mine
is 122 to 123), use a 130 volt bulb to get very long life.

Now for CCFL and LEDS, well, no filament, so the failure mechanism (at
least completely for LEDS) is component failure generally due to
temperature (I ignore voltage spikes here). Some of the LED lamps get
rather hot, depending on whether the LED or the control electronics is
the problem heat source. We know what that does to the electronics.
Cheaply made is also a factor, of course. Anything in the commodity
market is generally made for lowest cost to manufacture traded off
against an acceptable failure/return rate.

There are carbon filament light bulbs (low temperature) that have been
operating for over fifty years. I have a fiber optics light source
for a microscope that has been working for several years (not
continuous), and is permanently set on the "LOW" setting.

Harvey


-Dave

From: stefan_trethan <stefan_trethan@...>
To: TekScopes@groups.io
Sent: Saturday, July 14, 2018 11:03 PM
Subject: Re: [TekScopes] Stopping Lights from Strobing

According to an EU study, which assumed only 20% recycling, CFLs still
release less mercury than incandescent bulbs, if you account for the
mercury emissions by coal power plants which made up about 30% of
power generation at the time.

But luckily we have LED now, those CFLs really sucked.

I too have a cache of incandescent bulbs. Many stupid people like
myself bought a bunch when their sale was about to be restricted and
prices were already high. Unlikely I will ever use them, already you
see fixtures that aren't designed thermally for any more than 20W or
so.

ST

On Sun, Jul 15, 2018 at 7:25 AM, musicamex <musicamex@...> wrote:
  I wonder how
much mercury based lighting actually is disposed of without release of the
Hg into the environment.. I do have a small cache of filament bulbs, mainly
for current limiters.  I'm sure enough to outlast me.

Russ






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