Why do fluorescent Bulbs (CFL) last only a few months?

[ChuckG]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

There was a blog article in one of the EE trade rags (Electronic Design, EDN, EETimes?) not too long ago about this subject.

One of the things that's often overlooked is that most consumer-grade CFL units are made to be burned base-down. The electronics produce quite a bit of heat and burning in the inverted position just aggravates matters. Burn one in an inverted recessed can fixture and things get even worse.

Duty cycle and low-temp operation, as others have mentioned, are also major life factors.

[linuxguru]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

The electronics in the cheapo CFLs usually fails before the tubes. Check out the two half-bridge caps - usually about 2.2uF, 250V. If you put good caps there, a CFL can last years. Crap caps, and they blow in a few months, taking the switchers, etc. with them. They also dislike moisture, so if you're inclined to mod it, pot the electronics with some hot-melt glue after you've modded it.

[PCBONEZ]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

I've never thought about modding light bulbs. Kind of a strange thought actually.

http://www.elektor.com/news/led-tube..._campaign=news

[bgavin]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

My Dad solved the blown bulb thing back in the 50s.
He took one of those Y-splitter socket adapters that run two bulbs, and rewired it to series.

Each of the two lamps ran at half voltage.
The one he had in the well house ran from the time I was a kid until I buried him 45 years later. He had another in the ham shack in his basement. It ran just as long.

[linuxguru]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

LED flourescent tube replacement for $306 each? It's not there yet, but maybe at $10...

[PCBONEZ]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

DUH!
I wasn't suggesting anyone buy them.
Just showing what they're working on.

[japlytic]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

Shock CFL recall!

http://www.youtube.com/watch?v=X29uZdeq92U

[stj]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

i'v used the led tubes, the 2foot is about $70
you just need to know where to look.

as for making incan's last, you need to use a zero-crossing switch that's all.
one electronics mag many years ago published a simple circuit to build into the back of light-switches.

or you could use an electronic dimmer now.

[smason]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

Yeah, I can tell your cat isn't having any problems either.

What cat? That's actually him.

I agree, Toast. We did the same thing as kids, heck the science teacher passed it around. Nnnn othing wrong wwwwith me either...

[PCBONEZ]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

Not that cat, the 'Bill the Cat' twin with the machine gun.

[monkeynut]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

I've had an OSRAM 100w equivalent CFL in my room for at least five years and it's still very bright. It's used about 6 hours a day overall. This bulb was about £10 and is still just as good as new, apart from the plastic is going a tad yellow. I suppose you get what you pay for.

Interestingly it's made in Germany, not China.

[Lenny_Nero]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

The good CFL seem to last much better, we have some that are at 5 years plus, but they just get switched on and left for the evening. As said no good for a place you switch them on for 5 mins at a time. Also they give ok light, but the guides given are too low, I just get the next one up from the given equivalent, and have no problems with light. Also the way they burn down is to loose light output, most of the people I hear saying that they dont give enuff light are running old bulbs, or have something like an 8w or 11w CFL where they would need/use 100 plus watt incandescent.

When my mum and dad moved into their house (1981) there were/are two 3 foot tubes in the kitchen (of what age I dont know) only one has been changed, by me, a few months ago, the other is still working fine, but it has been run all of the time for the last 8 plus years.

[delaware74b]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

Lenny Nero, leaving all types of fluorescent lamps on will increase their life span. It's common to get 36,000 hours out of lamps in an installation where they are operated continuously or a minimum of 12 hours per start. The lamps contain a filament at each end of the lamp and every start burns off a small amount of that filament. The filament is usually deposited on the inner wall of the lamp, causing the typical blackening. It is true the name-branded cfl's usually do last longer then the no-name ones.

[starfury1]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

Hi All
well didnt read it all but yep why don't they last as long as they are suppose to or so short a time..probably cause they are made of junk as was pointed out,
dont like a lot of switching too...
I have a stuffed one that I know was used for years (like 10 or possibly more) in a work kitchen but that was like $25 AU at the time it was bought... when they were a new thing

on the green question well again here they banned the old faithful incandescent so we are forced to use them, one argument I hear was like OK how much resources & processed materials etc does it take to make one compared to the old faithful
(which can be made to last a longer then they do... )
obviously more

so well for green these things are going to have to last for years to make them worth while and in fact we got more likely the reverse situation happening and why cause its all about the $$$ and sadly for the environment $ is whats going to screw it.
Why? cause its the man in the white suit scenario if you want to go green and that dont work for making a buck
consume less recycle more
its the consume less part that dont work for the $$$

but now like Cal
oh gee we got to get rid of that in an eviormentally friendly way
..no worries sting the customer with a dispose tax...
so at the end of the DAY we get screwed a lot more green to go green ..go figure

OH anyone feel like building a coal burner power station in oz I need cheaper electricity...this going green is sending me bankrupt :P

anyway just my 2c worth

[kc8adu]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

Hi All
well didnt read it all but yep why don't they last as long as they are suppose to or so short a time..probably cause they are made of junk as was pointed out,
dont like a lot of switching too...
I have a stuffed one that I know was used for years (like 10 or possibly more) in a work kitchen but that was like $25 AU at the time it was bought... when they were a new thing

on the green question well again here they banned the old faithful incandescent so we are forced to use them, one argument I hear was like OK how much resources & processed materials etc does it take to make one compared to the old faithful
(which can be made to last a longer then they do... )

sure the incandescent bulb can be made to last longer but at the expense of efficiancy.
an example is traffic signal bulbs.

[Scenic]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

At a building I used to work, someone had the idea to replace the standard starter with electronic ones. Usually a good idea, because they prolong the life of the light source and shut down defective light sources without blinking, saving maintenance. However the person choosing starter bought the cheapest available, Pulsestarter, at about 25% of the price of the two most common brands in Norway. What happened was that the starters started to fail before the good quality light sources. I don't think anyone cared to find out why the starters failed, but one I pulled apart used Suntan capacitors, if that can give any indication of component quality.

suntan? suntan. sun-tan caps for light bulbs!
i guess i found out how those crapcap manufacturers come up with their strange names..

sure the incandescent bulb can be made to last longer but at the expense of efficiancy.
an example is traffic signal bulbs.

or this one..
http://www.dailymail.co.uk/news/arti...lightbulb.html

[japlytic]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

The use of substandard CFLs can cost you money:
http://www.youtube.com/watch?v=u7mhWU_K7TQ

[stj]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

some cheap cfl's fail because the heaters go open circuit from being run continuously.

i know this because i'v been doing some autopsy's on them recently to recover the cases for something.

[smason]

Re: Why do fluorescent Bulbs (CFL) last only a few months?

I have a house full of Philips Marathon CFLs 2 years and only 1 has failed, and it was mounted upside down in a bare basement socket.