Picture of Take apart a Compact Fluorescent Bulb
Compact Fluorescent Light Bulbs (CFLs) are increasingly popular as a way to save some energy. Eventually, they do burn out. Some seem to burn out annoyingly quickly :-( Even if not burnt out, CFL bulbs have become very cheap, especially if you live in an area where they get subsidized by your local electrical utility.

Are there any hobbyist usable electronics parts inside a CFL? How do they work, anyway? And when they burn out, why have they burnt out?

Let's take some apart and see!

(This Photo by PiccoloNamek from Wikipedia. Hopefully this is sufficient to meet the requirements of the license; I didn't have my lawyer review the Gnu Free Documentation License)
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Step 1: Take it Apart 1: cut a pry-slot

Most of the CFLs I've seen have a seam where they can be pried apart without too much difficulty. Sometimes the seam is glued or "welded" together, other times it's just where two pieces have been "press fit" together.

Unfortunately, even if only press-fit, the two pieces are usually too securely attached to just pry them apart with your hands, if only because one of the halves has only the glass tube to get a grip on. Sometimes the joining seam is loose and/or large enough to fit in a flat-blade screwdriver, but it is easiest (assuming you don't want to re-use the bulb casing) to cut a shallow slot at the seam with a hacksaw. Just hold the housing securely (in a small vise as pictured, or not), and saw a slot just barely through the casing - about 4mm.


Try REALLY hard not to break the glass fluorescent tube. Aside from sharp edges, fluorescent lights contain phosphors of unknown and possibly dangerous composition, and a small amount of mercury that you'd rather not have released in your home or workshop.
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pavelanni made it!16 days ago
I used a small hand saw before prying the bulb with a screw driver. The rest was easy.
Akshat Ag1 month ago
This is very usefull for my project
laci376 years ago
Mercury is very toxic, but its not so dangerous in small amounts like this if there is no strong airflow it stays near the ground.
dawp laci375 years ago
I think some concern borders on hysteria and lack of common sense. If i should accidentally drop a fever thermometer (there i really dated myself) i don't think i would call the men in the space suits. The XEROX company tried to make a dental imaging machine based on xerographic principals. They found out that the residual mercury in the dentist's carpets "poisoned" the drum. The project was eventually dropped. The same also is said to hold true if somebody breaks a fluorescent tube in a room where a XEROX machine is installed. For us hoomons It is the mercury compounds that are dangerous and that is what accumulates in fish organs, etc. Mercuric chloride is a deadly poison. Years ago our chemistry teachers in high school would pass liquid mercury around the classroom. Now they fire a teacher if he even has a vial of the stuff.
webgiant dawp1 year ago
Concern about mercury in CFLs does border on hysteria. You could spend months shattering 100,000 CFLs in one spot on your carpet, and once you had finished shattering the 100,000th CFL, you would finally have some cause for worry about mercury poisoning as an adult.

The bigger problem with CFLs, where the hysteria is justified, is pets, children, and the elderly. Mercury affects these groups much more than adults, and children and pets might lick the carpet. So if you have a household with no pets or children, then there's not much to worry about with breaking a CFL.

For those who worry about breaking them anyway, here;s a simple comment: think about the number of times you have ever broken a standard incandescent light bulb. Now divide that number by 10. Since CFLs generally last ten times longer than incandescents, this is the number of times you will break a CFL. Chances are this new number will be less than zero.
Yes, I remember being allowed to roll it around on our hands - that's really going back some!! I'm almost 60 - phew!!
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Mercury is dangerous if you work with it for years, becasue it won't leave the body
That's right, it's an accumulative poison. The odd amount won't kill you though, the same can be said for radiation -- within reason Rumour has it that in the past it was used as to "cure" many ailments and made your teeth both translucent and green, wish I could remember where I read that.
People in the Victorian era put Thorium and other radioactive things into toothpaste and cosmetics, they thought that anything as energetic as radiation would have to be good for the body. Mmmmmm...Thorium.
westfw (author)  SKYNET 2.05 years ago
Isn't there still thorium in gas lantern "mantels" ? And don't forget that lovely "uranium glass" and "Fiestaware" pottery containing uranium and produced up through the early 1970s... Of course, the resulting radiation poisoning wiped out the entire American upper middle class during that time period. So sad; they should have known better!
Actually uranium glass may still be made, any radioactivity is contained within the glass. It occurs mostly in the green glasswares you see, though many other doping compounds (colourants) are used. As for flame-mantels (I know the ones you mean) i'm reasonably sure they aren't made any with thorium any more, though I could well be wrong, it wouldn't be the first time!
Peeet xerxesx205 years ago
Radioactivity is definitely NOT contained by glass. The uranium itself is but not the radioactivity. Danger from radioactivity is measured by 3 factors: level of dose, proximity and duration. Some old wrist watches had alarmingly high levels of radioactivity as tested by my scientist brother. This is of concern as proximity is obviously very close and duration of exposure is potentially very long. Old green transparent glass can be radioactive.
xerxesx20 Peeet5 years ago
Thanks for filling me in there! I suppose the level of (alpha is stopped by pretty much everything that's thicker than paper, so we'll un-complicate things and forget about alpha for now) gamma, or beta recieved depends upon the thickness of said insulating material also how long the person is within range/proximity to the not-very-well entombed source. Interesting that old watches and some glasswares are still radioactive, "uber" long half life I suppose -- difficult to decide how long the half life would be without knowing exactly what radioisotope of uranium it is. I have seen recently a boost in sales of a small transparent quartz/glass/plastic chamber that has a minute amount of tritium gas inside, a so-called "long life" light source without a switch. They are generally traded as keyrings, but are quite costly. £6-8. ($10-15) I was considering buying one, but I have to be careful of my money at the moment, Leadpumper is becoming rather in need of a good service/rebuild. So that's got most of my dosh for the minute!
dawp xerxesx205 years ago
Hi: Over 10 years ago i got a Mb Microtek watch. It had tritium numerals and hands. It glowed beautifully in the dark; try it in a cave when they turn out all the lights. The guides get mad about that:) In any case, i haven't died of radiation poisoning and it is still glowing in the dark, but not as bright as new. The half life of tritium is around 10 years. The only watch i know of that currently advertises these lights is in Cabela's catalog. I forget the exact name of it. People and regulatory agencies have a fear of the N word and it is generally difficult to get light capsules. In space they are called "Beta Lghts". I think they have also been used in nautical buoys.
Peeet dawp5 years ago
"i haven't died of radiation poisoning" I'm glad to hear it. There is always a chance that some people will be unaffected by general risks. The fact is that less exposure (which is determined by intensity, proximity & duration) to radiation equals less risk of cell mutation. It is not an irrational fear by regulatory bodies just to make life difficult for us. Some smokers live to ripe old ages, but the vast majority have health effects.
DIY-Guy Peeet3 years ago
On the original thread:
Kudos to WestFW for a nice -ible on CFL parts.

On the divergent thread:
Tritium is fine IF it's encased safely. Watches with tritium hands have been designed to keep it inside. Regulatory agencies are not always driven by science but often are driven by public outcry and ignorance. Ask a n* physicist who works with those things and they'll tell you the gas lantern mantles and watch hands scare is pretty much just that, scare tactics. Moral- don't grind up any of those things and eat them.

What a great spelunking tool to bring on the tour, a watch face that won't stop glowing no matter how dark it is or how long it has been in the dark!
westfw (author)  xerxesx205 years ago
Don't forget that common potassium is radioactive too.
Surely not all forms of it are? There's more than I thought: "There are 24 known isotopes of potassium." -- According to Wikipedia (I'm too tired for "proper" research. lol It's also got a Moh's hardness of just .4 ! Talc(um powder -- it's the same stuff at the end of the day, just smashed and crushed up.) is 1.
Common potassium(atomic weigth 39) is NOT radioactive. About the hardness of the alkali metals, they are very soft, I have cut sodium with a knife, and it's said that potassium is even softer. But aren't we a little off-topic?
Thanks for that,and yup, off topic happens to be what makes the world go round. A little disorder is good for the soul, a lot like genuine Chinese chicken noodle soup. "A little nonsense now and then, is cherished by the wisest men..." :-)
I remember the infamous fiesta ware. My grandmother kept a set in here bunker-like basement, on day my uncle took a Geiger counter down there to see if we had a radon problem, and the thing crackled away when he set it on the bow of fiesta wear. The offending box was promptly encased in concrete.
Her* not here
Yes, indeedy. Watchfaces were often treated with tritium, the "tritium girls" as they were known (I think that's right anyways)(the lasses who applied it to the hands and faces of said watches) didn't live long and sometimes put it onto their hands or teeth as a practical joke. Mercury is still poisoning people today in one of OSRAM's facilities in China -- I read about this recently in the press -- though you can't always believe what you read!
Tritium is a more fun isotope of hydrogen. Not only does i still go boom, it's also radio-active! And it was radium on the watch faces. They were tought to put the brush in their mouth to straighten it out for more delicate painting. Mmm, radium.
I often wondered about the Tritium. The Night Sites on my work gun, a Sig Sauer p220, are manufactured by Trigicon and use Tritium as it's power source. They are encased in metal and what appears to a thick plastic dot (maybe glass) I don't know how long these sights have been in production or their intended shelf life but I was issued this firearm about 5 years ago and they still glow very brightly in low light situations! I suppose it is like everything else though, they sell it and say it is safe but 20 years later they will tell you it causes cancer or something! I know we strayed off topic a bit but it is interesting anyway. A true conversation piece of an Instructable!
rexmo 1BigKid5 years ago
tritium is not nearly as dangerous as radium and has a much shorter half life
rexmo xerxesx205 years ago
it was not tritium, it was Radium.
Watch faces were treated with radium not tritium and they were "radium girls".
Aye, thankyou. I realised my mistake after posting, it just didn't sound right if you know what I mean. :-) Hence.. radium jaw -- NOT tritium jaw. lol
Since we are on the subject of toxin's substances and unseen radiation has any ever done a study of the effects of WiFi `s . I think that someone should see if pumping all those 0``s and 1 `s into our environment have any ill effects
BOOM5601 sml1565 years ago
The 0's are not a concern. It's the deadly 1's we gotta watch out for.
True. Also it's not that much mercury. There are higher level of mercury it some fish.
junits15 laci376 years ago
u do realize that the amount of murcury in one of these is not nearly enough to kill you, it wont even make u feel sick
 are you super sure? I just broke one and I'm freaking out

read below
Peeet junits155 years ago
Not the point--heavy metal contamination is cumulative. It accumulates in the body. If you eat shark too many times a week it can be hazardous for the same reason--them being near the top of the food chain we get the end results of their build-up. There are a lot of hazardous inputs that won't make you feel sick immediately.
junits15 Peeet5 years ago
oh i didn't realize it was accumulitive
dillonxti1 year ago
to get mine apart I just whack the seam with a small hammer
james346022 years ago
I use this circuit for my flyback transformer driver
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