# Bored at work; neat pictures follow. *New Pics Added 3-13-07!*



## DNova (Feb 19, 2007)

Thought you guys might like to see a couple of interesting pictures I took last Friday and today.

These first pictures are from a standard long-life 60 watt light bulb. It came with my house and was in operation nearly 24/7 for at least 4 years. The following three images were made with a FE-SEM (Field Emission Scanning Electron Microscope). Please do not republish any of the images in this post. 






This is one of the very thin filament supports (not electrified) which helps to hold up the filament. It is made of pure molybdenum which is a high-melting-point metal. This is a clean area of the support





Here's the same exact wire, but in an area where evaporated tungsten condensed. When metals evaporate in high vacuum, they tend to leave a very thin uniform film, but under (relatively) high pressures in a modern incandescent bulb, they leave a cloudy/fuzzy mess like you see here. The fuzzy stuff is of course tungsten. 





Here's a highly magnified (5,000x) view of the evaporated tungsten fluff. 


Next I decided to take a look at the filament of a Mag Solitaire (single cell) flashlight bulb. These are tiny bulbs if you aren't aware of them. The following two images were taken on a Nikon Stereoscope using reflected light and a 4mp digital camera attachment. 





This is the filament without any power through it. The total distance between the two posts is approximately 1.5mm. The length of the coiled filament is less than 1mm. I don't know what the total uncoiled length would be. 





And here it is in operation with an aging alkaline AAA. You can notice how much of the filament is NOT incandescing because of heat loss to the supports. Probably a bit less than 500 microns (.5mm) of the filament is incandescing. Perhaps a bit more would with a stronger battery. 


That's it for now. I hope you found these at least a little interesting.


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## Ra (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Nope !!, Not a little interesting,,

I found them very interesting !! :goodjob:

If you are bored in the future: Maybe you can make some pictures of a new halogen-filament and one at half-age ?? Would also be very interesting !!


Regards,

Ra.


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## atm (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Awesome, thanks DNova, and welcome to CPF!


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## Manzerick (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Very interesting!


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## abvidledUK (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Perhaps put your CPF name across the photo's to discourage copying ?


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## greenlight (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Sweet post.

It would be cool to see what different flashlight finishes look like up close.


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## DNova (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*



Ra said:


> Nope !!, Not a little interesting,,
> 
> I found them very interesting !! :goodjob:
> 
> ...




I'm glad you found them interesting 

I am actually planning to take some SEM images of unused filaments versus heavily used filaments of the exact same bulb at some point in the future. 

The differences will be very interesting for sure. The problem is finding a bunch of pairs of identical bulbs, one being burned out or heavily used, the other being unused. 

If anyone has such pairs to donate to the cause that would be great.


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## DNova (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*



greenlight said:


> Sweet post.
> 
> It would be cool to see what different flashlight finishes look like up close.


 Doing this would be very easy, but I can't accomodate large samples. I'd have to cut them up unless it was a really small flashlight with no electronics (or removable electronics). If anyone wants to send things for analysis I'd be happy to do it. I can identify alloys and elemental composition too.


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## IsaacHayes (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

I love it!!! Thanks!


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## Christoph (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

cool pics:wow: send more next time you get bored.


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## molite (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Very nice.
I hope you continue to get free time at work.
More pic's of anything light related would be very cool.
What other cool toys do you have at work?


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## 65535 (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Very awsome.


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## DNova (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*



molite said:


> Very nice.
> I hope you continue to get free time at work.
> More pic's of anything light related would be very cool.
> What other cool toys do you have at work?



Thank you and everyone for your comments. 

Don't worry about me getting free time at work, I promise I have plenty  

I'm going to be taking some pictures of the truly tiny incandescent bulbs that old digital watches used as a backlight. I have a few examples, and man, they must be the smallest light bulbs ever made. But I only have one of them here today, so I'm going to wait until I remember to bring them all in. 

If you have any specific requests I can try to fulfil them. I have access to a ready supply of liquid nitrogen and I'm thinking about breaking open a new light bulb and turning on the filament under there to see what happens. I think it'll just conduct too much electricity and not light up, so I'm going to use a fused test rig with a dead-man's switch to try it out. We'll see I guess.

Let me know if you have any ideas/requests.


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## Mark_Larson (Feb 19, 2007)

*Re: Bored at work; neat pictures follow.*

Wow, awesome photos. And I definitely remember those tiny bulbs that were used before LED/EL lighting. Wow, these photos are really awesome.


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## Mike V (Feb 21, 2007)

*Re: Bored at work; neat pictures follow.*

Wow.

Amazing. Thanks for posting these.


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## DaFABRICATA (Feb 21, 2007)

*Re: Bored at work; neat pictures follow.*

I close up of an LED emitter just barely on would be really cool!


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## thesurefire (Feb 21, 2007)

*Re: Bored at work; neat pictures follow.*

Those are really cool pictures. 



DaFABRICATA said:


> I close up of an LED emitter just barely on would be really cool!



I would also love to see that.


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## Thujone (Feb 21, 2007)

*Re: Bored at work; neat pictures follow.*



DNova said:


> Doing this would be very easy, but I can't accomodate large samples. I'd have to cut them up unless it was a really small flashlight with no electronics (or removable electronics). If anyone wants to send things for analysis I'd be happy to do it. I can identify alloys and elemental composition too.



Possibly you could just use the tailcap of a few flashlights if they would be small enough for you.

Thanks for the great pics.


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## DNova (Feb 21, 2007)

*Re: Bored at work; neat pictures follow.*

Some tailcaps would probably exceed my height restriction, it all depends on their geometry. I could figure out the max dimensions if there's enough interest. 

As for a barely-emitting LED die, I'll bring in a few monochrome LEDs and hopefully get some neat pictures for you. Probably Friday


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## DNova (Feb 23, 2007)

*Re: Bored at work; neat pictures follow.*

I packed up a bunch of stuff last night to bring in today for an LED photo shoot. Luckily, I grabbed more than the first LED that looked suitable out of my pile, because it turns out that one was DEFECTIVE!! Anyways, here are the pics with some annotations. Again, please do not republish these in any way. If you want to use them just ask. These are all optical microscopy photographs. 





Oops, the LED factory failed to properly attach the ball bond to the die! Or it detached before it was encapsulated in plastic. Either way, this LED never had a chance. At the top is a reflection of the die and wire due to the shape of the LED package. 





Another LED (this is the LED used for the rest of these images), no power, low magnification. 





Higher magnification of the same LED, with more light shining on it. It still has no power. The die itself is red and all the red light in this picture is merely reflecting off the die. 





Low magnification with 5.2v + 30,000 ohms (less than .2mA through the LED). 





Higher magnification with the same power parameters. 





Here it is without any ambient light, and only 1,000 ohms resistance. In all these pictures the red ring around the die is just from the metal reflector cup, and is not part of the emitting surface. 


Hope you guys like this batch of pictures! It was a lot harder to get decent pictures of these LEDs than I thought it would be. I played around for a while with exposure settings, positioning, and external lighting. Let me know what you think!


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## DaFABRICATA (Feb 23, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

YOU ARE THE MAN!!!!!


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## Illum (Feb 23, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

you have this kind of technology at your work place????!!!
how can you be BORED?

oo: theres so many things worthy of being seen with that microscope of yours....you can literally find the flea on the flea on your dog...provided you have one...

where do you work?


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## EngrPaul (Feb 23, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Cool. (I was hoping it wasn't photocopies of your butt.)


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## DNova (Feb 23, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Thanks 

Here's the bigger version of my new avatar for CPF:


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## [email protected] (Feb 23, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Impressive pics!  :goodjob:


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## molite (Mar 12, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Awsome again!
A newbie with something to offer CPF and Wow the senior members!
Unlike me, sucking up information and asking dumb questions.
You really make all us other newbies look bad.
Keep the pic's coming.
You've done Ican and Led so now a lazer?


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## liveforphysics (Mar 12, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Outstanding!

These are some of the most outstanding pictures I've ever seen!

Thank you for shareing these amazing photos with us!


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## Manzerick (Mar 13, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Wow!!


Very nice pics!!!


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## 65535 (Mar 13, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

I would love to see the surface of a HID bulb where the arc is formed new and after a few hours and after death.


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## greenlight (Mar 13, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Must be some boring job!!!

sweet avatar, too.


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## DNova (Mar 13, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

Thanks guys! I really appreciate your comments. 

molite - I wouldn't really be able to do that unfortunately. 

65535 - What kind of HID lamp? The outer surface will just be quartz or alumina; nothing interesting. The inner surfaces could be fairly interesting due to thermal etching and other chemical attacks on the inside of the bulb surface. That's something I'll think about but I don't have access to a set of new/used/dead of the same lamp (or at least same type) at the moment. And if you're talking flashlight metal halide HID lamps, forget it! Unless you want to send me $200 worth of working HID lamps and a broken one to boot!  But their bigger cousins are the same thing and should be just as interesting anyways.


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## DNova (Mar 13, 2007)

*Re: Bored at work; neat pictures follow. *New Pics Added**

This next set of pictures is from a car headlight lamp assembly. This particular lamp has two filaments, one for high beams and one for low beams. They are taken out of service when the low-beam filament dies, but the high-beam filaments are generally intact. I did this today as part of my endeavor to study incadendescent lamp failure. At this point, I'm still learning how best to break them open! These have really thick quartz bulbs which put up with some serious blows from a hammer and chisel. 





This is the assembly I used today before I abused it further. The primary filament is, for the most part, missing. You can notice some little spikey re-condensed tungsten crystals on the supports. More of those later. Actually at this point I already broke the tip off the bulb and extracted the filament bits that way, to ensure they wouldn't get damaged further. 

Then, I couldn't resist the temptation. With a 0-12.5VAC variac, I just *had* to run the high-beam filament. Remember, at this point, the tip of the bulb is broken off, so all the nice protective gases and halogens are gone and replaced with plain old-fashioned air! 

I ran the filament at about 3.5VAC and it lasted around 15 seconds, glowing red hot and clouding up the bulb with yellowish-white and bluish-white tungsten oxides. It formed some wonderful clouds of oxide crystals on the filament, on the adjacent bit of filament, the filament supports, etc. It was really, really cool. The following pictures just don't do it justice, unfortunately. It looks a lot better looking at it live through the microscope. 





Here you can see the now toasted filament and the amazing crystal growths. What remains of the low-beam filament is coated in a very smooth cloud-like layer of oxide crystals. The upper portions of the burned filament are covered in courser yellow oxide crystals. The whole bulb envelope is covered in a swirly pattern. This picture was taken with the bulb intact still (for the most part). 





Here are the two filaments after I wrestled with the quartz bulb and got them freed. Unfortunately most of the crystal growth has been disturbed and is lost . However, it did reveal some brilliant blue shades on the low-beam filament that weren't there before. Those blues are pretty close to how they look in real life, but in real life they are much more vibrant! See those little spikes in the upper right support, near the end of it?





Re-condensed tungsten metal crystals! These formed during normal use of the headlight. They're relatively tough little crystals, bonded fairly strongly to their substrate, so they survived my beatings. They will hopefully look really cool in the SEM later. 





Here's another view when the bulb was still intact of the burned filament and the amazing oxide coating on the low-beam fragment. Hmm, there's something interesting on that burned filament.....





Wow! Check out those tungsten oxide crystals! They're "huge!" I really wish they would have come out better, but I took these pictures through the bulb glass which really complicates focusing. Once I broke the bulb, those crystals had fallen off, never to be seen again. Oh well, it was a learning experience all the same! 





Crop of the above image emphasizing the oxide crystals. 



I have yet to check out any of these things in the SEM. When I do that I expect some more amazing images. This sample will also help me to learn what the difference is between a mechanical break when filament is on vs filament off (from the low-beam filament which was broken from use, and then further broken at other weak points by my hammering).

I know at least icebreak will like these; hopefully I'm not boring the rest of you


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## Gunner12 (Mar 13, 2007)

Boring!, Quite the opposite, I'm fascinated by your pictures.

Keep up the good work


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## Icebreak (Mar 13, 2007)

Now, _that _is pretty freaking cool!


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## Russianesq (Mar 13, 2007)

wow


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## 65535 (Mar 15, 2007)

DNova, yes the arc surface, the fused quartz envelope is a rather pooring high transmission surface, with backlighting you wouldn't even see it, as for cutting open bulbs, get yourself a dremel with a diamond shaping and cutting wheel, it'll zp right through glass, just make sure you don't gunk it up with soft metals, they tend to fill the crevices and ruin the effectiveness of the diamond sintering.


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## DNova (Mar 15, 2007)

65535 said:


> DNova, yes the arc surface, the fused quartz envelope is a rather pooring high transmission surface, with backlighting you wouldn't even see it, as for cutting open bulbs, get yourself a dremel with a diamond shaping and cutting wheel, it'll zp right through glass, just make sure you don't gunk it up with soft metals, they tend to fill the crevices and ruin the effectiveness of the diamond sintering.


 I wouldn't use a dremel with a cutoff wheel for HID bulbs due to the toxic and highly corrosive chemicals inside. Even with non-toxic lamps like halogens and standard incandescents, I'd have to do it outside or under a really good fume hood. Glass dust + lungs = silicosis. Plus there's the risk of explosion for high pressure bulbs. I will probably have to try that out soon though, as it may be the best way to preserve delicate structures in the lamp.


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## 65535 (Mar 15, 2007)

I have cut a few glass bubl envelopes with a dremel and it works pretty well, just make sure you grind it slowly, you could try using a water drip on it to keep the dust suspended in the water, just don't get the dremel wet.


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## DNova (Mar 15, 2007)

65535 said:


> I have cut a few glass bubl envelopes with a dremel and it works pretty well, just make sure you grind it slowly, you could try using a water drip on it to keep the dust suspended in the water, just don't get the dremel wet.


 How much are those cutoff wheels? I've wanted a dremel for so long but kept resisting them, but I think this is going to get me to take the plunge very soon. I at least have access to one that I can borrow for now, but I still need my own attachments.


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