Introduction: DIY Cold Cathode Lamp

Picture of DIY Cold Cathode Lamp

The Ultimate lamp for any die hard computer user. This is a pretty simple process to build and I was really satisfied with my end product.

Now like any computer mod project I do have a worklog posted here so you might find any questions you need already answered here..
DIY Cathode Worlog

Step 1: Supplies and the First Steps

Picture of Supplies and the First Steps

The material
- 3/4 inch Dowel
- Wood, I used 1x6
- Cathode and inverter
- CDs - preferably some economy ones with reflective layers on both sides.
- Acrylic tubing. Link here
- plexi glass
- PSU micro atx is preferable

below is the general prototype of what we're aiming for

First step is to cut your wood. You can cut this to any real length you want. I ended up making my box about 5.5 x 5.5 x 5.5 so make sure you cut all of your wood to fit which ever size you want. You will have three pieces the same because these will be the top and bottom of your base as well as the top piece of the lamp. Then you will have two pieces for the sides, and one piece for the back.

Step 2: Time for Paint

Picture of Time for Paint

You will want to additionally drill the holes for the cathode as well as the dowel. I used 3/4 inch dowel so I measured four equal lengths and cut them half way into the top piece of the lamp and the top piece of the lamp. Next I drilled a slightly larger hole in the center for the cathode. Don't drill it large enough for the cathode ends, just for the base, I'll explain this soon.

Once you finish some quick cuts you'll be ready for the paint. I went with all black, but go crazy; lime green or orange would probably look sweet in my opinion.

Step 3: It Starts Coming Together

Picture of It Starts Coming Together

Next we will put the cathode into the dowel. For this, I just took my dremel and a sanding bit and sanded down the end with the wire till it slid into the top piece of the lamp.

Next take your PSU. I ended up de soldering most the wires because they weren't needed. You will need to keep two ground wires, one 12v and the green wire going to the motherboard connector.

I also lucked out a bit on the PSU Fan, half of it was rounded so I took my hole saw and make an 80mm hole to mount it on the bottom piece. Then I cut a quick hole for the plug to fit into.

Step 4: Mounting the Plug

Picture of Mounting the Plug

now you can honestly use any plug you want. since this is a PSU going into the lap i took the plug from the PSU and mounted that in the back. It was an extremly clean looking option as well and if i trip on the cord the most it'll do is unplug the lamp instead of crash it to the floor.

Step 5: Mount the Psu

Picture of Mount the Psu

Then once this is done, you can mount your PSU. If you put the fan in the bottom find some quick spacers. This will only take a moment, and then secure it to the base of the bottom piece.

Step 6: The Face Plate

Picture of The Face Plate

Now for something fancy, you can lower your table saw and put a groove in the front of each of the side pieces of the base, once these two pieces are secured, you will have created one nice looking way to put in your front piece made from plexi.

In the plexi we'll be mounting the power switch and drilling some holes for ventilation. First to cut the plexi I recommend the crack and score method. Simply drag a razor blade in a straight line across the plexi 5-10 times depending on how sharp your tool is. I recommend using a straight edge. Then bend the plexi and it will snap along the guides you just cut.

Next drill a hole to mount the switch. And some more holes for ventilation. Make sure you have clean cuts, I recommend using a drill press to keep the holes extremely evenly spaced, a hand drill might wander and look bad.

Finally, to wire the switch, take the green wire from the Motherboard Connector and a ground wire and wire them to your switch. Once this is done, you'll have finished your front panel.

Step 7: Cutting Your Seperators

Picture of Cutting Your Seperators

All that is left is to wire your cathode inverter. I recommend wiring it instead of using a molex connector simply to keep the wires to a minimum. I mounted my cathode inverter to the wall; feel free to do the same.

Now it's time to cut your plexi tubing.

I found that the miter saw worked great for this. I cut my segments to ½inch but use what feels right. I ended up cutting 15 the first time, then going back and cutting 2 more to fill the extra lengths.

They'll look pretty messy and may have some ridges on them. I just smoothed them down on a belt sander then used my fingernails to break off the left over melted edges. When I finished, I had one really nice clean set of tubing segments.

Step 8: And We're Done

Picture of And We're Done

Now that we're this far it's just about done actually. Plug your cathode into the inverter and screw the top portion of the lap into the base. Plug in your PSU and watch it light up.

The light isn't bright enough to function as a normal lamp but it's pretty perfect as a bedside lamp or for decoration. I think it's a pretty cool use of old computer parts. Lol the PSU I used is a 120w PSU from an ancient eMachine computer, so don't be afraid to tear apart some ancient computers for this mod.

Now I admit I'm a bit tired so I feel like I probably missed some spots of this but I know I wrote enough for you to figure out the parts I missed but if you guys have any questions just let me know, I'd love a good discussion.


wilbster (author)2011-02-24

I know this is an old post, but instead of using a power supply couldn't you use a small power inverter? The lamp does output at 12 volts, right? I am only curious, because I am thinking about building one.

faceless105 (author)wilbster2011-02-25

Yeah that's correct. I forget where but somewhere in the responses I explained the reason for the PSU. This was built largely from scrap laying around and I had an ancient PC laying around that had a micro power supply, so I took the PSU out from that. It's a bit of overkill, but it also make the project free, lol

yeah, an inverter would do the trick, and the cathode does run on 12v.

MadScientist101 (author)2010-11-15

whats a psu?

maewert (author)MadScientist1012011-01-07

Power Supply Unit

pmilg (author)2007-05-14

I have well over 1500 AOL CD's any ideas what I can make with that many?

ReCreate (author)pmilg2009-06-07

Make an Exploding EPIC Tesla TURBINE! :P If you spin them at 22000 RPMS It Explodes! Plastic AOL Cd Shards everywhere!

Junkyard John (author)pmilg2008-08-17

A search on a site called might give you some ideas.

neotom666 (author)pmilg2008-02-10

send them back!

ARVash (author)pmilg2007-09-03

a small tent

!Andrew_Modder! (author)ARVash2007-10-04

a RICK rhombus. :-)

Kataze (author)pmilg2007-09-26

You could make the exact same number of any of the following items: Frisbees Shurikens Otherwise deadly spinning object Broken CDs Pocket Mirror XD

Shut Up Now (author)2008-12-31

OMG!! Computer Geeks using power tools!! i see TROUBLE!!!

faceless105 (author)Shut Up Now2009-01-02

lol it's all the rage. You'd be surprised to see what's out there, mine was a bit of a weekend hack project, but (and I warn you this isn't intended as a plug) I run a computer modding site,, and I'd bet money that 90% of the users have a dremel of their own.

liek I said, mine was a weekend project, if you wanna see some real works of tech art, here's a link to the case ranking page,

a lot of them have actually had magazine features :)

tbird45039 (author)2008-01-22

it would be easier to just use a 12 volt dc power suply. than craming that psu in there

iBurn (author)tbird450392008-12-22

His way's cheaper.

faceless105 (author)tbird450392008-01-22

I actually agree with you on this. The only reason I decided to go with the PSU was because I wanted to do this on the cheap. Everything used in this project was from parts laying around the house. It's actually mentioned in the comments that a PSU might be overkill, and really just about any power source is for something as small as a cathode, but this Micro PSU is only 120watts and was scrapped from and ancient eMachines computers. The spacing wasn't to bad though since it's a bit smaller then the diameter of a CD. If i do this again, theres a few things I'd do differently, but overall, I've been really pleased with the results.

digitizelife (author)2007-05-09

Oh man... this just gave me a great idea! Change the cathode to a UV cathode, swap out the CD's for hard drive platters, wire them up to a transformer, and you have yourself a DIY bug zapper! For the circuit, every other HD platter should be + and - so if something comes between any two plates, the circuit can arc through the object to complete the circuit. Two sets of coils, one heavy gauge surrounding a light gauge, with an AC pulse on the large coil, should induce a very high amp pulse into the smaller coil which is wired to the platters. If the platters come close enough, or something is placed in between them, an arc will occur. Someone more qualified with electronics could verifiy this and/or suggest an alternative

Xellers (author)digitizelife2008-12-07

Unfortunately that wont work for a few reasons: 1) UV light doesn't attract the types of bugs you want to zap (a mosquito will fly right by UV light without landing) 2) Bug zappers have two grids and the bug comes between them and completes the circuit. If you were to make each of the platters charged positively or negatively, then you would need some very high voltage. Unfortunately, you would have to worry about corona leakage, and the wires leading to each platter would have to have about 2 inches of insulation on them because high voltage jumps right through normal insulated wire. 3) Other than that (solvable problems), it would cost less to go out and buy a conventional bug zapper than to make one from this lamp.

iBurn (author)digitizelife2008-09-11

Sombody better post an instructable on that...

Yerboogieman (author)2008-08-17

i broke my Cathodes while camping, but, just the filament, not the casing, anything i could do with those?


inside glowey thing?

I didn't thing cold cathode tubes had filaments, Just my 2 cents, i'll check it out now


You sure the 'filament' is on the inside, mind taking a picture?

yep the light emitter.

But they look like they still work?

thats when they did work..:-(

can u take a pic of them now?

my dad brought his truck home, they're in his car.

has he got his car now?

there they are, thats my old bike, i posted pictures of what happened to it, my neighbor gave me a new bike, so i piecing this one for parts and putting them on that one, same style frame, different brand.

BTW, what type of battery did u use to power them?

duracell ultra alkaline

Hehe i thought u used a small SLA battery


Sealed Lead Acid, Like a car battery but are smaller

ajmontag (author)2008-04-14

its not properly grounded, as the metal casing of a PSU is added ground protection, i have used PSUs for a 12v power source, and chopped off a female molex (4 pin) connectior and ran wires off of that from the PSU, leaving the PSU untouched, just jumping the purple (?) and ground wires to get pwr. let me know if you want better details.

livesteamfan (author)ajmontag2008-08-12

Green to any ground wire.

UberPug (author)2007-12-24

i have an insect killing thing that looks exactly like that

hailtothkngbby (author)2007-11-23

Awesome Instructable! Great idea!

max302 (author)2007-09-23

Allow me to be skeptic. Isn't stuffing a PSU in a wooden box without any kind of cooling going to either brutally overheat and/or fry the power supply with prolongated use?

faceless105 (author)max3022007-09-23

I forgot to write about it but if you look in steps three and stepss 4, yo ucan see the fin and the hole in the base of the lamp. The front plexi has holes drilled in it for ventilation. Cooling hasn't been a problem yet and it's still running smooth :)

westfw (author)2007-05-09

Nice, but your power supply is like SEVERE overkill. (although, I'm not sure I can recommend anything that would be less expensive. :-( )

faceless105 (author)westfw2007-09-03

i agree on the overkill. but the psy was something very small i think either a 250 or very ancient 120w that i had laying around for years so there wasn't any use for it beyond something like this.

baki22 (author)2007-07-24

Hai all frnd, have any idea with cell phone lcd use as lamp thanks

domesticatedviking (author)2007-05-09

Looks a bit like a warp core off the NCC-1701D. Intentional?

lol completly unintentional but a pretty cool perk!

tspnews (author)2007-05-09

If one could make the 'seperators' out of something a little more 'slick' or 'slidable' so the cd's could spin freely you could ... Plut a slice in half of the cd and seperate the cd with another type of spacer. It would essentially turn the cd into a fan blade. You could then point the fan upward at the blades so they would spin.... fan might be too weak. Either way splitting the cds at one half and seperating them would allow the blue light to come off in varying directions and make a more interesting shine I think.

faceless105 (author)tspnews2007-05-09

i know just what your saying. And though i'm not sure yet on how i'd do the spinning i have been planning to make a second version of this lamp and i really like you fan blade idea. I think it'd look cool even if it wasn't spinning. I'm going to get started on this next one very soon. thanks for that great idea

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