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USB Cold Cathode?

Hi, I have been wondering about creating an ambient glow around the back of my iMac with a usb powered cold cathode light or led strip, could anyone help me with this? i would prefer a prefab solution that doesn't involve much soldering or modification of hardware but that stuff is not necessarily beyond my skill level. (and sorry if this is in the wrong place, its my first post :P )

Topic by awesomesquared    |  last reply

Anode and cathode metals? (For electrolysis)

I want to seperate some water to get Hydrogen to play with, so I made a little electrolysis device with a 12v power supply. The only problem is that I have no idea what to use as the anode and cathode! Could I just use screws? Or pennies or something?

Topic by Login258    |  last reply

Cathode Ray Tube and Cloud Chamber Combined - Possible?

Is it possible to build a cathode ray tube and observe the path of electrons in a combined (or linked) cloud chamber? I would want to apply a uniform magnetic field to the cloud chamber but not the CRT so that electrons travel in a straight line into the chamber and are subsequently deflected. Oh, and ideally using materials that were available in 1917! Thanks in advance.

Topic by boroman    |  last reply

I dont really want to buy a $130ground fx neon kit for my car, can i use cold cathodes for the underside?

The ground fx kit for my car would be around $130 bucks. Cold cathodes go for $6 on ebay. Can i use 6 cold cathodes and wire it into my car?

Question by XxtwistedxX    |  last reply

Would this battery work?

I want to make a compact battery, I need it to generate as many volts possible. The battery materials are the following: Anode: Zinc Cathode: Steel Electrolyte: Sulfuric Acid Is that the optimal anode and cathode I can use to get most volts out of it?

Question by Nitr0    |  last reply

Cold Cathode Tube Voltage and Speaker Questions

My brother has some cold cathode tubes, some about 6" long, some about 12" or more. I was thinking of hooking them up to my bike, as shown in one of the great Instructables here, but I wasn't sure of the voltage. I don't want to over-power the tube, and bust it. Plus, the two wires coming out of it are in this black connector, so I don't know which is positive or negative. The tubes put out blue light, if that makes any difference.I have an old sports radio, which works pretty good and could be turned up really loud. I desoldered the speaker, and hooked it up to a pair of wires coming from a head phone jack. I plugged it into my iPod, expecting loudness, but no - I had to hold it up to my ear, on full volume, to hear it. Is it because the iPod isn't outputting as much voltage or current to the speaker as my radio was? The radio used 3 AA. I really wanted a portable speaker that actually put out big sound, so I didn't have to have those buds stuck in my ear.Thanks y'all!

Topic by Bran    |  last reply

Anyone savvy with Air Electrodes??? Thanks! =)

I'm posting this after having googled, of course...I work with DIY fuel cells using off the wall fuels. By far, the most expensive component of my FCs is the Air Electrode which I purchase from Electric Fuel Ltd. in Israel. The material was invented in 2008 (as far as I know) and EF were the ones who bought the patent (according to the inventor himself...sorry but his name eludes me). Anyhow, I was wondering if anyone knows how to make good air electrodes. Something that would give me at least a vold in reference to the SHE (V=0) and a current density of up to a few hundred mA/aq cm...The stuff is basically this, from the electrolyte side to the air side: Separator paper, Carbon powder with Manganese or Cobalt catalyst mixed in (and a binder of some sort, I suppose), a Nickel mesh (current collector) and a bit more Carbon+catalyst then a microporous Teflon(r) sheet (permeable to gases but not to liquids). I cant find nickel mesh where I live but the other stuff I could get--the Teflon(r) being replaceable with oil paper??? Any help would be greatly appreciated. N.B: I am Not trying to infringe on a patent, just trying to make some "homebrew" air electrodes for R&D; since I am still (steam comes out of ears) self-funded and low on Thanks a lot!!! =)

Question by gizander    |  last reply

Wondering what I can do with this hollow cathode tube...

I've got this hollow cathode tube from a spectra aa machine (used for metals analysis). It was supposedly still working - my old boss at the lab I worked at found it and considered tossing it out as they no longer had that AA machine (they had upgraded to an ICP/MS), but knows I collect interesting looking things. Am I right to assume that cathode tubes are quite dissimilar to the variety of tubes used in vintage amps and of no use in that regard? Does anyone know what sort of power I'd be looking for to even get this thing to light up? On the plug at the end of its cable, they posts are labeled A through F, then H, J, and K.

Topic by incredibleweirdo    |  last reply

Can someone help me with common cathode leds and push buttons?

Hello everyone! Im planning on doing a thingy like this for my son, can it work? Im going to use a 3V 1A power source to connect 3 push buttons to a common cathode led, like on the image included. I was planning to use this led: and switches like this:;=STRK%3AMEBIDX%3AIT is says: Light Voltage DC 3V In my mind it looks like this: if u push the red, the led will turn red, and u can add additional colors to it with the other 2 buttons. Could this work? If I figured it out good, I wont need a resistor for the blue and green, but I will need one for the red. How big it should be? Is it a good setup that I solder the positive to the switches and the black/negative to the one led? Can I add an another lead from the power supply to an another independent switch and single color led?

Topic by Smitiz    |  last reply

what would be the best way to hook up many blue liquid cathodes built in to furniture?

Hi again!Let's just say I took a hundred of blue liquid cathodes and went across the bottom of a sofa...These: was wondering what would be the best way to hook something like this up? I mean yea I could get computer power supplies, but is that really necessary? How safe would this be?Thank you all for any help you can give!

Question by lil devils x    |  last reply

CRT projects

Does anyone know of a good (and cheap) project I can do with a CRT (not a monitor, just the tube)?

Question by nikv95    |  last reply

Q's about Tubes ("JFETs with pilot lights")

Recently I acquired a couple vacuum tubes for $35, and I gave them about 7V filament voltage, and randomly probed around with a 50V 200mA HP lab power supply to see if I can get them to do anything. I found that the most I could get was 40mA between the heated cathode and the closest gate on the pentodes, and a few mA when connected "properly". I guess I just don't have a high enough voltage. :/ I don't want to mess too much with direct mains, and I don't have an isolation transformer. I have a bunch of different tube numbers, although they all look the same to me. (some of them have different inners though!) So my questions are: * Any cool project ideas? I'm thinking FM radio w/ bluetooth tube speaker thing (obviously w/ a separate module) Maybe a nixie display too??? IDK!  * What do I need to know to get started with messing with them? * How do I know if I am pushing them too hard or damaging them? I got the anodes glowing, and the current drops proportionally. Bad? * Most of them are labeled "radio tubes" some probably were in early TVs as well. * How much current/voltage do these things typically require? Can I do any sort of dark tricks to get them to operate well at or under 48V? I know some tubes were special and can run at 12V due to design.

Question by -max-    |  last reply

Cold Cathode lamp with SOLAR power / battery?

I have an cold cathode lamp from a scanner. I want to install it behind a piece of artwork i made to sort-of backlight the image. it can be very dim... i don't need to get full brightness out of it. My question is.. do you think this is possible with a solar panel and rechargeable pack of some sort to dimly light this thing???? I really want to use solar on this, due to the nature of the piece itself. Any ideas on watts or volts or any other input??? On the power input for the scanner itself it reads 16VDC 0.9~1.0A... if that helps. any help or suggestions are welcome!!! thanks !

Topic by fleanine    |  last reply

Would a 12" Cold Cathode light fit anywhere IN an Xbox 360?

I currently have already installed 4" cold cathodes but was wondering if 12" lights would fit.

Question by Steeps5    |  last reply

Will my Cold Cathode Computer Light work?

I just bought a Coolermaster ULTRA AURORA (DUAL) from a local store. On arriving home, i went to place it in my new HAF 932 case from Coolermaster. I have open slots and power supply for it but my video cards are to big to place it from the inside into the rear panel port. It has a on and off switch and a dimmer on it. Since i cant fit it in, i looked at bypassing the switch. the cord that plugs into the psu can fit in the switch or the inverter. I wanted to know if i can SAFELY bypass the switch. Go directly from the psu to the inverter to the bulbs is my plan. Would that be bad for anything? Coolermaster was of no help. Apparently, the model is 5 years discontinued no longer has manuals on file. They were less then helpful.

Question by trf    |  last reply

What part of a cathodic screen is of most value?

If you have a cathodic screen what part of the product is of most value (What part can be exchange for the biggest amount of money)?

Question    |  last reply

How do I make a power inverter for CCFL's? Answered

I want to know how to male a CCFL power inverter because i have a lcd screen backlight, but i never had the inverter for it. ho do i go about making one?

Question by zack247    |  last reply

Scanner inverter outputs

I've just been wondering about the output of scanner inverters for a few projects, what kind of voltages and amperages are they outputting. I have a few little ideas but don't really know that much about their outputs, I gave googling and parts numbers a go but mostly found unrelated pages or had no luck with part numbers...

Topic by killerjackalope    |  last reply

Laptop LCD Cold Cathode re-use

So recently, an old laptop of mine died. It was an old dinosaur of a laptop, slowly running down the remaining years of its life. Then it died. So sad. To honor its death I dismantled it. I got an interesting motherboard, some decent speakers, a 5gb harddrive along with a floppy and disk drive. What really interested me the most though is the LCD screen. At first I hoped that I could re-used the screen as a tertiary screen for my desktop, but later I realized the near-impossibility of this task and gave it up. Instead I chose to take the screen apart for its cold cathode lamp. It's almost 12 inches in length, and very thin. Before the motherboard died, the LCD back light was still working. So I wanted to take it out, along with its inverter, to attempt to re-use it. Soon after doing this I saw a problem in my plans: the input of the inverter is a whopping nine wires. This is a bit more than I'm used to dealing with for power supplies. I was wondering if you guys knew any way that I could go around this? At request I can most more pictures and model number of the inverter in case you can't read it in the photo. tl;dr - Cold cathode inverter in picture. output is two wires, input 9 wires. How do I use this

Topic by Pixel_Master  

Hydrogen Fuel Cell Porous anode and cathode?

I found this image that details a hydrogen fuel cell (reverse electrolysis). Does anyone know what materials are good for the porous anode and cathode? Is carbon porous on a molecular scale? I want to make a simple reverse electrolysis in order to use hydrogen power. I would appreciate any help. I got the image from here:

Question by mykiscool    |  last reply

$10,000 prize for Cathode Ray tube recycling

Innocentive is giving away a $10,000 prize to the entity who can show how to best recycle cathode ray tube glass. See details:;_medium=cb&utm;_campaign=9933317

Topic by flyingpuppy    |  last reply

Does Thermionic emission require vacuum? Answered

Will a hot cathode emit electrons outside of a vacuum? If that won't work, what other ways could I get electrons in a non-vacuum environment? The only thing I can think of is making some plasma and pulling the electrons out electrostaticaly.

Question by Jaycub    |  last reply

I broke an LED; will connecting the one wire leading in to the wire leading out break the device?

I have a broken LED. Will connecting the wire leading into the LED to the wire leading out of that one LED break the device? I don't have solder so my plan was to twist together the stripped wires and wrap in electrical tape. Would powering on the device cause any sparks? The LED is part of a group of LEDs in a ring around the cone of a hair dryer. There are wires leading up to this ring-shaped circuit board with six leads and a resistor. Would directly connecting the two wires leading up to this ring-shaped board break anything or potentially be hazardous if operating the hair dryer? Now that I think about it, the electrical tape would not be a good idea as it would probably melt pics:

Question by guyersky    |  last reply

common anode and common cathode differences in 7segment display

What are the changes need to do when using common anode seven segment display instead of common cathode seven segment display. hint:use transistors?

Question by nethmi.amanda.3344    |  last reply

In a vacuum tube, are the anode and the cathode connected in any way? Answered

In the wikipedia article, they refer to the cathode as a filament, which I thought was a bit odd. The only other filament I'm familiar with is in a light bulb. I was reading a book about vacuum tubes earlier, when I looked them up in wikipedia searching for a diagram: vacuum tube. Basically, a vacuum tube is a capacitor with a vacuum as the dielectric? Does a vacuum tube retain a charge? They seem to have the same principle: anode, cathode, dielectric. In a way, a battery seems to also be similar; the difference being the galvanic process involved. I attached a picture of a Daniel's cell from back in the day.

Question by Vorenus    |  last reply

LED, bipolar diffused common-cathode ultra wha?!

I was browsing through one of my local supplier's LED catalogue..Literally overwhelmed by the types of LED out there.. Diffused, non-diffused, super flux, super bright, ultra bright, common anode, common cathode, flashing, bipolar, etc..Anyone care to enlight this electronics noob? Plus some of the LED spec says something like 630nm, 1800mcd, what do they mean? Thanks..

Topic by gyromild    |  last reply

How can I make a power supply for cold cathode lights that would normally go into a computer power supply? Answered

I'm looking to put some cold cathode tubes behind my flat screen LCD tv and my computer LCD. I was going to pick up the Dioder lights at IKEA until I saw they were $50 for a set of 4!!! Any ideas? Is there an instructable that I missed? Thanks all.

Question by Joaquin9    |  last reply

My CTX PR960F CRT monitor is too bright and colors are washed out. How can I repair it?

Its a CTX PR960F 19 FD Trinitron (0.24 mm). I know its old, but its a very nice monitor and still in daily use. Someone told me once on a forum that "... a bright and washed out display as you describe it means resistor "so and so" has a very high value...." and then he dissapeared without explaining where it is or how to replace it. This was like.. 3 years ago. Any help, greatly appreciated!

Question by blakeredfield    |  last reply

How can you tell what is the anode and cathode on a tri-color LED--it has 4 leads? Answered

Its this LED here also what is the best way to hook it up

Question by Fresnel110    |  last reply

How, exactly, does a 5AR4 protect against cathode stripping?

I'm in the midst of designing pp 2A3 monoblocks with stand alone power supplys.  I'm thinking more and more about tube life with these triodes being a bit expensive.  Are there other rectifier tubes that will provide the same protection?  I was thinking 5Z3 rectifiers but not sure about potential stripping problems with these.  Can anyone help me out here?

Question by bogenfan    |  last reply

I have a question about electrolysis...

Why doesn't it work when I put the anode and the cathode in two different container when I am separating hydrogen and oxygen from water in electrolysis...?!

Question by nicki0850    |  last reply

is koolaid better for you than soda?

So the big koolaid (the drink) better for you than soda? or equal? BTW: i just ordered new blue cold cathodes and i fixed the gears on my old bike.

Topic by Yerboogieman    |  last reply

i would like to power a stip of led's or 1 Cold Cathode using a usb is there away to do that thanks in advance

Want to use a pc's usb to power a Cold Cathode light or led lights for a pc trolly that i am building

Question by udeth    |  last reply

cold cathode light totally interferes with my IR remote control!!!

I have a view-box for looking at negatives that uses cold cathode tubes as the light source--whenever this light is on my IR remote control for my wifi radio does not work--i have isolated it to EMI from the light not the light itself. when i covered the peripheral area where the wires and 2 ballasts are with 2 layers of heavy duty aluminum foil it drastically reduced the interference. i cant practically use the foil. Does anyone think ferrite snap cores from radio shack will work? if so-- where and how many should i put?--really need help--i have little electronic experience--

Question by roccosiffredi    |  last reply

Using Common Cathode Instead of Common Anode rgb led with IC?

So I'm trying to do this: and I realized that I have the wrong kind of led..the author says you have to "adjust the connections" but I don't really know how. Right now my led will glow but not change colors. Does anyone have experience with this?

Question by njaber    |  last reply

LEDs with short leads causing problems? Answered

So for Christmas i got a bunch of these leds from amazon and im making and led cube with them. the problem is the leads are so short i use copper wire to give some space for each LED. so for instance its    [Cathode]-----copper wire-----[Cathode]     . But as i solder one end of the copper to one cathode, it will melt the connection at the other end causing me to re-solder once it cools, sometimes it total luck that it stays.  So if you can understand this, does anyone have a more productive way to make this cube?  (and please dont say get LEDs with longer leads)

Question by texpert    |  last reply

ccfl inverter, samsung sic320?

Hello, my laptop recently died, i killed it, anyway, i have salved some stuff, one of which is the cold cathode and inverter assembly, except, i cant get it to light up, i tried everything, i hope i didnt kill it.  It is a samsung sic320 inverter board, if you hold it where the wires are facing up, from left to right in wire color is, orange, red, brown, and black, i dont have a camera, i killed it to expirementing, but just wanted to know which wires lit the cathode and at what voltage.

Question by cburgess7x    |  last reply

Is it true I need a 7448 chip if I'm using a common cathode 7 segment display?

At the moment, I have a 7447 decoder chip connected to a 7 segment display with two common ground connections on it. However, it's not working, and I read somewhere that you need a 7448 decoder chip to power a common cathode 7 segment display. Is that true?

Question by Ke-Bob    |  last reply

My front shocks

My front shocks are WAY too soft, i need help tightening them or making them harder, not including water. Thanks!

Topic by Yerboogieman    |  last reply

9 pin, 1/4" input/output. Which pins are the anode and cathode? [PIC]

I have an 9(?) pin 1/4 input/output. I got it off an old radio. Which of these 9 pins would be the anode and cathode? Looking at the pins, starting from the top there are 3 rows. the first row has 1 pin labeled (1). The second row, 4 pins labeled from left to right (8, 7, 4, 5), last row, 4 pins (9, 3, 2, 6) Any help would be amazing, as I am trying to ghetto rig a distortion pedal.

Question by surlistyc    |  last reply

What metal doesn't react with sodium? Answered

I am trying to make sodium. I used graphite and copper wire at the anodes and cathodes. Both of them combine with the sodium and corode. That leaves me with 0% sodium.

Question by chinarian    |  last reply

Any advice on testing/powering a CRT from a TV?

I recently salvaged a three color Cathode Ray Tube unit from a big screen TV  (unknown damage) and I've  never worked with them before. I don't know if there is a best way to test them out or what if any special gadgets I might need to do so. My goal is to re-purpose the unit as lighting for my Halloween display. I'm just interested if they can produce light and if I can control the brightness of the light.

Question by JaneSays    |  last reply

Circuitry for lighting

Hey all, I have never really done much circuitry to this date, but I was hoping to make a fairly complex lamp that may require a good dose of it. What I'm looking to do is wire four cold cathode tubes (12V, the kind that are used to light computers), as well as two LED lights with arduino based flicker control, and run them off of a wall socket? The pictures are a (very) rough sketch of the setup, as well as a supply list. Is there any way someone could explain what this might require to me in baby terms? All the best, Adrian

Topic by am_rawr    |  last reply

whats the best/cheapest way to drive 20 or 30 common cathode rgb leds with an arduino? Answered

I would like to drive 20 or 30 leds i got on ebay to put in my truck. i already got some code to change the color of the led with pwm using only one potentiometer, but i am not sure how to power the amount i need. it will need to use the 12 volts or so available in my truck.

Question by hivoltage    |  last reply

How can I create a manually controlled rgb led controller?

I have a 4 lead common cathode led.  Would it be as simple as building an led driver circuit and placing a potentiometer between supply and each anode?

Question by chandlerman    |  last reply

Does Chromesteel disolve during copper-electrlysis with Coppersulfate?

Hi I want to refine some copper and change it to copper-dust-particles by means of copper-electrolsis in a bath of disolved coppersulfate. Since my copper is in smaller bits id like to have some sort of etallic basket to hold the scraps. I think i would like to go with a chromesteel-mesh i connect to the power. The mesh/basket contains my scrap-copper and the anode-sludge can pass thru the basket... The basket (anode) and the copper-cathode are connected to the powersupply. Now my question: I think the chromesteel shouldnt get disolved as long as i dont crank up the voltage too high or let it run without sacrificial copper at the cathode. If i would do that, it would start to split the water used in the solution and produce H and O. Bad. Also would slowly eat away the metals too. Bad^2 But as long as i have copper to be disolved at the cathode, it shouldnt do anything to my chrome-steel-basket, right? Thanks for inputs from someone who knows it better than i do :)

Topic by Orngrimm    |  last reply

How do I get a 7-color LED to just blink continuously?

I'm working on a sculpture that involves LEDs.The basic instructions I've been using come from steps 2 and 3 from this tutorial - I'm attaching the leads of the LEDs directly to 3 volt lithium watch batteries. However, I decided to try to use a 7-color blinking LED, and I'm having troubles.The LED packaging says it has "single-color, color-changing or flashing modes." The LED has one anode and two cathodes. When I attach the anode and one of the cathodes, nothing happens, and when I use the other cathode, it cycles through all of the modes in about 30 seconds, and then turns off. The only way I can get it to start again is to take the leads off and start again, but this isn't an option for my project, being as the entire circuit has to be covered in glue to waterproof it.How do I get the LED to just blink continuously? Any help is greatly appreciated.

Question by hezzer    |  last reply

rgb led

Red green blue common cathode light emitting diodes anybody know any cool projects with them? The best ones I found were the hypno cubes and pov's, and some displays were cool. any others? I want to know before I buy a bunch of leds to save on shipping.

Topic by guyfrom7up    |  last reply