Introduction: Fluorescent to LED Conversion Under $30

Welcome to my first 'ible. I have done a lot of projects, but this is the first time I've documented one well enough to create an 'ible. The purpose of this was to create an LED lighting fixture that was as bright as a the original fluorescent, and even more economical on power. The side benefit would be getting rid of the need to climb a ladder to replace fragile mercury-filled tubes.

First off, if you are not comfortable working with real electricity, DON'T DO THIS.

Second, read the whole thing before starting work. Some steps are optional and if you actually do some planning, you can probably do this better. This was kind of a seat-of-the-pants proof-of-concept thing.

What I did was to remove all the fittings to hold the fluorescent bulbs and all the normal wiring from an overhead lighting fixture in my kitchen. I replaced them with a self-adhesive string of ultra bright LEDs and an old 12V power adapter from an old cable TV box.

Supposedly one 32 Watt fluorescent tube produces 2600 lumens, and there were two tubes in the fixture. The LED strip is supposed to produce a total of 2600 lumens, but my impression is that the LEDs were brighter than a pair of tubes. Perhaps my eyes adjusted, or the fluorescent tubes may not have been performing as they should. Since the fixture was defective when I started this project I find myself unable to do a comparison. I hope that someone else will be able to do a before and after test.


Step 1: Parts & Tools

The parts that I used included:

  • A dead fluorescent lighting fixture ($0)
  • A 16.4 foot high density roll of 600 LEDs - 5000K, 164 Lumens per foot ($23)
  • A spare 12v power adapter I had laying around ($0)
  • Salvaged wiring from an old computer power supply for jumpers ($0)
  • A zip tie ($.02)
  • A bag of veggie strings as snack food, since I was figuring this out as I went along ($4)

The tools that I used were as follows:

  • Wire strippers
  • Slip-joint pliers
  • Screwdriver
  • Scissors
  • Clamping tweezers
  • Angle cutters
  • Needlenose pliers
  • Soldering iron & solder

You may need other tools depending on the model of lighting fixture that you are working on. Other fixtures around my house would have required nut drivers in order to access some of the nuts. On the kitchen one I was able to use slip-joint pliers for all the nuts.

Step 2: Disassembly

This is another point where I will say that if you aren't comfortable with real electricity (AC in the wall) then don't do this. Also, if you are not mechanically inclined enough to strip out the ballast resistor and other wiring from the fixture on your own, you probably shouldn't be doing this yourself. Before you complain that I'm leaving stuff out, I have looked at the three fixtures in my house and they are all quite different. I'm confident that the instructions to disassemble my lighting fixture would bear only passing resemblance to what needs done to clean your fixture of its old guts. I ended up only needing a screwdriver and some slip-joint pliers.

Step number 1 is to find the circuit breaker that controls the thing you're going to work on. Since I was working in the kitchen, I got the unfortunate news that the light above the stove and the one over the sink were all on the same circuit. It crossed my mind that I could possibly work on the lamp wiring by relying only on the light switch for the lamp so that I could still have a couple lights to work by. Then I realized how stupid that would be and left the circuit breaker off while I worked. If you're wondering why I had to use flash... there you go.

Once you have removed everything down to the frame of the fixture, go through the wiring and see if it is suitable for use for jumpers. If so, hang onto it. If not, then you will need another source of wire. I used a bunch of wire that I took out of an old computer power supply.

Step 3: Install LEDs

The string has an adhesive backing. The peel off backing was buckled because the strip is shipped on a spool. It took some work to get the string stuck down well. If I do this again, I will probably add something as insurance to make it stick better.

You don't have to cut the string apart, but I did in order to avoid curving the string. Play with how you want to line them up and see if the bend radius is acceptable. I wanted all the LEDs aimed down because of the way the fixture was designed and I thought the soldering would be pretty trivial for me. If soldering is a weak spot, then you don't need to cut the strip. Just stick it in place and call it good. It was a 4 foot fixture, and I had a 16.4 foot long string of lights so I ended up with a few inches left over after I got them all put in.

The important part is making sure that the power connector is in a good position to reach the power supply.

Step 4: Solder the Jumpers If Necessary

If you cut the string apart, then you will need to make jumpers. Measure the distance you need and use the wire cutters or the cutting surface on the strippers to cut your jumpers. Strip them back about 1/8". Another reason I used the computer wiring was so that I could be careful about the polarity. + is red and - is black. This is important because the way I arranged the light string, I ended up with the polarity reversed across each jumper bridge. That's what happens when you're making it up as you go along.

Put a drop of solder on the ends of the jumpers. This is called "tinning" the leads. I use the clamping tweezers for holding the jumper while I tin it. It normally takes a little while for the flux to get the solder to wick into the strands of the wire. Make sure the soldering iron is hot enough and work quickly. The first jumper I tried to tin was done with an iron that was too cold. I went ahead and held it in place long enough to make the solder flow, and the heat soaked down the wire and melted the insulation. If you do the same thing on the string of lights, you can burn the nearest LED, or melt the solder that holds it in place. Work with a hotter iron and move fast for good technique. Do all of the jumpers before you start tinning the light strip to get "into the zone".

Then tin the copper jumper points. Put a drop of solder on the copper and get a nice shiny little dome.

Having solder on these two parts separately will make it so that you can join them together quite easily. Since you are soldering close to surface mounted components, you don't want to spend too much time soldering and overheat anything.

Then hold the jumper against the solder point (verify polarity!!!!!) and hold the iron against it just long enough to melt the two together. As soon as the solder melts, take the iron off the puddle and hold the jumper in place while it cools. I used the needle-nose pliers to hold the jumper without risk of burning my fingers.

Step 5: 12V Connection

Since the fixture hangs from the ceiling and the top is reasonably well concealed, I decided to just throw a zip tie around the power brick and secure it that way. I ran the 12v connector down a hole in the fixture and plugged it together.

This is the time to test all your soldering. Plug the power brick into a working outlet. I had one in the living room that was controlled by a switch, so I plugged it in there and threw the switch. Everything lit up nicely and there was no sparks.

So far so good.

Oh, and it's BRIGHT!!!

Step 6: 110v Power Connection

The hanging wires were secured to the old fixture wiring with twist caps. If your fixture plugs directly into an outlet in the ceiling then you won't need to cut off the plug. Just use the plug if you can. In this case I had to cut off the plug and strip the wires back the correct amount for the particular twist cap in use. The dangling wires were stripped back 3/4" so that's what I did to the cord for the power brick.

The connector that I cut off the power brick was not polarized, so I didn't worry about polarity at all. I just connected the ceiling wires to the wires of the power brick with the same twist caps that were used for the original fixture.

Once I was confident everything was connected properly, I turned the light switch on and went out to enable the circuit breaker. I watched through the kitchen window for a minute to see that nothing sparked or caught fire. It would have been much faster to get the circuit breaker back off if anything had gone wrong. Nothing did, so I closed the panel on the circuit breakers and went back inside.



bobchabot (author)2015-11-10

I did this conversion in the nasty light box in my kitchen. Worked great but to be honest the amount of light from the led strips half the fluorescent put out. It's ok. I'm satisfied I did it. My ugly kitchen box needs to come down eventually. I'll move the led strips to the closet or shop table light after. Great inspiration!

bobwojo (author)2015-02-22

I just purchased two 4" LED shop lights from Sams Club for $35 each

5000K, 4200 lumens. Sell the old fixtures and buy new!

ChrisP14 (author)bobwojo2015-08-20

Finally spotted this myself. Don't need to change out tubes now that these are on the market. I'll be replacing the one in my shed instead of rewiring. Any problems, I'll post here. The ones at Costco are 3700 lumens, so I suspect a different manufacturer.

mikeyc.2009 (author)bobwojo2015-02-22

Do you know if they are dimmable?

bobwojo (author)mikeyc.20092015-02-22

The manual says no.

Lights of America #8140SE-WH5, Not on their web page, probably made exclusively for Sams.

killroytech made it! (author)2015-07-30

Converted a desk lamp, and a small tube neon ceiling lamp. Had to change the switch, no big deal.

Used a 12v power supply, with 1.5 times the amps required by the LEDs.

Also,I put a strip of "glow in the dark" masking tape inside the ceiling lamp. If the power is out suddenly, it's bright enough to serve as an emergency light!

ConvNeonToLEDs_04.JPGConvNeonToLEDs_07.JPGLampe conversion_3.JPGLedLampe1_3.JPG
KROKKENOSTER (author)2015-03-14

Hi! A friend of mine was able to get me lamps for about $3.00 and I replaced the NEW fluorescent lamp with just two of the LED bulbs that gave me a brighter light than the dual fluorescent fitting eating 80 watts while the LED only consumed only 7 watts each.They look just like frosted incandescent lights. I opened the one to see the PSU and the real voltage of the led's and I found that there is thirty five of then in series and the PSU is just a series capacitor full wave rectifier and smoothing electrolytic. (We use 240 volts as mains). I then replaced all my lamps with these lamps. The (LONG LIFE) CFL's only lasted between 9 to 24 months and they are only half the price of the LED lamps.I had on one circuit a CFL and an incandescent lamp and the CFL had an average life of nine months and the older incandescent still working after 25 years!! If you want to claim on the warranty of 24 months they have a whole library of reasons why it is your fault that they fail!!.Fantastic idea and now to find a source here where I stay................................??

walter.warren1 (author)2015-02-12

Fluorescent tubes dim over their lifespan, so the 2600 lumen figure you found is probably "initial lumens." Depending on their age, they may have dimmed considerably.

I'd been considering replacing some fluorescent cove lighting that reflects off a ceiling as the room's primary light source, but hadn't considered trying the tape LEDs. The LED tubes are still very expensive. I appreciate knowing from someone's actual experience that a reel of tape is comparable to two tubes.


The vendors always say "20,000 hours" or some made up number, but that is dependent on heat. Cool those chips well, and they'll last longer than you will. I see a lot of flashlights and toys that overcurrent the LEDs with no decent heat sinks, and they dim fast.

ac-dc (author)walter.warren12015-02-15

LEDs also dim over their lifespan but the lifespan rating for fluorescent takes this into account, that they don't just fail at that point, rather dropping below a % of rated output.

Odds are that if they were used for several hours at a time, the T8 fluorescent tubes would outlive the LEDs. LEDs "can" have equal or better lifespan but only if kept at a lower, cooler, drive current.

joe.andolina made it! (author)2015-03-04

I have been having trouble with the fluorescents in my garage for some time. After seeing this ible I knew it was for me.

Thank you.

ChrisP14 (author)joe.andolina2015-03-07

Outstanding!!!!! Is that a properly functioning fluorescent right next to it? If so, that's a really important picture. Clean work, and thanks for posting!

CoreyCoop (author)2015-02-16

I have found two strips of the 5000K LED strips ("Bright White") matched with one 3000K ("Warm White") makes for a better tone, not as taxing on the eyes, but still bright and good for detail.

bhirsh (author)2015-02-16

Nice job at re-purposing an old fixture. AS far as the techy side goes, RELAX! It lights and it works for him. That is what is important. If somebody wants to study LED's and come up with a better light, please do it an post so others can learn. In the mean time, this works, good job! IF I was going to mass produce and sell these, then I'd study all about LED's and power supplies and glue, and.......

ve1fsm (author)2015-02-16

Great idea, I used some of the self adhesive lights under the counter and use a 12 block . If I do one of these lights I think I would mount a electrical box on top and plug the Box in, My wife would love a extra place to plug in Christmas lights without running cords.

jimvandamme (author)2015-02-16

Seems like LEDs on reels come in either too blue (5000K) or too yellow (2500K). Both look terrible to me. If or when I find some that are neutral white (3500K) I'm going crazy with relamping the house. I've gotten big 10W chips that are just right, but no strip lights.

schmitta (author)2015-02-15

The balast is not a resistor. It is an inductor

LaserDave (author)schmitta2015-02-16

Actually, that ballast is a transformer. The magnetic device in the older-style lamps, that required a starter, would be classified as an inductor.

LaserDave (author)schmitta2015-02-16

Actually, that ballast is a transformer. The magnetic device in the older-style lamps, that required a starter, would be classified as an inductor.

gregjd5000 (author)2015-02-16

Great 'ible! Someone already mentioned deep in an essay below but it's a good note. Wire all of the strings in parallel (like an E shape) instead of in series (like an S shape). This will insure all strips get the same voltage so they all light up the same beightness

Hugu (author)2015-02-14

with less than 6€ you just can buy a led tube lamp and change the fluorescent lamp!.. more cheap and easy!!

rusty0101 (author)Hugu2015-02-16

If you can do this, I'd say go for it, with the caveats that there are potential safety issues that some of the fluorescent tube replacement led bulbs have.

First up, make sure that the bulbs are certified for your location and use. Whether that's CE or UL listings, check.

Also these tubes light in one direction. You may find that the light is dimmer than expected, in which case you may simply need to turn the bulb over so that the surface that was towards the reflector of the fixture is now away from the reflector.

That said, having the bulb face the reflector may give you more indirect lighting that might be better for specific purposes, like having them set up in a reading room.

There is a video from eevblog laying out some of the issues that have been found with some of the various led tube replacements for florescent, (with the caveat that not all are being described) at It's eevblog #362.

onemoroni1 (author)2015-02-15

I like this, it makes changing the tubes obsolete, and I think more economical.

lqlarry (author)2015-02-15

The company I work for sells Carl Jr's a kit already made up for their menu board. A lot less fuss but doing it your way saves you BIG bucks. If you buy your tape online check and see if they have crimp on jumpers. These come in handy for people not comfortable or intimidated by soldering.

Also remember you can buy 2 watt or 4 watt a foot led and different kelvin temperatures, 3000k (= halogen), 4000k (= cool white fluorescent) and 5000k (= daylight fluorescent). There is some 6500k but it sometimes looks too blue.

Ted de Castro (author)2015-02-15

Do the math - I did -- LED's are NOT the most efficient. I looked up lumens and wattage of as many lights as I had on hand and/or could find in my hardware store and made a spreadsheet. The winner - 8 ft fluorescent - second 150 watt CFL. LEDs were good - but down a ways. There are many good reasons to go LED - I am trying to replace all my tube fluorescents after one broke in my face while changing it - unpleasant. I don't worry about the Hg - not enough to be concerned about. Just a point of information. Great Instructable - as soon as I find a spool of the LEDs I am going to try it.

starphire (author)Ted de Castro2015-02-15

If only it were that easy to come to that conclusion. Sorry to say, but your math is incomplete.

First, "lumens" is a raw measure of the total amount of light coming out of just the bulb. NOT the fixture after the bulb is installed. A percentage of rated lumens coming out of fluorescent tubes is lost forever because it radiates equally in all directions. Reflectors can recover some of that, but never all of it (and designers tried their best for 60 years to minimize it, including going to smaller tubes ). A measure of actual useful light exiting a fixture is called "efficacy", and LED efficacy wins over fluorescents - especially for more directional types of lights, such as spotlights. The numbers on the bulb box miss this important factor. So efficacy/Watt is a fairer measure, but comparing them is not trivial at that point.

Second, what you can find in your hardware store is NOT a fair assessment of what can be obtained in the lighting market. Just for perspective, LEDs producing over 300 lumens/Watt have already been demonstrated in the lab. That is starting to approach the maximum possible conversion efficiency, and better than twice what any other kind of artificial light has ever achieved in history. It will be years before LEDs in the corner store will be that good, but that is where the technology is heading. Fluorescents on the other hand maxed out their room for improvement years ago. But LEDs producing 150 lumens/Watt are in mass production today, most of which are going into things like streetlights and high bay industrial lighting at this point, not LED light bulbs for homes. No fluorescent bulb can achieve this, and that's before efficacy is taken into account.

Meanwhile, most everything going into retail stores is skewed toward LED bulbs that consumers will consider paying for because they don't do the math and aren't used to paying up front for energy savings later. These bulbs don't use the best LEDs available, but what is cheap enough in mass production today - maybe 90-110 lumens/Watt. Marginally "equal or better" than CFLs and good enough for Energy Star - therefore "good enough" for companies long accustomed to selling bulbs by the razor blade method. They aren't that interested in making the best possible LED bulb, just something consumers will buy. LED bulbs are also skewed towards "warmer" colors, which are less efficient but preferred by consumers.

Ted de Castro (author)starphire2015-02-15

Yes - of course! LUX would be a better unit to have but - lumens is what we have and LUX we would have to measure - when specing the output of a light source you don't know what fixture it will go into - therefore that can't be included.

In some applications - like flashlights - the forward angle of a LED is a great asset - for most commonly used room lighting - a liability.

Just saying that on todays consumer market - LED is not necessarily the most efficient choice. It certainly does have other advantages - and I just ordered my LED strings and at 1/3 the price in the instructable - 1/2 WITH the power supply (I'm sure I'm not allowed to say where here)! Elsewhere it was double the article price. SO search around (starting with the letter "A")

ac-dc (author)Ted de Castro2015-02-15

Current generation, state of the art Cree LEDs are more efficient - when paired with an efficient switching PSU. However, the cost of a product using them would be much much higher than a product using the generic Chinese LEDs.

Further, even using the generic LEDs if you simply drive them at a lower current and use more of them, then they become more efficient as well as longer lasting, but again the price rises so for practical purposes it could be impossible to recover the cost from a lower electric bill over a 4' or 8' T8 tube fluorescent.

aquascapist (author)2015-02-12

Nice work. Any idea how many amps your 12v adapter is?

ChrisP14 (author)aquascapist2015-02-12


When I was testing the strip with my Kill-A-Watt, it was pulling 22 Watts, so plenty of power to spare. The documentation that comes with the LED strip will tell you the power requirements for the particular unit you buy. Make sure to use the right one for your implementation.

ac-dc (author)ChrisP142015-02-15

If that is true then your light isn't producing remotely close to as much light as a single 32W fluorescent, let alone two of them.

They are a bit under 100 lumens /watt. 22W at wall then say optimistically 90% efficient PSU so 19.8W to LEDs. Now you may have at least another 10% or more loss from the current limiting resistor but let's say only 10% which reduces it to 17.8W.

Now let's say the LEDs are as high as 80 lumens per watt which I doubt, but let's still use an optimistic # for them ignoring how hot their dies are getting and then 80lm/w * 17.8W = 1424 lumens. That means the twin 32W fluor. tubes were 3.7 times as bright and were more efficient than the LEDs so long as you are using a modern (switching boost) ballast instead of the old linear transformer type ballast.

This is the dirty little secret that manufacturers using generic LEDs often pull over on consumers. They make claims of what an ideal LED at an ideal temperature and max current would produce in lumens, instead of what they are actually producing in a product as designed and used typically.

discostu956 (author)2015-02-12

are all the led's in series on the tape? Just wondering how 12v manages to power them all. you don't have to control current to these led's?

cfreitag sr. (author)discostu9562015-02-13

MRo47 is incorrect.
Those LEDs are wired 3 in series With a resistor to control current draw. LEDs (white) operate at 2.8 to 3.7 max and the upper voltage requires heatsinking to prevent diode and phosphor degradation.
That's why these 12v LED strips have a finite lifespan, especially when powered off low quality/regulated power supplies. They are over driven AND have inadequate cooling @ 12v.

ChrisP14 (author)cfreitag sr.2015-02-13

It sounds like the LEDs will die 3 at a time, but one dead LED won't take out the whole strip. Let me see if I understand.

So when one LED burns out, the other two in the same series will suddenly be getting 6v each? That will soon kill one of the survivors, and the other will die immediately after at the hands of a full 12v.

ac-dc (author)ChrisP142015-02-15

When one LED burns out it will break the circuit for that series of three so the other two LEDs stop getting power - while still capable of producing light.

You could solder in a replacement LED or measure the voltage at that point in the circuit and substitute an appropriate value resistor to result in the right current for that series. The LED is the ideal fix but to get a few delivered could cost several dollars while resistors are a penny or two a piece, can be had for $2 or less on an auction site or maybe on Amazon too, or Radio Shack in the US, or other electronics supply houses.

cfreitag sr. (author)ChrisP142015-02-14

Not exactly, if one led in a segment (3 LEDs per) the other 2 in that segment will not function due to open circuit caused by failed LED.
The rest of the LEDs on the strip will function normally. Those LED strips are made of small segments, usually 3 LEDs per segment, each designed to run independently on 12v.

discostu956 (author)cfreitag sr.2015-02-13

Thanks guys. Ever have thermal runaway issues with the strings running in parallel?

cfreitag sr. (author)discostu9562015-02-14

These 12v strips have a resistor to prevent thermal runaway issues by limiting current.

MRo47 (author)discostu9562015-02-13

Strip has 3 LED's connected in series then all 3 connected in parallel with another group of three LED's thus it requires 12v is 4 v/led. enough current is provided by the power supply

joseph.strubhar (author)2015-02-15

The LED strip lighting I've seen usually comes with it's own power supply that is made for it, and includes a dimmer function. I'm going to have try this with the troffered fixtures in my kitchen!

ac-dc (author)joseph.strubhar2015-02-15

You are better off sourcing your own PSU separately. The junk they include is not likely to last nearly as long as the LED strips themselves. "They" is referring vaguely to these strips and PSU pictured on Amazon. I do not own this specific set from this specific seller.

For longest life you are better off with a major brand 12V laptop adapter spec'd for only half the current needed, or you could modify one with solid polymer capacitors and vent holes to reduce operating temperature.

mikeyc.2009 (author)2015-02-15

Good job. I did something like this but with discrete LEDs. A lot of soldering.

I also able to change the switch to a dimmer because I used a transformer that was meant for outdoor landscape lighting. Just make sure that the dimmer you use is compatible with the power supply installed.

ElectroFrank (author)2015-02-15

Things to consider in advance: LED Colour - Cool White or Warm White ?
For most people (i.e. at home), warm white LEDs will give a much more comfortable ambience.
Cool white may be preferred for situations where colours need to be assessed in relation to daylight, e.g. looking at pictures and artwork.

This is also an opportunity to fit a dedicated LED power supply with brightness control, providing mood lighting and further power economy,
Using the LEDs dimmed will also increase their lifespan.

As mentioned by others, a DIY fitting gives a an opportunity to combine strips of both warm and cool white LEDs, and adjust the light colour by modifying the relative brighness of the two types. This would only require fitting two separate brightness controllers.

Soldering: This might be easier if you do it before sticking down the ends of the LED strip, because heat will be conducted away faster into the metal casing when in contact with it.

Current rating of power supply: (unless otherwise specified)
Individual LED current (about) 20mA
600 LEDs in series strings of 3 = 200 strings
Total current: 200 x 20mA = 4 Amps

So if your power supply is rated less than 4A, you will be overloading it. However, there may be a degree of "self-regulation", because if the power supply is overloaded , it's output voltage will drop, and LEDs take much less current when their supply voltage is only slightly reduced.

tlwbuilder (author)2015-02-15

I just converted a 4 bulb T12 fixture for $125 using commercial led replacements. I hadn't thought of this. Good job.

mark_sprague (author)2015-02-15

Nice instructable...if you did not want to do the soldering, there are connectors available on Amazon ( I have used these before and they are very easy to connect.

MGraves206 (author)2015-02-15

I bought mine from Amazon and it came with the connecting cables to do just this and a power adapter and this is not really hard...and buy a female power adapter and you don't have to cut the power supply cable you adapt the incoming power and now if the PS dies you just replace the bad part. BTW the Mother-in-law LOVES IT!

michael.oxman.1 (author)2015-02-14

Great job! I've actually wondered about retrofitting LED lighting and now I can see it can be done. Thanks for the solder tips.

richms (author)2015-02-13

If you power it from one end, there is signifigtant voltage drop along the strip that will make one end brighter than the other.

I would have put a positive and negative on each strip and then paralleled them all up into the power brick rather than looping like that.

silvertinkerer (author)2015-02-13

I want to do this for a friend in their workshop. I will show your instructable to them, see what they say.

cfreitag sr. (author)2015-02-13

Very nice 1st 'able.

Couple of things.....
1st, just so you're aware, those LEDs will dim and become cooler in color over time. They are not properly regulated or cooled (design flaw, not craftsmanship).
2nd, you'll find in the future using a mix of about 1/3 cool white and 2/3 warm white LEDs make for a much more pleasing and color correct light.
LEDs (white) actually use a blue LED die with a phosphorus coating to convert it to white. This phosphor can burn/darken over time causing dimmed and off color light. As well as the inherent color rendering issues when looking at food stuffs (Apple's, meat, greens, etc. Can look "off" under LED lighting)
Therefore a mix of phosphor is used to make high CRI LEDs..... OR you can use a mix of LEDs to get the quality you want.
I also suggest you keep power supplies like that one, external mounted, for cooling.
There are affordable proper LED PSs available with proper cooling on eBay and Amazon.
Also look into 5050 LED strips, these employ 3 LEDs per chipset and allow for fun flexibility in dimming and color control.