How to use burnt Compact Florescent Light Circuit Module

Note and precautions: CFL's contain mercury which is hazardous material, so it should be handled accordingly
Most CFL lamps, electronic circuits are working perfect and are still useable, only the bulb goes defective. CFL circuit of 18-24 Watts are useful for the activation ofreplacement type two feet 18-20 Watt Florescent Tube Light bulb.
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Step 1: Find a CFL

You will need a CFL as shown in picture. Any CFL of which bulb is defective, broken or has outlive its life is useful for this modification. Drive voltage may be according to your country 110 Volt or 220 Volts. In my country (Pakistan) voltage standard is 220/230 Volts.

Step 2: Disassemble

Disassemble the CFL as shown in the picture. Note there is a single pair of wires/connections which goes to the 110/220 Volts. other side has two pair of wires 9four wires) these will be connected to the replacement type 20 Watt 24" Florescent Light bulb. After disassembling you will need electronic module from it. Check carefully there are no burnt parts on it. Using multimeter check its diodes, fuse etc. some time fuse is found melted you can replace it or bridge with a very thin copper wire.


Step 3: Parts required

You will need a replacement type Florescent Light bulb of 18 or 20 Watts type and hardware to hold the tube bulb and ofcourse salvaged electronic module from the CFL.

Step 4: CFL module wiring

Rewire appropriate length of wires as shown, say about 4 to 6 inches.

Step 5: Mounting and Assembling

mount the parts and assemble. Note the CFL module shold be mounted on an insulated plate. I used a piece of Plexiglas and fixed the CFL module with a hot glue on it. For extending connections, use terminal blocks.

Step 6: Connect to light up

Now after assembling check all connections taking care there should be no loose connection. Now power up!!!. I have assembled three such units successfully.
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Don't get me wrong, I'm glad to see the electronics being recycled. What is the voltage that drives the various CFL tubes? It would appear to me that many of the power supplies provide 400VDC to the tubes. Is this correct? Do any of them provide higher voltages?
The Sky Pirate
Think of all the CFL bulbs going into landfills and the Mercury from those bulbs going into the drinking water and the worlds oceans.
The Sky Pirate
uadil11 months ago
Awesome Job :)
patrickvaz1 year ago
Hi, this is was a great info. thanks for everything.
Just a query, I have a CFL lamp, it needs a electronic ballast, works with 2 pins only as seen in the pic, can you suggest what needs to be done. cheers
iffee (author)  patrickvaz1 year ago
@patrickvaz. Your question is not clear to me.
patrickvaz iffee11 months ago
I have a CFL with 2 pins(26 watts GE) it need a electronic ballast operating at 230v ac, i have attached picture of the CFL, thanks for the interest. regards
kishore1 year ago
It was good recycling of CFL Circuit detaily explained project .I would like to ask you as I got circuit from old burnt out 8W CFL Blub .can I use for 18W Florescent light. will it work or I had replace some components on circuit, and does this circuit from CFL save electric consumption do reply....
iffee (author)  kishore1 year ago

I have not tried but guess,
It may not work or may work with dimmed light.
kishore iffee1 year ago
Thank you for your reply..What wattage CFL blub circuit you have used for this explained project.
iffee (author)  kishore1 year ago
18 to 25 Watt CFL will drive 18 to 40 Watt tube lights.
40 watt tube light was a bit dimmed. If you are from India then you may visit some "Kabaria" to get CFL modules. Good Luck
ant0ny1 year ago
Very simple and very great idea! Thanks! :)
Good one and I always got confused of tube wirings unecessarily......
kemog5 years ago
Hello, this is understandable and easy to accomplish. And I am interested for same thing but in car usage (12 V). do you have any ideas or instructions about using good parts of CFL with smaller fluo tube which can fit in rear part (trunk) of a car. Thank you!
iffee (author)  kemog2 years ago
I have circuit from

12V Fluro inverter

I built it and using since last 3 years, It is very efficient if built according to
the instructions,
wolfy_90055 years ago
Nice. Would it be possible to remove the but you attack to the wall and make a handle so you can use it like a portable shop light?
iffee (author)  wolfy_90055 years ago
It requires connection to the wall plug, so may not be convenient to use as shop light.
joinaqd iffee5 years ago
nice instructable,by the way im from Bangladesh..salam
iffee (author)  joinaqd2 years ago
Brother Wa-Alekum Asslam
msw1005 years ago
Great instructable You show a picture of a philips bulb with straight elements but the circuit is from the spiral CFL do you have the pinouts for the straight element bulb?
The straight flouro tube has two pins at each end. There is a low-wattage incandescent coil between the two pins at each end; just connect the two pins from one end to the wires that are next to each other on the electronics board, and the same for the other end of the tube - you should have four wires on the board which were originally connected to the spiral tube. Try to imagine the spiral tube "unwound" into a straight tube and you'll see how it works.
iffee (author)  MairseyDotes2 years ago
@MairseyDotes. Well explained
pako2 years ago
It's a good idea, I have a lot of dead cfl circuit and standby
using them as sources of high voltage, now installing it on old
lamps with ballast heavy and noisy, so
noise disappears and the ignition will be faster.
sun_ray20502 years ago
but with 40W FL
soon will try with twice electronic ballast
adi19772 years ago
Hello Sir

Its a great project. Please let me know can we connect 20X1watt led or 8x3watt led connected in series with a 20 watt cfl module. What changes have to be made.
iffee (author)  adi19772 years ago
This is not suitable for LED type lights.
chub24 years ago
Most common CFL are 18W to 26 W. if one wants to run a 40 w tube how do we modify the circuit?


labatt chub24 years ago
 chub2 you don't have to modify the circuit for  a 26W to 40W tube, the main concept is add some heat sink around the transistors or ground the tube  mettalic housing to. However all in all just try and implement the procedure in this instructable and you may be surprised that it works, For tubes they only fail to work because it fails to strike on, putting your hands  near the tube makes it strike (grounding)
chub2 labatt3 years ago
Thanks for your prompt suggestion, I have around 6 dead CFL lying around at home, I have tried your method, it works ! except for one which had burnt parts.

However, it is found that, CFL choke connected to the light light is not as bright as the original CFL.

arzhou4 years ago
Hi, I was wondering is it possible to buy the ballast commercially? I checked online but it did not seem possible. How much would a ballast cost?
iffee (author)  arzhou4 years ago

Main purpose of this instructable is to use those CFLs of which bulb has been burnt or damaged and its circuit (module) is in working order. It is a salvaged part and not sold separately.

For more information "About failed CFLs

go to your local hardware store 
 they are $25-$30
bronz4 years ago
Hello Sir
                 Looking at CLF circuit there are four pins ,two of which go to one side of the tube and the other two to the other side.Just a Curiosity ,how do we know which ones are +ve and which ones -ve.
                 And one more thing,the circuit intake is AC and output ?.If output is also AC.How can we make it DC.
sir,did you use the starter?
bronz4 years ago
sir this is excellent work. how much watt and current do you think will be suppling to tube1 and 2. And can we use the similar process to make an adopter. Thanks
iffee (author)  bronz4 years ago
@Bronz: There is only one tube 20 Watts.
12V4 years ago
some times i have cfls sent to me for free.
iffee (author) 5 years ago
@alcpower1 1. Your CFL module should compare by wattage to the lamp you want to use. little can be tolerated, say for 8W you can use 6 to 10 watt type CFL module. 2. No starter required. 3. There are 4 wires to be connected to the tube (2 each side) If the CFL module and Tube are perfect then seems no problem..
alcpower1 iffee5 years ago
Dear iffee, I did exactly as you suggested. I obtained a 9 watt CFL module (to match closely to my 8w, 12" fluorescent bulb) and it worked the first time. It is very bright, no flickering, and I saved at least $14 from having to purchase a new ballast for this set-up (3 gallon fish tank hood light). Thank you for your Instructables. Best Regards, AL Santa Clara California
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