Make a CLL (Compact LED Lamp) From a Dead CFL(Compact Fluorescent Lamp)




Compact Fluorescent Lamp(CFL) is becoming popular day by day because of its ease of instillation and low power requirements.They have a fairly good life of about 2 to 2.5 years depending on use. I was having 4 dead CFLs and was wondering how I can recycle them. I got an idea to make Compact LED Lamp (CLL) from them. Read out my instructable to get to know how to make a CLL from dead CFL. Its easy, economic & fast. It took less than hour for me to make a CLL. So lets start.....

Step 1: What We Need ?

We need the following material to make a CLL
1) Dead CFL(s)
2) Bright White LEDs having such size so that they can fit into the bore of tube of CFL.
3)Solder & Soldering Gun
4) A power supply (discussed in detail in notes).
5) Screwdriver, hammer, hacksaw, adhesive, adhesive tape, etc.

Step 2: Lets Get to the Work

Now, first of all we need to open the dead CFL and remove the ballast circuit in it. First remove the end connecting cap by screwdriver as shown in photos and disconnect wires. Then try to open the upper portion of the plastic assembly that holds the glass tube. It is anchored in the base plastic assembly that holds the ballast circuit. For some CFLs these two may be sealed with adhesive. Try to open them by screwdriver so that anchoring releases or simply use hacksaw to separate then as I used, Be careful while using hacksaw, cut it in circular fashion not from top to down. When you complete separate 3 parts of CFL, cut down wires connected to glass tube and remove ballast(choke) circuit from the middle part.

Step 3: Breaking the Opening of Glass Tube

This part is very important and risky too. If you got a CFL of 11 W (As I used here), it contains main two tubes. No of tubes may be more for more CFL having more wattage. But there will be only 2 electrodes. We need to take these electrodes out. Using a wire stripper break the uphaving glass part of electrode. It may fall down in the tube. Make tube vertical so that it comes down again. Using screwdriver or any tool u find suitable make small pieces of electrode by breaking it in the tube so it comes out totally. No part of electrode, especially metal wire should remain in the tube. Don't strike screwdriver on inner walls of the tube as it will remove the inner fluorescent coating. Once you remove both the electrodes, you get two openings to tube. Broaden them carefully so that your LED can enter it.

Now for remaining you need to be careful. For CFL used here, there are two totally sealed bottoms of tube that we need to break. Use a sharp nail or screwdriver and gently break it by hammer. Be gentle, this could break the whole tube. So finally, you should have opening for every section of tube from bottom.

Step 4: Arrange the LEDs

Now the part comes to arrange LEDs. Connect your soldering gun to AC supply and get ready. You can choose any no of LEDs depending on the length of dead CFL you are using and your light requirements. I have used total 24 LEDs here as 6 LEDs in each tube bore. You can either use series of parallel connection. Parallel connection would require huge reisistance to connect with it. Also it may not fit in the tube bore. So I prefer series connection.

As illustrated in photos, get rough idea of how much should be space between two LEDs. I have kept space of about 1 cm between two. Then cut extra leads and go on soldering. Make bunch of 6 LEDs (or any no you want) in total 4 (equal to total number of tube bores). You need to connect a wire to lead of LED that goes innermost in the bore to connect it further.Insert every bunch in tube bore very carefully. Make the connection of all LEDs so that they are as per shown in circuit diagram. Finally you should have all the LED bunches in the bore of tube and only two connecting wires coming out.

Step 5: The Power Supply

Hmm.......the tricky part now comes. You can run LEDs directly on AC supply as they itself rectify the AC, however this is risky and reduces life of LED.I have used a bridge rectifier to improve life. You must connect appropriate series resistance. To calculate series resinstance-
I have 24 LEDs in series.
Max voltage drop in each LED = 3V & current is about 20mA ( for LEDs I used, this may differ, refer datasheet of provider or estimate by multimeter)
for 24 LEDs 3*24= 72V
AC supply available at me = 230V
Voltage to be dropped in resistance= 230-74=156 V
Hence for me approx. 8 to 10 K resistance will be needed. I have used 10K resistance.
Assemble power supply as shown in circuit, which is very simple. If you don't get ready made bridge rectifier, make it by using 1N4007 or similar diode.

Important Notes-
1) Working with AC is risky. Using such type of power supply will reduce the life of LEDs.
2) Using a DC supply containing step down transformer, filter & regulator is advisable. Or solid state transformer less pure DC supply circuit will do.
3) You need to design power supply according to input voltage available at you.

Step 6: Gather It Together.

Finally, connect the glass assembly to output of power supply. Extend wires of end cap if needed and connect them to power supply. Connect the end cap. Use adhesive and tape to join the plastic assembly. Its DONE ! Get ready for testing.

I suggest you to use small car inverter or a UPS or a home inverter for testing. Do not use AC mains directly for testing. If everything goes fine, its okay to use with AC mains.

Step 7: Compact LED Lamp Is in Your Hand !

So finally we have made dead CFL working again by using LEDs. The CLL I made consumes about 6W only. It is enough to light up a small room or porch or balcony. Better the power supply you use, better the life of CLL. It costs almost nothing. I needed to spend only 70INR (about 1.5USD) to make this. Let's recycle dead CFLs to CLLs !

Some Ideas
This method can be also applied for Standard Fluorescent Tubes. Bulky ballast assembly can be replaced by power supply circuit. Only the thing is it is very fragile to open end caps of the tube.

If you want to create LED Bulb, you need to carefully open and remove filament in incandescent bulb. Also you need to add a reflected behind of LEDs.



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    84 Discussions


    9 years ago on Step 5

    you mixed up the ac and dc connections on the bridge rectifier Just added a schematic that shows the right connections

    6 replies

    Reply 9 years ago on Introduction

    Diode- Diode is a device which allows current to flow in only one direction. Diode is a semiconductor device. Diodes used here are P-N Junction Rectifier Diodes. Rectification is an important application of diodes. There are various types of diodes like Zener, Shortkey, Tunnel, Varac, etc.

    Resistor- Resistor is a device which opposes the flow of current. It is used to limit the current. Every device has certain capability to handle current. To limit the current for a device, resistor is used.


    Reply 3 years ago

    I am in usa how can I get these led what the name and type? help please


    Reply 9 years ago on Step 5

    you don't say.... when I posted the comment the circuit on the left was in the instructable and the connection on the right is the one I posted then he changed the picture to the one on the right

    altough it does make sense to say the connections are wrong sense he posted the same picture that is to the right into the instructable.


    9 years ago on Introduction

    Good idea!

    The warnings about mercury aside, there are a few things to watch for:

    The 'diode bridge' diagram is not correct. The 2 diodes on the top-right and bottom-left are pointed the wrong way - this is important if someone is to make their own.

    The resistor should have a high power rating. You are using a 10k to drop 156v and P= V*V / R, or (156*156)/10000, which is 2.5-watts. This also means that of the 4.8-watts the bulb consumes, over half of it is being 'burned up' in the resistor.

    4 replies

    Reply 9 years ago on Introduction

    I will correct the mistake (if any) in the bridge rectifier diagram and I have used 2W resistor which is working fine.


    Reply 3 years ago

    what the name of the led you have used


    Reply 9 years ago on Introduction

    Converting high voltage AC to DC to make LED glow is not recommended. Heat is also a factor. Resistors get very hot and the life is short. Unnecessary power is being consumed, Electricty bill goes up. Mercury is UNSAFE to handle.


    3 years ago on Introduction

    you could have used high power led in series coz they are less expensive and you can rely on them....


    3 years ago on Introduction

    Look into a "capacitive dropper" circuit, it's much more efficient than this. Since your load is constant and you probably don't need to add a Zener diode for regulation, you should be able to make it very efficient.


    3 years ago on Introduction

    Ostrożnie w świtówkach tego typu znajduje się rtęć.

    Bardzo trująca!!

    Nie radzę otwierać szkła świtówki, opary rtęci są bardzo trujące!!!

    Oczywiście można wykorzystać świetlówkę jeśli jest sprawna jak i elektronikę,

    ale trzeba zachować wszekie możliwe środki ostrożności!!!!!


    4 years ago on Step 7

    Good idea! Sir., keep it up!!

    me wimpy kid

    6 years ago on Introduction

    i thougt of this idea before but never knew how to open a that i know it,i'm gonna make it with the help of a 1 watt led and led current driver with the help of ur bridge rectifier.anyway,thank u. :D


    8 years ago on Step 4

    Better don't breath at all!
    Oxigen will make free radicals that can (will) produce cancer...

    1 reply

    People here keep talking about the Mercury being released from the CFL, they would do well to remember that there is about 3 times More Mercury in that Tuna Fish that they had for lunch and chased it down with a full serving of tailpipe exhaust from the cars & trucks outside. Then there was the POORLY filtered water that they used to brush and rinse their mouths with JUST before sounding off about how it is SO UnSafe to do this project. forgot to complain about the BROKEN GLASS!

    Come on now....there are a LOT more project listed on this site, whick could do a LOT more harm if you're stupid with it, than this one. We've taken a CFL, which has bad stuff in it, that doesn't work anymore and put LEDs, which are Good, into it and made use of the whole unit...thusly keeping it out of the landfills.

    Top Notch!