It's been almost a year since I started to "LEDify" my home, with results more or less encouraging, but only an accident made ​​me find the best solution so far.

Step 1: Motivation

How often happened that you or someone in your family, by mistake, to overthrow the desk lamp? If you are like me, this has happened many times...  For this reason, the last time my offspring slammed my desk lamp one more time, with an innocent "UUPS!", I exclaimed Enough!

Warning! CFL bulbs contains a small quantity of mercury and this is a very toxic substance.
If by accident or intentional, you have broken an CFL bulb, it is advised to ventilate the room as good as possible, in order to dissipate the toxic vapours.

I decided that I have to replace the CFL bulb from the desk lamp, with something more shock resistant...

But that could withstand the treatment of a 10 years child and at the same time to make enough light to work at desk in good condition, to be reliable in operation and decently priced? If only a few years ago, there was no a solution to this question, the answer is now clear: a power LED.

Step 2: Materials

As I already had some Cree MX6 Q5 LEDs with 3W power and maximum light output of 278 lumens used in some older projects, I decided to use them for this project too. The LED will be placed on a 5cm x 5cm heat sink recovered from the chipset of an old computer motherboard.

For simplicity, I decided to use a switching power supply of a mobile phone, perhaps together with an electronic adapter that would give me the necessary voltage and current to power the LED. For this purpose I have chosen the power supply of a defective mobile phone Siemens A52 having, according to the manufacturer, an output voltage of 5V and a current of 420mA.

An socket from am old CFL bulb should protect all the electronics.

Step 3: EVRIKA Moment

According to manufacturer specifications, Cree MX6 Q5 LED can be powered at maximum current of 1A at a voltage of 4.1V, and I expected I'll need a 1 ohm resistor to lower the voltage by about 1V from the 5V (given by the power supply) to the 4.1V accepted by the LED, and that only if the power supply would handle the maximum current of 1A.

In order to check the maximum current supported by the power supply I connected to his terminals various resistors, measuring in each case the voltage and then calculating the current. Here are the obtained values:

Load            Voltage          Current
-NA-                5.8V            0A
8.2 ohm         4.9V            0.6A
5.1 ohm         3.1V            0.6A
3.3 ohm         1.75V          0.53A


To my surprise, the power supply seemed to have by construction the current limited to about 0.6A, value he looks like it stand without problems. Testing in the same way other mobile phones switching power supplies, I found that absolutely all of them are limited by construction to a current from 20% to 50% higher than the one specified by the manufacturer, which now I find it makes perfect sense: any manufacturer will design the power supply so that it will not overheat even if the powered device would be damaged, even in short circuit ... and the easiest way to do this is by... current limiting!

I had therefore, a constant current generator limited to 0.6A, very effective (a power adapter cell phone heats up only slightly during operation), powered directly from 230V AC, ready-made by the factory, with very small size. And this is simply GREAT.

Step 4: Construction

For the beginning I made "the autopsy" of the power supply in order to extract the "organs" to be inserted in the body of the new bulb. As most power supplies are assembled by soldering, extracting consists of cutting with a saw blade... So pay attention to bruises for those less skilful...

In order to fit inside the body of the lamp, it was necessary to make some adjustments.

To fix the board inside the bulb, I used sanitary silicone, taking advantage of its resistance at high temperatures. Before closing the bulb, I attached to the cover (I used a screw) the heatsink on which is located the power LED.

Step 5: Results: Desk Lamp

And here's the bulb assembled. The power consumption is just under 2.5 W and the luminous flux is about 190 lumens, perfect for a economical, durable and resistant desk lamp. And all this for up to one hour of work, except of course the time for drying the silicone and heat-conductive adhesive used to fasten LED on the heatsink.

I was so excited about the success and ease of implementation of this project that after a few hours I had finished another LED bulb.

Step 6: Results: Hallway

Thrilled with the result, I continued to replace some of the CFL bulbs in my apartment with LED bulbs constructed in the same way. I will present these in "fast forward"...

For the entrance hall I used two Cree MX6 Q5 LEDs each having maximum power of 3W and maximum light output of 278 lumens, each powered by a power supply from old Samsung mobile phones. Although the current specified by the manufacturer is 0.7A for each power supply, after measurements I found that it is limited to the value of 0.75A.

Everything was assembled with velcro tape, adhesive and plastic spacers from PC motherboards.

Total consumption of the assembly is this time around 6W for a luminous flux of 460 lumens.

Step 7: Results: Bathroom

For bathroom I used an Cree XM-L T6 power LED, powered by using two switching power supplies from LG mobile phones. Each power supply unit can generate according to the manufacturer, a current of 0.9A, but I found the current practically limited to the value of 1A. The two power supplies are connected in parallel for a total current of 2A.

Under these conditions the LED will produce a luminous flux of about 700 lumens for a power consumption of 6W.

Step 8: Results: Kitchen

If for the hallway and bathroom was not essential to ensure a certain minimum illumination, for the kitchen is a different story. I do not want that my wife or someone else to cut a finger while preparing meal and blame me for this, or worse, blame my precious LED bulb...

To make sure that this will not happen, I decided to use for my kitchen, not one, but two power LED Cree XM-L T6 each having maximum power of 9W and maximum luminous flux of 910 lumens, connected in series. For efficient cooling I used a heatsink recovered from a Pentium 3 Slot 1 CPU, which I attached the two LEDs using Arctic Alumina thermal adhesive.

Although Cree XM-L T6 LEDs can handle a maximum current of 3A, the manufacturer recommends for reliability a current of 2 A, for which they produce a luminous flux of about 700 lumens. After testing several power supplies that proved not to be current limited or limited to a current well above the necessary 2A, I managed to find a power supply which, according to the manufacturer, generates 12V at a current of 1.5A. After testing it using power resistors, I found the current limited to the value of 1.8A, quite close to the planned value of 2A. Perfect!

To secure the heat sink and the two LEDs I used two plastic spacers from a PC motherboard and two neodymium magnets recovered from a damaged DVD drive, all glued with superglue and also a velcro tape.

Although I expected this LED bulb to produce 1300 lumens, a light similar to the old 23W CFL bulb it replaces, I had the pleasant surprise to see that in reality the light produced is visible more intense, all for a power consumption of about 12W, almost half compared to the old bulb.

Step 9: Conclusion

The coolest part of this project is that you can use commonly available components, the only expense is for purchasing power LEDs.

In this way, you can get LED bulbs at a cost of half or even quarter compared to the price of an LED bulb purchased from a store.

I hope that in this way many power supplies from mobile phones will be useful again instead reaching the trash can.

This project is extracted from a series of articles published on a DIY web site I own http://www.schematics.ro/ where you are more than welcome.

Thanks for reading :)
Salut explica si in romaneste te rog
<p>Great one, thanks!</p>
<p>se cunoaste ca esti roman.....dupa explicatii</p>
my first led flood light 40W@12V
i want to start led bulb business on my own name in india..<br><br>can anybody tell me about cheap and powerful led bulbs manufacturers/ supplers in india so that i can start the business.<br><br>my contact detail is aiftikhar21@@gmail.com<br><br>cell No. 923335255121
<p>i want to start led bulb business on my own name in india..</p><p>can anybody tell me about cheap and powerful led bulbs manufacturers/ supplers in india so that i can start the business.</p><p>my contact detail is negijagpals@gmail.com </p><p>cell No. 710009876</p>
Where can you get the replacement LED light ?
Yes, the heat sink is required... without it, the LED will have a very short life span... The heat sink is not required when the power of each LED is very small... let's say 0.25W (like in LED strings)...
<p>hi</p><p>you say about heating problem but i give my another product such this to my friends for long time may be 4 years ago and he was use it in bedroom in room temperature for long time approximate all along nights and he wont told any problem for its performance and yet it work fun and just led chip show a little decrease in brightness that every one cant not be recognized it with his eyes however experts may found it but it work.</p>
<p>Great! It is sturdier than I thought :)</p>
<p>Ah... the lamp shape is great, because of the cover it won't hurt your eyes if you look directly to it. However you have in the same closed enclosure, both the LED which produce a lot of heat and the power supply which is affected by the heat (it contains sensitive electronics). If you only use this bulb for short periods of time (in the fridge) it should be ok. Otherwise you might have an overheating problem.</p>
<p>hi</p><p>excuse me tudurache i want you just to say about my lamp bulb shape because i create it with my own idea!</p>
<p>hi</p><p>how many concession you give me for for my innovation while you see my hand made products for it size and shape in pecent?</p>
<p>I didn't really understand your question... sorry</p>
<p>hey dudes </p><p>i made 1 watt led for my refrigerator i use chines 1 watt driver and one chines 1 watt led (market JBZ) with an old broke corrupted &quot;sleep-light color change&quot; body that have ultra low bright and my new handmade that it produce 90 lumen that enough to bright in classic 12 foot refrigerator just consume 1 watt and work for long time may be 20 year ,can u develop such this for 1000 - 2000 lumen output in just consume less than 15 watt? </p>
Hi,<br><br>It'a a bit too much for such a small body... maybe one or more strings of leds connected in series powered by a capacitive reactance power supply (it won't produce any heat). It will not be isolated from mains power supply but you could do the job...
<p>h..</p><p>yes i found why my comments are empty.....</p><p>i read cree led components and i see if use new cree led X LAMP- XP-L to get more brightness and have more efficacy due to developed chip and newer technology it give 200 lumen per watt in 350 m.A meant that lamp get 600-800 lumen flux</p><p>and may be grow project to have more bright and less consume</p><p>cree in leader in led worldwide another is Phillips and other have play less role in this industrial and they have competition to try new lumen per watt integer and almost ones win the match if in today we see cree is ahead!</p>
Hi,<br><br>Yes, Cree realy makes great products, a bit expensive but worth every penny... In my ligting projects, the overheating is by far the most vrequent cause of failure, but with Cree leds having such a good efficiency, the heat is not a problem.<br><br>Regards
<p>why you try to remove my comments?</p>
Huh??? I guess only the owner of a comment can remove it's own comment... and the admin (instructables employee) if you break the &quot;be nice&quot; policy...<br>And believe me... even if I could to do so, I have better things to do...<br><br>Peace<br>
<p>a fab idea and replacement to CFL's in very cheap price.</p>
<p>interesanta idee! totusi nu se incalzesc prea tare radiatoarele alea mici de chipseturi?...</p>
Cu radiatoarele de chipseturi nu am avut probleme, oricum LED-ul e alimentat la sub 2.5W si la puterea asta temperatura nu trece de 60 grade. Deja de am de mai bine de 2 ani si merg fara probleme. Mai degraba alimentatorul telefonului pare sa fie sensibil la caldura... am niste becuri cu leduri chinezesti de 10W la care mi-au crapat alimentatoarele. Radiatorul desi e de CPU incalzeste si alimentatoarele si asta le cam afecteaza... e vorba de proiectul de aici: http://www.schematics.ro/Projects/LedLighting6.aspx
Is there any diagram of your design for us to uderstand more easily?thank you sir.
<p>Cut the phone end of your mobile charger. Solder the red wire with the + terminal of LED. And respectively the black wire to the - (negative) terminal.</p><p>Connect the phone charger to power socket and enjoy the illumination. </p>
Well... it's not realy a diagram... only the LED and the phone charger... connect &quot;positive&quot; from the LED with the &quot;positive&quot; from the phone charger, and the same with &quot;negative&quot;. No other component is required :)
<p>Bravo tudurache and thank you for sharing.</p>
<p>Thank you for taking the time to make your website available in english.</p>
<p>Hi Great project, I really like the lamp cover you used in the bathroom version. Just curious - did you make that painting/pattern or find it somewhere (if found...where?)?</p><p>Thanks!!!</p>
I'm glad you liked the project.<br>The lamp cover (together with the lamp itself) that I have used was bought from one of the local stores here in Romania (Dedeman: http://dedeman.ro/) but you might find something similar in other places...
<p>As i have 1W LEDs with me, can i connect 3 Leds a charger as parallel line. Pl reply.</p>
It's not recommended because the LEDs could be slightly different in parameters and the current will not be evenly divided between the three LEDs. However if you have to do this, you could connect in series with each LED a 2.2ohm/1W resistor.
Dude, you have got to look into LED drivers, they are really quite cheap, more compact, and safer for the LEDs.
Dude, it's all about recicling... if I can use that I already have, then why spending money for LED drivers?<br>I doubt that those are more compact and safer than a phone charger... I know many dudes that keep them powered for years and none of them caught fire or even broken.<br>And they certainly are more expensive than a regular phone charger. If you already own a phone charger (cost is 0), the LED driver shoud be more expensive by... you count how many times...<br>Mine already works for 3 years and I didn't have any problems so far...
If you already have a phone charger then absolutely use it. But as for the LED drivers being bigger and more expensive, that little circuit on the heatsink in the first picture is the driver I bought. They are definitely smaller, and I got it for about a buck, so around the same price for a low-end phone charger. However, I did not mean to put down your 'ible, in fact I actually love the idea. And made one myself, pictures 2+3. And I use it a lot. So great idea, and great result, but for those of us who don't have a bunch of phone chartered laying around, LED drivers are an idea.
<p>You're right, if you don't already have a spare phone charger instead of buying one, it's better to buy an dedicated LED driver. But almost anyone has some spare phone chargers, and using them saves the money and the environment.</p>
<p>Hi Tudurache</p><p>I love your work and ideas! Recycling from old electronic parts is genius. I have a quick query, do you think it would be possible to power up to 15 Watts worth of LEDs? I have many 14 W 2D lights that have failed drivers in them, I don't know which component within the driver has failed and really want to be able to replace or repair them. Any ideas?? </p>
<p>Good afternoon for all bodies</p><p> It's a nice project I will to make this lamp</p><p> Thank you for all</p>
personally I find the color of the Q5 LED to be much too green without much blue to even it out. But then again I have blue CFLs for the main source of light in my room<br>nice bulbs.
<p>Its an awesome idea to use the cell phone chargers to directly power the LEDs without using wasteful resistors. Can you please advise the best configuration using 1 W LEDs. Do you think that I can directly connect 2 x 1 W LEDs in parallel to a cell phone charger?</p>
<p>1W LEDs requires about 300mA but phone chargers generates usually more than 700mA... so connecting 3 or better 4 * 1W LEDs in parallel should work, but in order to equalize the LEDs characteristics it's recommended to connect in series with each LED a small value resistor... about 0.5 Ohm or 1 Ohm (1W) should be ok.</p>
<p>Not sure about LED's and electronics but was wondering what it would take to have substantial power supply central place in a house and wire all led lights around house. Would love to remove most outlets and replace with USB connectors to power charging and LED based lighting. You are saying something about the maximum output of the power supply burning out the LED if it is over the rated level for the bulb.</p>
<p>It could be done, but you'll still need a constant current source, for each LED bulb, and this could be more expensive than a phone power supply that you probably already have lying around.</p>
<p>Very informative and useful post by you. This can be a very useful to make a cheap but very powerful LED bulbs. There are so many electronics store which offer the best LED bulbs or lights. To get more information you can visit <a href="http://www.analogtechnologies.com" rel="nofollow">www.analogtechnologies.com</a> .</p>
<p>u r to good</p>
<p>Thanks my friend :)</p>

About This Instructable




Bio: I am an Romanian computers engineer, with a passion for DIY for over 25 years. I just love to make useful things by using scraps ... More »
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