How to make your own LED bulbs [Presented by teamTEKFU]you do need a great amount of patience in making this but when you consider the countless hours of purelight -low consumption youll get, its all worth it. This tutorial is about converting regular GU4(MR11)halogen bulbs to LED bulbs while maintaining full usability as 12V light bulbs that can be used in indoortask or accent lighting.
Step one - empty the bulb.Start by taking a small screwdriver and twisting its tip on the white cement youll see around the bulbs pins.This cement is very fine and will start crumbe as a fine powder as you keep twisting the screwdrivers tip.Proceed with this until you get enough cement out for the next phase.Patience is a virtue so take you time and be gentle since the bulbs can easily break if you force you way inwith the screwdriver.
Action time. Take a hammer and after you got out out as much white cement you could, put the bulb face-down on a flat surface. Hit the two pins with the hammer, in a easy but ferm manner. The bulb inside shouldfall on the table leaving the reflector empty.Some white cement will remain but thats OK, its not so important and might even be useful later.Step two - make your holding disc.Put the empty reflector aside since its time to get to another task. Its now time to make the LED support.Youll need a template so make yourself one. I used graphic software to evenly distribute the 5mm holes onthe disc. The disk size is up to you. More leds will require larger disks.Print your template on paper and cut it out with paper scissors. Place it on the aluminium sheet and lightglue it on its surface. This will be useful to cut the disc properly.
Take the aluminium sheet and cut out the holes using a office perforator. I found out mine cuts exactly 5mmholes in paper so for 5mm LEDs its perfect. Keeping it upside down, place the template along with thealuminium disc glued on it inside it. Cut out the holes after aligning the circles in the cutting hole. Thisshould be easy and fairly quick. For this tutorial, Ill use 22 LEDs and a disk diameter of 4 cm. In this pictureyou can see another disk I made for 15 LEDs. Its easy and if you practice a little you can make this inminutes. The aluminium sheet will serve as a light reflector and a holder for LEDs in the same time so take care notto bend it. After cutting out the holes its time to see how the leds should be connected.Go to http://led.linear1.org/led.wiz and fill in the fields with your parameters. Heres a screenshot of whatthe wizard reccomended for my 22 LEDs 12V array. So now I know how to connect them.
Place the aluminium disc in some holding device (I have one like the one in the photo and its great). Becreative with this, basically you have to hold the disc by its outer rims. For example, a pipe section withproper diameter will do. Insert the Leds into the holes with the legs up and arranged in such a manner that one cathode is next toanother anode. This will make soldering easy. Dont forget this or you will have great difficulties solderingthem according to the scheme.
Put one tiny drop of Super Glue on each led margin and continue arranging the other ones. WARNING!Take care not to accidentally apply super glue on the LED legs. When youll have to solder the legs, thesewill be heated and the glue will give off a little colourless smoke with major effects on your eyes! I know,ive done that and couldnt stopped crying for one hour. I think thats how they make that tear gas after all ...After all LEDs are placed and glued, put compound glue around each LED for a solid result. It is necessaryto glue them firmly since the legs will have to be bended and youll risk some leds to come off otherwise.(thats experience speaking) Now let the glue to harden before proceeding. In my case this meant 24 hoursbut the result was worth it.Step three - making connectionsTake one nailclipper and cut out the LED legs, keeping in mind that one anode will have to be bent over tothe next cathode and so on. Also take care not to confuse the two of them. You can check that with onemultimeter set to diodes. As the scheme advises, Ill have to make 5 strings of 4 LEDs each and one string oftwo. Since I arranged the leds in such a fashion that one cathode is next to another anode, this operation ismuch easier. After soldering one string, keep the end legs at different lenghts to easily identify the + and the- end.
Take the nailclipper and cut the LED legs and bend them to the next leg. The + goes to a - and so on untilyou complete a string of four. Then start a new string.When youre done making all the strings according to the scheme, you should have six + legs longer than thesix - ones. Its time to solder the resistors. But first bend the longer legs toward each other and solder them tohave all the + legs connected together. This should be done over the other connections keeping somedistance to prevent short-circuits. The resistors should be soldered vertically to the - legs.
When soldering, try to be as quick as possible sice youll be heating the LED legs close to their base and toomuch heat will damage them. Now solder the resistors legs to each other in order to get a single - that goes to all the strings. Try to keep alow profile so that the whole thing will fit the bulb.Now solder the final legs. Use copper wire (thicker) and keep in mind that one (-) has to be shorter.The whole thing should now be pretty rigid since so many solderings were made.
But for your peace of mind, use a hot glue gun to fill the gaps so that no wire accidentally touches another.This is optional.Now take the empty bulb and put the LED disc inside. The space should be enough if you maintained a lowprofile when soldering.It fits perfectly. Push the LEDs until the disc touches the inner reflector.Hold it still and get the compound glue now.
Just make sure its strong enough since it will be the only thing that holds the bulb in one piece. Fill thespace around the legs coming out of the bulb with as much glue it will take.use a permanent marker to write on the base the + and - legs as well as the voltage it will use.Now cut the legs so that it matches the original bulb legs, equal in lenght.
Job done! Its time for a test. Connect the bulb to a 12V battery (car or anything else providing that voltage).Hold your breath and... Its working! The photo actually does not display the amount of light generated as its blinding if you stareinto it directly.The type of LEDs you use is important since a more dispersed light will be better than a concentrated one.You could also file the LEDs prior to making the bulb so as to have a more uniform light. These LED bulbscan also be used in 12V AC spot lamps if you dont mind the 50Hz flicker. But the best results will come outfrom 12V DC