In this instructable i will show you have to convert an MR16 Halgoen fixture to a LED fixture. I will include the Eagle files that you can send to a PCB house to have the PCB's fabricated. I as well will build these for you for a small fee if you desire.
Before i start let me say a few things about this project. I used a set of Halogen lights from Ikea that were 20 watts per buld and had five bulbs strung across cables hanging across the ceiling. a total of 100 watts per strand. This setup uses aprox 5-6 watts per strand. That being said...... This setup is perfect lighting for some situations/room and not so great for others. You will not be able to brightly light a room with this setup. Its a softer light and perfect for rooms that do not require bright bright light. They have more of a spot effect vs flooding a room with light.
You will also notice in my eagle files that my pcb is not perfectly round. This was an oversight on my behalf. They work in their non round config but if you want perfectly round ones then feel free to edit the file. Really feel free to edit it either way.
See photos for below and after. Next step will include Eagle files for the board house and a list of parts needed.
You can also use 12V batteries with a solar charger for this setup.
Step 1: PCB Files and Parts Needed.
Now on to the parts needed.
Each board uses 12 LED's. I use 20,000 MCD led's with flat tops. You can find these on ebay pretty easily. I paid i think 20 bux for 200 of them.
Each board also uses 4 100 ohm resistors. I use 1/4 watt resistors.
Of course you will need solder and a soldering iron.
Super glue or any other type of adhesive to mount the pcb to the housing and to assist in making the MR16 pins to plug into your power source.
14 guage solid copper wire for making pins. Or if you have access to some other suitable material to use for the pins.
Of course you also need a MR16 housing. These are available at many stores if you dont already have some that you intend to convert. I used a set bought at Ikea.
Continue on to the next step. Taking the MR16 housing apart....
Step 2: Taking the MR16 Housing Apart
To do this i first remove the glass. On the ones im using its as simple as prying out with a small flat head screwdriver. Be careful not to break the fixture.
Once the glass is removed you need to remove the bulb. To do this flip the fixture so the pins are sticking up. Bulb side down... Now use something blunt. I used the grips of my pliers and lightly tap the pins until they push thru and bulb falls out. The white insulation may crumble a bit and that is ok. It is also ok to leave what insulation remains inside. It doesnt hurt anything.
Now its up to you what to do with your bulb and glass cover. i keep mine in case i need them for a future project.
Next step soldering the components.
Step 3: Soldering Components
I soldered on my resistors first. I stuffed all 4 resistors into the backside. The PCB is marked where they will go. After stuffing them in solder them and clip the leads.
Next we solder the LED's. now i did these in groups of six. Stuff three LED's in paying attention to anode and cathode markings on PCB. Long lead is anode(+) and short lead is cathode(-) and then stuff three in directly across from the first three and flip PCB over so the LED leads are accesable. Solder and clip the leads. Now solder in the remaining 6 LED's.
Now you should have PCB's that resemble the photo's below. All that is left is to solder in the wires.
The VIA that is directly in the center is the ground point. This can be found coming off of R3 (there are several ground points actually but this one is easiest). Solder a black wire into this via. Use a gage small enough to fit. ( i inadveratly used a hole smaller than i desired--- you can fix this in the PCB file prior to sending them boards out to make this step easier). Now find the trace coming from the anode of LED 7. You will see a larger VIA coming off of this trace. Solder a red wire here for you 12V input.
At this point you will want to test the assembly. Attach 12 volts. If all LED's light up then you are good to go. If not then you need to troubleshoot why. Perhaps you installed an LED or two backwards or maybe have some bad solder joints. Make sure you have the ground and 12 Voltwire installed to the correct via's. If roubleshooting is needed then trouble shoot and repair. If all is well then we can install the Copper wire that is going to become the MR16 pins that will plug into your final assembly.
To do this cut two pieces of 14 gage solid copper wire about 3 inches.(most of this will get clipped off). On one end strip a very small amount of insulation. At the other end strip off at least an inch or more insulation. Now solder these to the wires already attached to the pcb. Solder to the end that you only stripped a small amount of insulation from. Yes this is a crude way to do this.....
Now that you have both wires soldered you will start to assemble these into the MR16 housing. Paying attention to what wire is attached to ground and what one is attached to 12V. Push the Copper wires thru the pin holes in the MR16 housing. I like to mark the housing with a sharpie with a negative sign(-) on the side that i pushed the negative wire thru. This way you know how to plug them in later. Once you push both wires thru its a good time to do a final test to be sure nothing went wrong with your solder job while installing these final wires. Connect to a 12V supply paying attention to polarity. The side you marked with the negative sign(-) goes to negative and the other side goes to 12V.
Ok now this all works? If not tshoot time.....
If so then your ready to glue it all together. Next step.......
Step 4: Final Assembly.
First place some super glue on the edges of the PCB where it meets the lip of the housing. Or whatever glue you want. Let that set up according to the directions of your glue.
Once that is done add a drop of glue where the leads are sticking out of the MR16 housing. This will stiffen them up and allow you to plug it into the electric fixture. Let this glue dry according to your glue directions. Now clip these two wires down to about a half inch.
Now its time to plug them in and call it done. Now before you do this you need to know the polarity of your light fixture. LED's are polarized after all. So take a multimeter and set it to read volts. Measure the electric fixture you be plugging into and find the positive side. To do this be sure your power is turned on. Now put one lead from your meter into one hole of the electric fixture and put the other lead in the other hole. If you read a positive voltage then you know the hole with the red lead is your positive. If not then switch the leads. Now mark one or the other positive or negative with a pen so you know. Now plug in led fixture paying attention to polarity.
Congrats you just saved your self some money on your electric bill.
I use this set up in my living room and art areas of my house. i went from 200 watts to about 12 watts of power. Its perfect lighting for these scenario's.
I will soon make a setup that is a bit brighter for other rooms such as hallways etc......