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After moving into a new apartment I was faced with a full set of white-hot, inefficient halogen ceiling bulbs. The fixtures use the 12 volt DC MR16 standard, taken from the mains after being converted from 120 AC. They’re controlled by the light switch right next to the front door, making them essential for navigating a dark room when first arriving home.

While there are LED alternatives on the market for this socket type, the technology is still prohibitively expensive. I pulled one of the halogens and found the socket was simply two pieces of 19 gauge wire. I decided to free-form some circuits made of different colored LEDs around the thicker terminals.

Depending on the color and the amount of LEDs used in a circuit, the resistance needs change. Unless you’re an electrical engineer, you’ll probably find that an online LED circuit calculator comes in handy.

Once you have them all soldered together, check the polarity on each fixture with a test circuit. The fixtures are designed to only work with a load, so I used a small DC motor and noted the proper direction of rotation. Then, with the lightswitch turned off, carefully plug the 19 gauge wires into the sockets and switch them on.

The result is a soft and ambient illumination that lights my way when coming home. If I need it brighter I switch on some lamps in the room.

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Michael Colombo

In addition to being an online editor for MAKE Magazine, Michael Colombo works in fabrication, electronics, sound design, music production and performance (Yes. All that.) In the past he has also been a childrens’ educator and entertainer, and holds a Masters degree from NYU’s Interactive Telecommunications Program.


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Comments

  1. Despite the hand-soldered “freeform” nature of this – some would even call it a hack, I think this is VERY elegant.

    Not only does it lessen his energy usage, it also stops the room getting so hot (anyone who has ever had to work in a low-ceilinged room under halogens will hear this loud and clear), and gives a nicer, more diffuse (due to the many light-sources) light for the room.

    On top of that, since he hasn’t actually soldered them into the fittings, come moving-out time, you remove the LED’s, which probably cost about $5 in total I imagine, and re-insert the old halogens, and you’re sorted.

    All in all, nice.  Wish I had haolgens fittings.

  2. Despite the hand-soldered “freeform” nature of this – some would even call it a hack, I think this is VERY elegant.

    Not only does it lessen his energy usage, it also stops the room getting so hot (anyone who has ever had to work in a low-ceilinged room under halogens will hear this loud and clear), and gives a nicer, more diffuse (due to the many light-sources) light for the room.

    On top of that, since he hasn’t actually soldered them into the fittings, come moving-out time, you remove the LED’s, which probably cost about $5 in total I imagine, and re-insert the old halogens, and you’re sorted.

    All in all, nice.  Wish I had haolgens fittings.

  3. Despite the hand-soldered “freeform” nature of this – some would even call it a hack, I think this is VERY elegant.

    Not only does it lessen his energy usage, it also stops the room getting so hot (anyone who has ever had to work in a low-ceilinged room under halogens will hear this loud and clear), and gives a nicer, more diffuse (due to the many light-sources) light for the room.

    On top of that, since he hasn’t actually soldered them into the fittings, come moving-out time, you remove the LED’s, which probably cost about $5 in total I imagine, and re-insert the old halogens, and you’re sorted.

    All in all, nice.  Wish I had haolgens fittings.

  4. Ken Fehling says:

    Wow cool. Makes nice mood lighting. LEDs are great little things.

  5. Anonymous says:

    Swap the green and yellow and you’ve got the Microsoft Windows logo ;)

  6. James B says:

    I built almost this exact same thing about 20 years ago, but never put it on the ceiling.  I got some clear casting resin from the hobby store, and put the whole array of LEDs into a hemispherical mold.  It glowed nicely.

  7. Paul Ahlquist says:

    Add a full-wave bridge in the power rails and worry not about polarity.  You’ll need to account for the extra diode drops to keep the max brightness to original intent.

  8. This is great fun. I have build a lot of these led lights. Keep up the good work!

  9. Reynier says:

    You were way ahaid of Philips that has recently launched a similar product, but then much easier to install :)

  10. Led Lampen says:

    They look very nice, I like LED!

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