You can even take this camping and run it from the car battery. Really shock people to see someone in a dinner jacket reading a book by the light a floor lamp in the middle of the woods.
Someone coerced me into making this instructable, Well actually they've threatened me after the last two times I made conversions like this, without documenting it. And already another friend is asking me to convert his desk lamp to LEDs. My friends kept after me to take pictures and document the conversions for a web page.
So since I have another lamp, and a digital camera handy, I will try to document as much as I can for you.
Step 1: Getting a Floor Lamp
First go out and buy yourself one of those trendy expensive halogen floor lamps...
Hold on there, that's not right. Give me a minute while I go gargle with Ivory soap...
OK, first start watching on trash days for something interesting. Doesn't have to be a floor lamp, the basic instructions here will work just as well with a desk lamp or even a metal mint case (if you want a really small light).
On our last trash day Here I found a nice brass floor lamp with a movable arm so I could use it over my desk with out taking up desk space, that is needed for all my other clutter. Or I could use it behind my chair as I read a nice relaxing book.
But that halogen 100 watt bulb has to go. I've heard them called a dorm torch. If this falls over when it's on, it can easily set loose paper or carpeting on fire.
So let's get right on with the build, with the next step...
Step 2: Gutting the Lamp
Step 3: THE PLAN!
I'm using 12V for my power source, it's easy to find world wide, and as such it's easy to find things to customize to it.
I'm using 3 LEDs in series for each segment, saves on resistors. And a quick word on these resistors, if you don't use them, you will burn out the LEDs.
There are two switches in this project, you may only want to use one, but I'm gonna use two different LEDs, narrow beam high intensity LEDs in the center for a spot light effect, and a ring of lower intensity LEDs for a soft glow.
The soft glowing LEDs only use 10mA of current, while the narrow beam are brighter and draw 20mA. So I had to figure out the needed balancing resistors. I found on line, and so could you by looking for "LED Serial Calculator", a calc that would tell me what resistor to use for three LEDs in series.
To make it simple, if you are using similar LEDs, here are the required values:
120 Ohm for 3 X 20mA LEDs that have a forward voltage of 3.3V
220 Ohm for 3 X 10mA LEDs that have a forward voltage of 3.3V
I'm using 5mm LEDs, and they are round with a ridge that has one side flattened. The lead on that side of the LED is ground, or if you are using new LEDs, the longer lead is positive. With that in mind let's get on with the next step.
Step 4: Making the LED Faceplate
But first a word about the plastic you want to use.
Having a ready supply of sheet plastic is good to have on hand. Personally I find vinyl siding easy to use. It's easy to shape with a pair of scissors, easy to drill holes into, and can be glue gunned into almost anything.
If you know of a construction site that is doing siding, maybe you can get some scrap ends that would normally just be chucked out. But for those of us who live in a more built up area and don't see the construction till after its finished I have a word of advice. Next time you you go shopping at your local hardware store, checkout the colour samples they give out for siding. 'Nuff said, I have a small pile that I was taking home to the wife for her approval.
In this project I'm using two samples with the same colour vinyl back. Normally I'd just use one and shape the corners to fit inside of the lamp's cone, but here I have a ring that can be re-inserted once the vinyl is glued in from the back.
As you can see in the pictures, I drew a couple boxes on the vinyl for where I want to put the LEDs, and I cut the scrap reflector part of the aluminum insert. You don't have to use square boxes, you could make a star pattern, circles, spirals, or even random positioning. But try to remember the more complex you make your pattern, the more difficult it will be to wire up the right LEDs in the right polarity.
I drilled holes for all 36 LEDs, an inside square of 4 segments of 3 LEDs that will be the narrow bright beam. Around the outside square I have 24 LEDs, six per side, or two segments of 3 LEDs per side.
To drill the holes I should have used a 5mm drill bit, but I don't have a metric drill set, so I used a 7/32" bit which is very close. Just a touch loose, so I glue gunned the LEDs into the holes.
Starting from the center I positioned the LEDs so that all the positive leads are facing the same way. I also soldered the required resistor on the positive side of each LED segment. Once the 4 segments were done on the inside, I soldered the ends together so I had just one point to put wires for both positive and negative wires.
On the outside square of LEDs I wanted to make it easier to identify the wires, so I made each corner positive, and the middle of each side the ground points.
Once all the wires are connected, you should only have three wires to connect to the lamp. Unless you are using one switch, then you only need 2 wires. My lamp will have two switches, so I need two positive leads but only one ground. As following The Plan, all segments come together for a single ground lead.
As you can see from the pictures, I cut out the reflector part of the aluminum ring. This has to be done carefully as this was a very soft aluminum, but I went over it with a file till smooth, then hammered it gently flat again.
The vinyl with all the LEDs and wires can now be glue gunned into place, going over the whole outside edge for strength.
You might be wondering about glue gunning everything to a light source. Don't worry, these LEDs don't generate the kind of heat that the original halogen bulb did. Or for that matter, they won't generate enough heat to melt the hot melt glue.
Step 5: Putting LED Panel Into the Lamp
Here I have to apologize I didn't take any pictures of mounting the switches to the lamp body. I'll leave it to your imagination to drill / file / or however you want to make, or enlarge, the holes in the lamp. Just don't use C4 to enlarge the holes, it will leave the edges too ragged.
Here I'm using a special three connector switch that is supposed to light up the duck billed plastic switch on the outside when the switch is turned on. As such there is a third connector for ground. On a normal switch you don't connect ground to the switch.
If you are using a normal switch then just follow the plan in step three for wiring.
At this point I should mention something important. Safety and testing.
During this construction I have been soldering as I went along, and only managed to burn myself twice. In using a regular soldering iron I picked it up by mistake as you would a pen or pencil. And in this step you can see a lighter, it's actually a micro butane torch that I do soldering on wires away from the normal soldering iron. Well that and I use it when I have to solder a large area that the small iron takes forever to heat up. It takes a number of seconds for a large area of metal to cool down once heated to the point of melting solder. I forgot and went to move the wire out of the way so I could do the next.
Also in the line of safety, once all the wiring is done, I put the aluminum ring back onto the lamp body. But before I did that, I taped off any protruding metal wire ends that could ground out against the LEDs. I mean the wires that go to the switch in this case, I wasn't sure if the switches would have enough clearance not to be pressing against the backs of the LEDs.
For those modifying a normal desk lamp with a kind of funnel head, you can just glue gun the vinyl inside making sure to center the vinyl so the LEDs shine straight out of the lamp.
Anyone looking at the photos will notice that I haven't done something yet, attached a 12V power accessory adapter to the end of the wires yet. You will however notice that I have a red tag on one of the wires. That's so I'll know which wire is to be the positive. Through out the build something I did, but didn't document was the constant testing I'd been doing. Checking individual segments with 12V on a couple of alligator clips to make sure I don't have any bad LEDs, or even worse, if I wired one in backwards. With testing I could make changes before the next step. The red tag I put on once I tested the wiring to determine which wire was the positive wire inside the lamp head.
So next, I add the power adapter end, but wait look at that...
Step 6: Midnight...
Step 7: Finishing Up.
I have this nice portable battery that I can plug into my 12V devices. Here I have finished testing the lamp, taken pictures. Now time to think about additions.
There is a number of instructables out there that deal with steampunk, and as this is a brass lamp, it could take some mods, some wood accents, and black painted designs to qualify it as steampunk.
I could add a carved wooden crest to the front of the lamp, maybe add a meter to make it look better, skin the meter in wood. Ow that idea hurt, I could have used a sheet of thin plywood instead of the vinyl. Damn, Damn, Damn.
Final note, before someone asks, I did meter the lamp out and determined that it draws 0.3A at 12V that is 3.4 watts. YES! I replaced the 100 watt fire starter with a 3.4 watt LED lamp. That's gonna save on power. Even more if like me, you use solar cells to charge up a deep cycle battery to run lights like this.