In this instructable I will show you how to construct a LED light in an Altoid Container. This light is very compact and rugged, it can be powered by multiple power sources.
These could be anything from a set of rechargeable batteries, a cigarette outlet in your vehicle or a portable power pack. A solar charged pack could be used as well.
The pack is based on some very inexpensive items that can be purchased on Ebay with relative ease.
You will need the following:
1. An empty/clean Altoid container.
2. A small "Buck Boost Converter" similar to the one pictured at this link. http://www.ebay.com/itm/Auto-DC-DC-Boost-Buck-Converter-Solar-Voltage-Regulator-25W-3-15V-to-0-5-30V-/221264404431?pt=LH_DefaultDomain_0&hash=item338462dfcf
3. An LED (light emitting diode) array of your choosing. I chose the following due to its voltage, size etc. Here is a link to a 48 LED SMD (surface mount device/component) very similar to the one I used. NOTE *** if you buy these in bulk, say 5 or 10 at a time they are even less expensive. http://www.ebay.com/itm/48-SMD-LED-White-Light-Panel-Interior-Bulb-T10-BA9S-Adapter-Festoon-Dome-Lamp-/370895869041?pt=Motors_Car_Truck_Parts_Accessories&hash=item565b1dd471&vxp=mtr
4. An off / on switch also available on Ebay. keep it small so it fits in the box !
5. A fuse of what ever type you wish. as you can see I used a very simple set up.
6. Some connecting wire. Approximately 2 ft of wire will work.
7. Shrink tubing or electrical tape will work.
8. A male cigarette plug or what ever plug or coupling you choose, such as Anderson Power poles etc.
9. A soldering iron, solder, and NON ACID flux will be essential in this project. A pair of wire stripper or a knife,a drill and bit set will be helpful as well.
10. Lastly 2 items, a DC voltage multi- meter and a small jewelers/ glasses style flat blade screw driver to make adjustments in voltage.
Step 1: Prepping the Altoid Tin
In this step we will be drilling two holes. Start with a smaller drill bit than needed, use this to pilot your holes and finish will the larger size bit that you need.
I drilled the holes just one size bigger than the shank on the switch and the opening for the size wires that need to pass through. Bare in mind these holes may be different given the wire size you use as compared to the switch shank.
**** IMPORTANT*** Make sure that the shank and nut on the switch will clear the lid of the container when the top is closed !
Mount the switch so that both and open and closed terminals can be accessed easily for soldering purposes.
Form your cable as you see in the picture so that it can easily be soldered in place.
(NOTE on all wires that have been stripped and ready to solder, make sure you tin them so that soldering will flow easy. This also keeps the multiple strands together and things turn out clean and neat !)
NOTCE If you will the small piece of shrink tubing over the wires coming out of the tin. This is to protect the wire from accidentally shorting out on the edge of the tin. Shrink tubing can be shrunken into place with a lighter held under or next it to it. **** WARNING*** Be careful with fire and KEEP THE FLAME MOVING dont get to close to the shrink tube or it WILL CATCH FIRE << NOT GOOD :) .
Note I am not responsible if you mess this up or get hurt, be careful !!!!
So shrink the tubing, cut and tin the wire ends after tying the knot. At this point you can feed it through the hole.
There is more than one way of securing the wire. the inside knot I feel is essential, but an outside knot will also help if you are so inclined. Personally I mixed a small amount of JB-Weld expoxy and used to make the whole/cord connection more water tight.
Mix the JB-Weld and let it set on your mixing pallet. (paper plate, junk mail etc) and after 5-10 minutes from stirring, apply some to the joint. This will have allowed the epoxy to set up a bit and keep it from dripping off the tin.
****** NOTE***** at this point the tin should be on a surface that will catch excess epoxy. new paper, paper bag, junk mail etc.
Step 2: Soldering / Crimping the Parts Together
You will notice the positive (red wire) is shorter than the black one. this is to allow it to bend around and be soldered to the switch easier.
You will solder the red to the switch and the black one will be crimped to the spade to hold the fuse in place. If you choose to buy a pre-made fuse holder you will just solder it in series with the black (negative) wires instead.
NOTE in crimping the fuse spades, strip and tin the black wires then fold them back 180 degrees against themselves. this helps fill the spade connector and assure there will be enough content to keep it in place after crimping is complete. << This is very important or your wire may release from the crimp joint.
After inserting the fuse I chose to insulate the connection by applying electrical tape to it. Choose what ever color you wish, I just thought white would show better in the pictures.
Step 3: Adding the Buck Boost DC/DC Converter
FIRST OFF some theory about the Buck Boost Converter:
Note this is a BUCK BOOST not just a Boost or Buck converter there is a difference. This converter both raises and lowers voltage. The others do one or the other.
Once you understand what the device does you will further understand the usefulness of the project!
A Buck Boost Converter simply put takes what ever voltage you put into it, (in this case 3-32 volts DC) and outputs what ever voltage you set it to. I.E. if I have a 12vdc LED panel, I can set the converter to say 11.5-12 volts DC with my multi-meter and that is what will come out. Now the good part is this!
If I put in 18vdc it will spit out 12vdc, if I take a 9vdc battery or a 6vdc battery and input it, the converter will convert amperage to voltage and put out 12vc. period.
Therefore you can use up old batteries, odd voltage inputs from a small solar panel, an old wall wart (DC transformer), any number or sources and the converter will just change it over to the 12vdc that the LED needs to run.
Could you picture how this might be helpful in an emergency where you have not good batteries left, even your car battery might be fairly dead.
***** NOTE***** Buck Boost converters are fairly efficient in the 90% plus range. The efficiency goes up the closer your supply voltage is + or- from the LED supply voltage. SO..... If your supply voltage was from say 9vdc to 14vdc the efficiency would be higher than 4vdc converting to 12vdc. Bare in mind also if there is not enough amperage available at 4vdc to convert to 12vdc the LED will not turn on!
Moving on (yes I get wordy but I think it helps beginners).
Before you do anything else be prepared to put a piece of electrical tape or some other insulator under the converter after soldering. You don't want to short out the connections under the circuit board on the Altoids tin.
You have been warned! :)
Looking at the converter out of the package you will see terminals/solder pads at both ends of the board. pay special attention to what is printed on the board ends. One end will say IN and the other OUT. i.e. voltage supply input and voltage output >> to device LED etc.
Also note that both ends next to the solder pads it will have an (- negative/black wire) pad and a (+ positive/red wire) pad. make sure these get hooked up right THE FIRST TIME!
With these converters most do not have polarity protection. if you hook it up backwards ZAP IT'S TOAST, DEAD!!!!
You will want to solder the red wire from the switch to the + input side of the converter. Solder the black wire coming from the fuse to the - side of the input.
On the output side ( I made a short connecting cable) solder the red wire to the + out and the black wire to the - out.
Important !! You will see a blue 10 ohm resistor on the positive + side of the output, OF MY PICTURE you will not need that. I put it in there to experiment with an idea and forgot to remove it before taking the picture!
AGAIN do not use a resistor on the positive output!!
I then soldered the LED wires (with shrink tubing already on the wires) , red to red and black to black. after doing that I slide the heat shrink tubing over the connections and applied heat from the lighter to shrink it in place.
Step 4: Help With Soldering
SOLDERING 101 By Bryan
In my life time I have had so many people talk to me about how it is so hard to solder wires, circuit boards, pipes etc.
By way of background I have worked previously in the electronics industry where I soldered day in and day out. At one point I was soldering fine connections on instrumentation that flies in the International Space Station.
I have been a gold/silversmith with 18 years bench experience and have learned to flow all manner of metal, solder etc.
The one thing I have found is that metal is pretty much metal! Some is easier than others to work with but by and large the process is the same.
1. Clean metal is an absolute. If the metal is oxidized or dirty the solder will not flow no matter how hot you get it.
2. With out the presence of some sort of flux the metal will oxidize while you heat it and again the solder will not go where it is supposed to.
3. DO NOT attempt to solder with just the core solder containing resin flux inside. I have found there is NEVER enough flux in it for a good joint to take place. By the time the flux gets warm enough for the resin to flow the metals are already oxidized.
4. Buy a good quality of non-acid paste flux. You can use a small screw driver or tooth pick, maybe even the non used end of a chop stick to apply it with. Cover all surfaces to be soldered. It won't take much but as long as they are covered oxygen can not access them before the solder has a chance to make a molecular bond.
5. I prefer not to use thick solder. It is bulky, hard to manage has a weird tendency to melt off all of a sudden thus it is hard to control. It is okay for sweat soldering cooper plumbing but for electronics projects it is nothing but a headache.
6, Remember to tin the tip of your soldering iron or gun. This means making sure the tip is clean, then fluxed , then solder applied to it while hot, just before you make the joint. Having the tip clean is just as important for heat transfer as the objects you are attempting to solder.
7. I keep a wet/ READ DAMP sponge at the table/bench. I often will place it in a shallow dish similar to what holds a pillar candle, LOW SIDES so you can get into it.
I dedicate this sponge only to soldering. Get the sponge wet with mildly warm water and squeeze it out about 70% thus leaving a fairly damp but not wet sponge. This sponge is an easy way to clean a tip. Once the tip is hot you can dip it quickly in the flux and wipe it on the sponge in a backward dragging motion. you should see a shiny surface appear in which you can use in the project.
8. Often you will need to clean the tip between each joint. doing so allows for better heat transfer from the iron to the work.
9. I try to secure the items to solder so they are lapping over one another such that when the solder flows they will be joined together with out a lot of moving things around.
10. Remember (THIS IS A BIGGY) put your heat where you want the solder to flow to.. the molten metal solder will go in that direction. Remember physics is on your side. HEAT RISES! so if you have two wires that you are joining together put the heat under the wires and move it back and forth lightly touching the wires. With the other hand feed solder from the roll into the joint
as it joints you will see capillary attraction take place. you will see a joint that look something like this )II( where the solder had formed nice round curvatures between them with solder.
11. DO NOT quench the solder joint with a wet towel or sponge too quickly. In certain cases where you are soldering heat sensitive parts like a small transistor or diode you might want to cool it quickly. As for just wire joints give them about 3-5 second to bond first then cool them. You will obtain a much better solder bond. quenching to quick can cause the metal/solder to freeze to fast loosening the bond between them.
12. If you used a lot of paste flux it is good to take a damp paper towel or sponge and gently wipe the excess flux off of the connection. This makes it neater, cleaner and prevents corrosion should it want to happen as the joint ages over time or from current going through it.
13. If you have specific questions about soldering feel free to post or write to me and I will be happy to assist you as best I can over the web.
14. You will notice in the picture above containing the solder joint that the solder was sucked down into the twisted wire joint. The wire I was soldering there was phosphor bronze a very tough metal, hard to bend and work with. That joint was done with a Harbor Freight Butane Pen torch. The torch allowed me to create enough heat to make the joint flow correctly. If the junction does not reach a proper temperature the joint will be cold (Not strong or stable) also not a good electrical conductor either.
Step 5: Mounting the LED Panel
I chose to buy an LED panel that had the adhesive (double sided tape) already attached to the back of the panel when I bought it.
This saves time and money. I found it to be perfect for this project as you dont end up with a $5 roll of double sided tape that you might not need or want.
I swapped around the way the LED was laying in the Altoid in top so as to make the wires flow better. Use your own judgement on this depending on how you mount things and the light you use. My way of doing it is just a suggestion.
Line up and stick the LED/light in place making sure it is away from the tin top edges and will also clear the converter/fuse when it closes. You don't want to have it all finished and close the lid and hear it go CRACK!
Step 6: *** IMPORTANT*** Final Step Adjusting Voltage
BEFORE plugging in and turning on, UNPLUG the LED/light panel.+to+ and - to - .
Set your meter to the DC volt range and turn it on.
Now plug in the Cigarette lighter plug or wall wart etc. Read the meter connected to the output side of the converter and see the voltage.
Take your jewelers screw driver and turn the small brass screw on the adjustable rheostat (In My case the little blue rectangle box) until the voltage is set to the voltage you want at the output or slightly lower.
Now plug in the LED panel and after the light comes on, and (You don't see smoke meaning you hooked it up wrong), apply the meter again and make a final adjustment up or down to get the voltage under load set to where you want it.
*****NOTE****** If you want an LED to last longer, slightly under volt the light. For instance if the light is for 12 volts DC set it at say 11.5-11.8. It will shine just a tad bit dimmer but the LEDS will last a lot longer and thus be more reliable when you need them most.
So now you are done and have a working LED Emergency / Camping light.
For those of you who are Ham Radio operators, I use on of these in my emergency GO BAG/BOX it is very helpful in rough night conditions to set up Radio equipment for emergency ARES operations etc.
****** NOTE ******
Also a couple of the pictures show the converter out of the box while I was adjusting voltage. These lights are VERY BRIGHT don't look right at them they hurt. I ended up putting a thin sheet of opaque plastic over them to make them tolerable. :)