The Coolest (and smallest) 9V LED Flashlight ever

In this tutorial describes the step by step process to build a very efficient, small, simple, long-lasting and cool LED flashlight. This is a very simple project, so I encourage anyone to attempt it. Here goes...

1. The Parts

What you will need:

1. Rugged plastic 9v battery clip (also called a PP3 clip)
   
2. Push button switch (aka a Tact switch)
3. Jumbo (10mm) LED or a really bright 5mm LED (choose super- or ultra bright)
   
4. The proper resistor(s) for your LED (I'll show the calculation)
   
5. 9 volt battery, of course
   
6. Some hot glue and a glue gun
   
7. Lastly, a soldering iron with some solder

The 9V battery clip, LED(s) and resistor(s) can all be purchased at almost any electronics store like RadioShack. My push button switch came out of an old (broken) VCR - check out some old junk and broken electronics. They usally have buttons that click, and you will probably find some satisfactory switches inside. You could always buy them new if you wanted to (see digikey.com). If you are going to get your switches out of something old, though, you will need to use a "desoldering iron" to remove it. A simple solder sucker works just as well.

Figure 1 : Before and after

2. What LED and resistor(s) to use

For my design, I used a large (10mm) red LED, because it would be very useful to use it on campouts (the red won't ruin your night vision). O and also, because I had it on hand. If you are making a light that you can actually hope to use, then I suggest using a stronger LED that has a higher lumen or millicandella rating (several thousand millicandella (mcd) would be better). These LEDs are not as bright as Power LEDs (see my other tutorial here), but they are cheaper too. I had some strong LEDs here that have 10,000 mcd! Now that's bright! Remember that you should use a resistor in series with a LED, to limit the current and thus protect the LED. But how can we calculate which one to use? You could do it yourself, but then I would have to explain the steps. Rather go to this site and have it done for you.

Figure 2 : Disassembled

3. Putting it all together

Now that you have all the parts you need, it's time to get building (aka the fun stuff).

The easiest, and probably quickest, way to go about this, would be to use the glue to fix the switch, LED, and resistor in place before doing any soldering. If you did this, you can cut the PP3 clip wires to just the right length. Your friends will be impressed with your soldering work. Now, do the next steps WITHOUT the battery clip on to the battery terminals.

Use a wire stripper (I used my teeth) to strip a little bit of plastic off of the ends of the wires, after you have cut them to the perfect length. Next, dip them in flux and tin the wires with some solder. This will make it easier to attach when you're making the connections. The flux will make the solder spread nicely and evenly all over the wire.

Look at the LED. It will have two leads coming out of it. One will be shorter than the other. That one is the negative terminal, the other one is positive. Sometimes the plastic of the LED will be flat on one side. This is the negative side.

The rest is rather logical. Connect the red wire to the positive lead of the LED. Connect the black wire to one of the four legs coming out of the switch. Solder the resistor to the leg that is diagonally across the switch (from where you connected the black wire). Then connect the remaining end of the resistor to your LED. Check to make sure you connected everything correctly. And then cut off the extra two legs on the button switch that you didn't use.

Put on some more glue to make sure everything is on properly. I added some red tape around the battery for the looks.

Thats it! Finished! And you have just made yourself one heck of a great beginners LED flashlight!

Figure 3 : It's alive!!!

The Ultimate Power LED Head Lamp

This Tutorial shows you how to build a 8 Watt, 500+ lumen LED powered headlamp. It is a great alternative to buying a brand name headlamp, which is much more expensive. Lets start with the specifications of the finished product followed by the required parts.

1. Spesifications

1. Brightness: 500+ lumens / 7 million+ mcd @ 15 degree
2. Weight: 120 gram headlamp + 60 gram electronics + 280 gram battery pack = 460 gram total.
3. Cost: $60, including the batteries
4. Battery Lifetime: 3, 6, 12, 24 hours (4 brightness settings)
5. Size: Headlamp portion is aprox. 5cm x 5cm x 2.5cm
6. Rechargeable batteries: Ni-MH or Lithium-Ion batteries (your choice)
7. Unbreakable: Great LED technology

Figure 1: LED Lamp on one of my friends helmets

2. Collecting Materials

1. 4 x Luxeon Star 1W Cyan (LXHL-ME1D or LXHL-ME1C) OR Green (LXHL-MM1C or LXHL-MM1D) - (the circuit will work just fine with any color LED you want)
2. Old CPU heatsink (around 5cm x 5cm x 1.5cm)
3. LED Dynamics Buckpuck (3021-D-I-1000 or 3021-D-E-1000)
   
4. LED Dynamics Buckpuck (3021-D-I-1000 or 3021-D-E-1000)
5. 4 x L2Optics/Dialight OP-015 lens
6. 4 x L2Optics/Dialight OH-ES1-CL lens holder
7. 8-10 x AA NiMH rechargeables, or 3 x Lithium-ION rechargeables
8. 2 small toggle switches (digikey 519PB)
9. 1 large toggle switch (digikey 514PB)
10. Flexible stranded wire
11. Sheath for wire (eg: sheath of a 3/16" double-braid rope)
12. Silicone or epoxy
13. Thermal compound (also known as thermal grease or heatsink compound)
    
14. Plastic or fiberglass for heatsink mount
15. Old headlamp headband

Figure 2: Ingredients

3. Solder the LEDs together

Start by soldering the Power LEDs together so that they fit on the heatsink. The LEDs are in a series-parallel configuration (see below). This means 2 LEDs in series, 2 pairs of that are in parallel)

Note: If you want to make a white headlamp (or any other color for that matter), the project will work exactly the same.

Figure 3: Power LED Circuit (Note polarities)

4. Apply heatsink goop

Next, firstly clean the heatsink thoroughly so that glue will stick to it later.

Then apply the heatsink goop (hightech name is heatsink compound a.k.a.thermal compound a.k.a. thermal grease) to the bottom of LEDs. They will probably have aluminum underneath. You can also use thermal "glue " instead, but it is hard to find and a bit pricey.

Stick LEDs onto the heatsink and wiggle them a bit (but remember to keep the goop from getting all over the heatsink since you will need to have the glue stick later).

Figure 4: The thermal compound (or Goop)

5. Glue on the LEDs

The glue is all I used to hold down my LEDs. It seems sufficient enough and is quite tough and durable to me. However, if you are worried, the alternative is to drill 2 holes for each of the LEDs into the heatsink (matching the cutouts in the star), and bolt them down with 4-40 size (or 3mm size) nylon machine screws. These are available from www.mcmaster.com.

Tips:

1. Do not get any glue on the LED lens! Some glues (like silicone) you can get off the lens after it dries, but uthers are to hard.
2. Make sure the glue can handle 80-100 degrees celcius. The LEDs get pretty hot. (Don't use hot-melt glue!). Also, make sure it is waterproof (don't use superglue)
3. I used silicone as a glue, but if I do it again, I will definitely try epoxy instead. The silicone does not flow by itself and this makes it hard to get it to fully cover the LEDs (in order to have a submersible waterproof lamp). With epoxy you can dispense it with a syringe and so accurately get it everywhere but the lens. Smearing the silicone around was a messy job!
4. After applying the glue, press the lenses and their LEDs in place.
5. Remember to test the LEDs again before the glue is hard.
   

Figure 5: The glued setup

6. Attach the buttons to the Buckpuck

Again hot-glue or silicone works. The big switch I used for the master on-off switch. The smaller ones will control the brightness of the LEDs. You actually need only TWO small switches (three was a bit too much turned out to be overkill).

Figure 6: The glued buckpuck buttons

7. Solder on the "brightness" resistors

Refer to the photo below. We will be building it by using "point to point" wiring/soldering.
Resistor values (and colors)

• R1 = 680 ohm (blue gray brown)
• R2 = 1200 ohm (brown red red)

The above values worked for my buckpuck (despite a somewhat misleading note in the datasheet). I encourage you to test your resistor values before soldering.

These resistor combenations give you FOUR overall power settings:

1. both switches off: full power
2. one switch on: 1/2 power
3. other switch on: 1/4 power
4. both switches on: 1/8 power

Soldering notes: These particular switches are made from fairly crappy plastic so make sure you solder them quickly. If you heat them too much for a long time they will melt inside and not work properly anymore. Follow these steps to solder them without overheating them:

1. Heat the resistor's lead and melt a small blob of solder onto it (called "tinning" it)
2. Heat the switch lead and do the same
   
3. Hold the switch lead against the resistor lead and melt the two solder blobs together, without needing to add any new solder.

This is good soldering practice. In general, you should follow this technique anytime you are soldering something together that is heat sensitive (such as the battery holders).

Figure 7: The resistors thet control brightness

8. Assemble the headlamp

And now the fun part, assembly. For this you will need an old headlamp strap and mount (or you could make one yourself from plastic and a bungee-strap). You'll have to figure out the best way to attach your heatsink to your headlamp, since it depends on your component choice. For my lamp, I cut two simple pieces of plastic to make everything fit (see below).

Figure 8: Assembly of the heatsink and lamp strap

9. Do the wiring

First, I covered the entire wiring (from LEDs to batteries) with a sheath from a 3/16" rope. If you've used very durable wire this step is not for you.

Next, I made a so called "strain relief" where the wires are attached to the headlamp. This is to prevent the wire from getting tangled or ripped when the battery is dropped, or the lamp angle is changed.

Make an normal overhand knot in the wire. Now glue it to the base plate like in the photo. The knot gives better grip to the wire sheath and the glue.

Figure 9: I used a LOT of glue

10. Make the battery pack

The "Buckpuck" I used lets you use pretty much any battery pack. The buckpuck is just an very efficient (90-95%) DC-to-DC step-down converter that ensures an correct outputs (voltage and current) to the LEDs, no matter what the input voltage is. The power LEDs may need up to about 7V to run them, and you'll need to add 2V more for the Buckpuck. This means any battery pack above 9V will work. I used 8 x NiMH cells that give 9.6V. Other combenations include 3 x lithium-ion cells (11.1V) and 10 x NiMH cells (12.0V). All good choices.

I used AA size batteries. These are 2700mAh cells, which yielded an output of about 3 hours runtime at maximum power, and 24 hours runtime at minimum (1/8) power.

Figure 10: Nice and neat

11. Finish the wiring and test!

Fix the final wires to the buckpuck.

Figure 11: Final step, wires

The lenses just press-fit into the lens holders. Several different lenses are available for these standard mounts, so you can choose the angles you want.

Figure 12: If you think this looks good, wait till you switch it on!

Don't stare directly into the light! It will blind you!



Listed under leds

An Ounce of History of the Wind Turbine

There are several different variations of the windmill, those made specifically for pumping water, those made for decoration and those made for generating electricity. There are two distinct categories of windmills, or as I will call them, Wind Turbines. Generally, the wind generators used for electricity production are Horizontal Axis Wind Turbines - HAWTs. The most common, are the large 3 blade turbine towers (see below). The other category is the Vertical Axis Wind Turbine or VAWT. These turbines derive their names from the direction in which their axis is mounted, i.e. horizontal or vertical.

Figure 1 : 3 Blade HAWT


Figure 2 : 3 Blade VAWT

Another big characteristic of these two turbines causes a considerable difference in their efficiency. The “blades” which catch the wind can either be lift or drag devices. A lift blade (mostly used on HAWTs) uses the same principal as an airplane wing or airfoil to “lift” or turn the blade. On the other hand, a drag blade (like those used in a conventional windmill) only gets pushed by the wind, which makes it the less efficient of the two when it comes to catching the wind.

Figure 3 : Lift device

The VAWT is the older one of the two turbine technologies and has its origins way back to about 500BC. You may find many patents on this type of rotor, it is the most often re-patented design. Apparently this design is still illusive enough to slip through the patent office again and again. The Savonius variation in particular is about 100 years old.

Figure 4 : VAWT; Darrieus, Savonius and H-Rotor respectively

In both the Savonius Wind Turbine and Pringles Wind Turbine DIY projects, I focus on the Savonius turbine (a VAWT) that stands on the ground and can accept wind from any direction. Both are drag devices, with lower efficiencies than the lift ones, but they are considerably easier to build.

Savonius Wind Turbine - 1kW

This page contains the plans for building a wind power generator in the form of a Savonius Rotor Windmill. Although this DIY project uses the same technology as my Pringles Wind Turbine, it is little more difficult to build. No welding or casting is required, however welding is recommended for one part.

This machine is able to produce 1000 Watts of power in an average wind speed of 20MPH. Depending on the builder, your results may vary.

This document is intended to share the process I used for building a wind power generating windmill. Specifically, a Savonius rotor. Enjoy.

Figure 1: The finished turbine


To be continued...

Pringles Wind Turbine - Pleech

The Pringles Wind Turbine (a.k.a. Power Leech or Pleech) is an attempt to turn simple items one can find at almost any hardware store (and elsewhere) into a fully functioning low-voltage power supply or generator. The Pleech was designed to convert wind or other air currents (such as from A/C ducts, dryer vents, etc.) into usable energy, in the form of electrical energy, using copper coils and magnets.

Figure 1 : The Pleech

1. Collecting Materials

You will require:

1. 1 Pringles Can (its not really a can per se)
2. 2 CDs
3. 1 Preferably metal, paper towel holder (like those used in a kitchen)
4. 12 Aluminum bobbins (not steel)
5. Copper Magnet Wire (lots, the thinner the better -- try out 36 gauge)
6. 8 Strong magnets (rare earth preferred, search for NdFeB on Google)
7. A wine bottle's cork
8. Some glue (I used a glue gun)
9. 6 Schottky diodes (again look for 1N5822)
10. 1 Large capacitor (preferably a super cap)
11. Some external wire, any
12. Some solder

Figure 2 : Remember to empty the Pringles holder, yum

2. Cut the Pringles Can in 2

Firstly, you'll need to cut the Pringles can into two halves, lengthwise. Be sure to mark it carefully with a pen and ruler. Uneven halves will create an unbalanced turbine that wobbles. A metal cutting tool helps; its easier than scissors and less ragged than a saw.

Figure 3 : Two equally cut halves

3. Mark out the CDs

In order to make sure all the different components of the turbine get put into the right place (especially for balance), it helps to write guides onto the CDs with a permanent pen.

If you decide to mark you own guides (I did, below), I found that the transparent "CD", that comes with some CD-R spindles, was helpful to use as the template.

Figure 4 : Marked CD

4. Fit the cork into the CDs

The wine cork is used to form the very simple axle of the turbine. I prefer the cork over the dowel I used in my first version because:
a) You can make them as close-fitting or snug as you need to, and
b) You don't compromise the turbine's efficiency by running a dowel pin through the center of it (which agrees with some of my research that it knocks down efficiency by something like 8%)

You can use a normal wine bottle's cork and cut it in half, then form the pieces over with a saw and sandpaper. Do this until they fit just right into the CDs' holes.

Be sure not to over cut them though. Cutting away the outside of the cork is a great time saver , but don't over do it. Better too tight than too loose. When you think you're close to the right diameter for the cork pieces, test and sand and test again.

Once the corks are the correct size, pierce them with small nails. These will form a sot of "needle bearing" on which the entire design will spin. Try hard to get the nails to be perpendicular to the CD and as close as possible to the center of it. Otherwise, the whole thing will wobble.

Figure 5 : Fitted cork

5. Attach the magnets

Now you need to attach the magnets (tape, epoxy, glue, whatever works) to the CDs so that they are equally spaced. Remember that the poles should alternate. A magnet that faces north is followed by one facing south which in turn is followed by one facing north, etc. Check the photo if you're confused. Marking the poles with a permanent pen also really helps.

Figure 6 : Magnets on CD

6. Glue the CDs to the can

Now you can glue the CDs to the top and base of the can halves. Make sure each half remains vertical; use a ruler if you need to. You want the generator to be as upright as possible. It's not difficult to do, but it requires a little patience and a lot of hot glue.

Also, try to follow the examples in the photos. The Savonius turbine requires that the two can halves over lap a little. This makes the air "push" on both "buckets" at once. Clever, huh?

Figure 7 : Glued on and overlaps a little

7. Paper towel holder preparation

This is the opposite half of the "needle bearing" I wrote about before. You'll need to make this deep enough so that the generator stays in place, but not too deep or too narrow that friction becomes a major problem. Some suggestions:

1. With a hammer, tap each end with a small blunt nail followed by a Phillips head screwdriver.
2. Just make a deep dent, not a hole.
3. Test the mechanical action frequently (with your turbine)
4. Adjust the height of the nails if there's not enough (or too much) pressure on the generator (i.e. it keeps falling out or it's stuck and really slow)
   

Once satisfied, glue down the corks to the CD.

Figure 8 : Paper towel holder with dimples in

8. Wind the copper coils

This part is crucial. The amount of power you generate pretty much depends on two things: (1) The speed of the wind, and (2) number of coils. Other factors also play a role, but these are the big ones. You have no control over the wind though, so make this step count. I highly recommend using thinner gauge wire than I did. I used 28, and got decent results, but I think 36 gauge will blow the doors off of my current set up. It's all about the number of wraps. The 36 gauge stuff is harder to find, so you can make do with thicker stuff (just be aware of the cost of doing so).

Here's how to go about it.
- use a dowel for the big spool of wire
- put bobbin on an awl, then insert the awl into variable speed drill
- leave 10 - 15 cm hanging when you start. You'll need these to make connections later.
- wind the first wrap slowly or by hand. If you're using thin stuff, do it by hand.
- you can increase speed thereafter. Again, be gentle if you have the thin wire.
- go back and forth, try not to cross, be neat.
- if using thin wire, be careful:

• in case of breakage, use a lighter to burn off the enamel that insulates the wire
• tie the pieces back together tightly
• it doesn't hurt to check the repaired connection with multimeter

- once finished, tape down the coil.
- leave 10 - 15 cm on the outside, too
- burn off about 1 - 2 cm worth of the enamel and the end of each coil with a lighter (just be careful with thin stuff, since it will burn up really quickly--a quick pass with the flame should suffice). Use fine sandpaper to take off anything that stays on.

Figure 9 : Do the winding with a drill to speed things up

9. Label the coils

I know, this seems kind of dumb to get its own step, but it's reaaaaalllllly important. The next few steps evolve into tangles and chaos pretty quickly, so it pays to be organized here. You're going to make three groups of four: A (red), B (blue), and C (green). Using Avery circle labels can help a lot. I found the combo of letters and color made life easier.

P.S. (ignore the odd ordering of the "B" group in the photo. Just number them B1 through B4. I had the order the way you see it there because of a different--and less efficient--wiring method I had tried earlier. More on that later).

Figure 10 : If you don't do this you'll forget which is which!

10. Solder the coils together

Here are some useful tips:
- solder flux helps a lot. You can use a lot less solder and with a lot less hassle.
- follow the diagram (bears repeating)
- do one group at a time. Start with A1 to A2, A2 to A3, A3 to A4, then go to the B group
- test the layout using the pattern provided.
- solder a thicker wire lead to the "1" end of each group. This will lead to the rectifier. More on that soon.

Figure 11 : Make sure this step is correct.

11. Make a base for the coils

I made my prototype out of foam core, but this will depend a lot on the size of your coils, the size of your magnets and the shape of the frame. Plus, if you're planning on keeping this outside instead of hooked up to an AC vent of whatever, keep weather proofing in mind (and while you're at it, give the Pringles can a good going over with Scotch Gard--I haven't tried it, but let me know what works for outdoor versions you make).

The most important thing is to try to get the coils to be as close to the magnets without collisions. If you can position the coils on the base so they sit just 1 mm below the spinning magnets (watch out for wobble) then you're in good shape. Also, try to make the base as stable as possible. At higher RPMs, the turbine can really start to rattle a bit, so keeping things together in those conditions is crucial.

Figure 12 : Excuse my handwriting

12. Layout of the coils

Once again, follow the picture. This is by far the most confusing part, and I think the picture should really help. Lay down one group (e.g. "A"), then another, then another.

Check that the current all flows one way. That is, if you imagine an electron running through the coils, it always enters the coil from one particular side and exits from another. Just don't cross the wires over, and you should be fine.

Now glue those coils down. Glue 'em down good.

Once that's set, solder the remaining three ends together (the ones not soldered to thick wire that should be sticking out of the "4" coils). This is the neutral point. In our circuit, you won't need to access this junction again, so you can tape it down or otherwise hide it under the coils' base, along with excess lengths of the other connections. In fact, the more you can do to tidy up stray wires, the better. A malfunctioning turbine that comes out of its divots has a nasty tendency to grab exposed wire and tear it up. Fun to watch, but hell to repair.

What you should have left are the three thicker wires connected to the "1" coils on each of the groups. This will lead into the AC to DC conversion circuit.

Figure 13 : All wired up

13. A brief explanation

Okay, so I haven't really gone over much in the way of what has been wired up here. What you have now is a Y circuit for a 3-phase alternating current generator. Instead of how we usually think of AC, like one big sine wave, this contraption has three waves working at three different phases at the same time.

The benefit of doing it this way is that we can jam in some more coils than we would if we just did a simpler version that produced a simple AC wave. Also, this method allows us to get about 1.7 times more voltage out of the generator than the coil groups would produce on their own. That's the magic of this "Y" configuration: it gets us more voltage for low RPM generators, which is definitely what we have here.

There is another configuration worth mentioning (and it's the reason my "B" looked out of order in the photos). The "Delta" configuration gives us the same voltage as the individual coil groups but about 1.7 times the current. So, if you really needed more current, and you could get the turbine spinning fast enough to take care of your voltage needs, that might be the way to go. It wasn't for me, but feel free to research it for your own stuff and let me know how it works for you.

14. Circuitry

There is a diode rectifier circuit shown below. This should make a nice, neat converter for AC to DC that you can tuck away wherever you need to.

That being said, start with a solderless bread board.

Either way, the big schottky diodes will need headers or wire soldered to them to fit in. They have leads that are too wide to go in. Regular diodes will fit fine, but they have a higher voltage drop. If you use the diodes I mentioned in the parts list, you lose less voltage with these big guys. Since every volt counts here, I'd highly recommend you deal with the added trouble of the oversize diodes.

When you put the circuit together, follow the rectifier diagram, watching the diode bands and capacitor polarity. Switching things the wrong way will make the circuit not work (or worse.) Attach a multimeter to leads off both ends of the cap and be ready to watch the voltage (start in millivolts for a reading, then work up as you spin it faster).

Attach coil leads by color per the diagram--they go between two diodes. The template should make this pretty clear.

Figure 14 : Circuits

15. Time for the test!

No time like the present. Blow on it, put it in the wind, attach magnets to the vertical piece of the frame and tack it up on a AC vent, hit with a Shop Vac blower (I've done this--it holds up just fine).

Some tips:
*apply more WD-40 if needed (note: a helpful commenter let me know that WD-40 is not a lubricant, but a solvent that has similar properties--until it dries up. Use light weight oil instead, 5 to 10 weight)
*blowing on it will get you about .5 V DC with my set up. Hopefully you will get a lot more (it's those thin wire wraps that will do it for you)
*I had 1.12 volts with it sitting on a fairly gentle AC vent
*with the Shop Vac, it gets up to 6 V at least before it starts to rattle like crazy and pop out of the dimples. You will probably get even better results.

Figure 15 : Success, it works!

16. Conclusion

That's it! You have a crazy renewable energy source of perhaps dubious usefulness. BUT there is a lot more that can be done. I'd like to throw out a few suggestions to the crowd for thing to try:

• double up the magnets and coils. Put one set on the bottom and one on the top. Wire the DC output of each in serial and double the voltage. Hopefully.
• bigger, badder coils. Really see if you can up those wraps to a crazy degree. I think that's the key.
• try a different bearing. My big thing is to use as simple and readily available parts as I possibly could, so I swore off fancier parts. You have no such limitation. I have it on good authority that skateboard bearings would be great for this. Or some other kind of bushing. Let me know what you come up with (especially if it's hacky, cheap, and better than what I've done.)
• Small lazy susans are available at art and sculpture supply stores that might also make good bearings.
• Made a bunch of these turbines? What happens when you wire them together in series? Can you make a "Pleech" farm?
• There's another more efficient Vertical Axis Wind Turbine design called the Darrieus Turbine (http://en.wikipedia.org/wiki/Darrieus_wind_turbine). It uses lift instead of drag. If you have an easy way to modify this turbine into one of those, drop a comment down here.

What I'd really love is for this to be the first (well, second) version in a long series of continually improving small turbines, the goal of which would be to power small devices (phones, sensors, art projects installed on public buildings, etc.) So, what did I do wrong? And what could be done a whole lot better? If you have answers, let me know. Hopefully, we can "crowd source" a way to make a pretty decent, and fairly cheap, wind powered generator.