Relatively cheap and pretty darn easy-to-assemble step lights made out of LEDs.
Glue gun and glue sticks
Soldering gun and solder
Felt or Thick fabric that matched the carpet on my existing steps
5mm UltraBright LEDs, color: Pure White with clear lens (3 per step light)
9v Battery (1 per step light)
9v Battery 'snap on' terminal leads (1 per step light)
Sub-mini Slide Switch (1 per step light)
Step 1: Soldering the LEDs
I chose to use 3, 5mm LEDs and 1, 9v battery so that I wouldn't have to worry about any math involving resistors. Please note that you may have to get into the math end of LEDs and their resistors if you choose to use a different combo. This was my first LED project, I wanted to keep it relatively simple.
If you're like me, you might find yourself wanting to 'play around' with the little LEDs. Try to avoid 'testing' the LEDs until they are soldered together, and then only touch the leads from the battery to the end of at least two LEDs soldered together. 'Testing' one LED can cause it to burn out from being overloaded. While you are able to light 2 LEDs as opposed to 3 with the 9v, I found the amount of light they gave off to be a little too bright for what I was going for.
To start off the step light:
I wired the LEDs in a series. This meant soldering the positive end of one LED to the negative end of the next led, then soldering the positive end of the second LED to the negative end of the third LED.
If you're not sure which little leg is the positive or the negative, don't worry. If you look closely at the two little, metal tips inside of the LED you'll see that one is larger. You want the leg coming out of the larger metal tip to be soldered to the leg of the next LED which leads up to the smaller metal tip. Once you have three LEDs soldered in a row, set it aside.
Step 2: Adding the 9v and Soldering the Switch
You want to avoid soldering anything DIRECTLY to a battery terminal. I found these snap-on battery leads online at a pretty low cost (see in picture). The leads come pre-stripped at the ends which make them pretty easy for soldering.
And now for the easiest step:
Attach the snap-on battery leads to the battery. :)
Once you've done this, feel free to 'test' away on those LEDs that you've already soldered. Simply hold one end to each end of the series of LEDs - you won't get shocked. This is also a fun way to figure out which end is your positive and which is your negative (the LEDs will only light up one of two ways). Try to keep track of which is which - you'll need to know which is the 'good' way once you start soldering on the battery and the switch.
Now for the sub-mini slide switch:
Despite being expensive as far as LEDs; I found that Radio Shack wasn't too bad so far as sub-mini switches go. There are a few other places online where you can look - up to you. I chose to go with a sub-mini slide switch that had two lead terminals (in the other picture) as opposed to three*.
*There's nothing wrong with having three leads. Just make sure when you're soldering that you're using either the 'first two' or 'last two' leads.
Now - go ahead and solder the tip of the red wire (coming out of the battery) to one of the leads. Then take the far end of the three, soldered LEDs (the end that made the LED's light up when the other end was touching the black wire) and solder it to the other lead of the switch.
Once this is done - you can go ahead and hold the other, unsoldered end of the three LEDs to the black lead from the battery and 'test' your switch. If you find that the LEDs don't light up - go ahead and double-check that you have them on there the right way. If you don't, no worries. Simply snip the end of the LEDs soldered onto the switch, flip them around, and resolder them starting with the other end.
If your LEDs are staying on no matter if you have the switch up or down, check to make sure that you didn't accidentally solder the two terminals of the switch together. Also, keeping a finger on both of the terminals at the same time causes a 'bridge' and may also be causing the LEDs to stay lit.
Step 3: Completing the Circuit and Not Burning Yourself With Hot Glue
Complete the Circuit:
Go ahead and solder the other end of the LED series to the tip of the black wire (you can keep the battery attached, no worries). You've now 'completed the circuit' and have made yourself a nifty, little light that you can switch on and off.
Tidying up the light, AKA Not burning youself with hot glue:
To avoid snags (and having to resolder the light every other day) I decided to 'secure' the switch to the battery. I did this by hot glueing one side of the switch to the 'top' of the battery, on top of the snap-on terminal leads. It should take a little bead of hot glue - apply pressure for about ten seconds while the glue is hardening. I also tried to position the switch so that the switch itself was in the down position (while on) to avoid accidentally bumping into the switch and turning the lights off as people walked on the stairs.
There should be just enough 'slack' so that you can glue the switch to the top of the battery and have your lights 'stretch out,' or 'flatten' leading away from the battery. If not, simply bend the leg of the last LED in towards the battery (avoid having the leg touch any of the other LED legs - you can also wrap it in a little piece of electrical tape if you can't avoid this).
Step 4: 'Hiding' the Step Light... and Not Burning Yourself With Hot Glue (cont.)
Please note that the next two steps are simply what I landed upon for myself in regards to the attachment and 'look' of the finished lights. I had also considered drilling a hole into the step itself and affixing the switch and battery inside of each rise of the staircase. While the set-up described so far won't lend to there being enough slack for this method - you can easily lengthen the leads from the battery and switch with some small lengths of electrical wire (if you have some old speaker wire lying around, that could also work). There's also nothing wrong with feeding your LEDs through plastic tubing - one of the great things about LEDs is that they give off a very low amount of heat.
'Hiding' the Step Light:
For this part I chose a semi-thick felt fabric that matched the carpeting on my stairs. I cut the felt into a strip that would be long enough to go over the step light and then cut little holes for the LEDs and the switch to fit through (see picture).
Not Burning Yourself With Hot Glue (cont.):
I then attached the step light underneath the little 'lip' on the front part of the step using the hot glue gun (please use caution - hot glue can turn on you like the sandbox in the Devil's playground). At this point, you can choose to use an extra, little piece of that same felt fabric (and hot glue) to 'hide' the top of the battery. Go ahead and 'focus' each LED onto the stairs - they can handle a little nudge here and there. You may also choose (if your lights are a little bright for your liking) to simply add a thin strip of the felt running on top (but not completely covering) the lights.
And you're done!
Now you can turn on your lights whenever you like and add a touch of safety to your steps.