Light Bar Ambient Lighting





Introduction: Light Bar Ambient Lighting

Let It Glow!

Third Prize in the
Let It Glow!

A light bar can brighten your house through the use of ambient lighting. You can lighten up hallways, add a fading glow effect behind your entertainment center, create new patterns in light graffiti or simply add a light source to your house. There are endless possibilities for lighting with a light bar, it's all up to you!

The parts are fairly cheap and the project is fairly easy. You will need to strip wires, solder leds, and be able to use a power drill. With LEDs cheap and long-lasting this project will add a warm glow to your house.

Once you have purchased the parts you need (You likely have most of them already) actually putting the bar together should take about 3 hours (if you are inexperienced).

This instructable is designed to teach with pictures as well as words. Most of the pictures have notes added to them with tips and information.

*** I am not liable for any injury, property damage, or any other losses that happen within this project. You will be working with electricity and should be careful. Though the voltage and amperages I used in this project are not harmful (or even be felt), using a more powerful electricity source, and the use of hot objects (Soldering Iron & Hot Glue Gun) can cause damage. ***

Step 1: Parts & Tools

The pieces needed for a LED bar are reasonably cheap. Don't be alarmed at the amount of parts needed - nothing is expensive, all of them are pretty common and easy to use. You probably already have 3/4ths of this stuff right now.

Most of these parts were purchased at The Home Depot and Lowes.

Metal Wire Cover (Light Bar) $5.00 for (1) 5' bar. Used to keep people from tripping over wires in the home or office, I modified it to become my light bar. You could also use wood, PVC pipe, or another material. (Though I suggest something compact and tidy).

Rubber Insulated Clamps (3) $1.25 for 2 - These are used to mount the light bar to a surface.

Electrical Tape (1) $4.00 for 66' - Used to hold pieces together and insulate wires from bar.

Wet Rag - Any cloth or sponge will do, just soak it in water, its used to clean leftover solder off your soldering iron.

LEDs (18 for one light bar) $10 for 100- Pick whatever colors you want. I also suggest fading LEDS. You can use any voltage you want, though most colors fall in two categories, 1.9-2.1v(red, orange,yellow), and 3.0-3.4v (green,blue,white). Brightness is up to you, 10000mcd-18000mcd (Millicandelas) are plenty for night lighting, something like 25,000mcd may be too bright for night time, but good for accent lighting (glowing under furnitur, though 35,000mcd or higher can even be daytime lighting. Real life stores are far too expensive, so on EBay you can get them from Hong Kong for 1/20th the price. I suggest the sellers HKJE LED or LED-HK

Hot Glue Gun $5 - Get a lot of glue sticks, as they will hold things in place and insulate.

Power Supply (1) $1- Any source of power will do, though LEDs run on DC. Your voltage can be whatever you want, but you must choose your own resistors. (Supply Voltage should be higher than the LEDs Forward Voltage, around 300mA for one light bar (Milliamps are the max amount of LEDs you can have). I got three supplies for $3 at my local GoodWill charity.

Resistors (At Least 10) $3 for 100 on EBay, I suggest ResistorsPlus- These keep the LED from taking in too much electricity. It can change a 9 volt or 12 volt power supply into a 3.3 volt for an LED. For my 9 volt supply, I needed 150 Ohm resistors (9 Volts for 2 LEDs in Series). Calculate yours @ A common rating is wattage, this simply means heat dissipation, you can always have the W number higher than recommended, but never lower. A higher wattage rating costs a tiny bit more, and is larger, for the most part 1/2 watt is fine, unless you begin using ultra-high power LEDs (like Luxeon Stars which can need 3-10W resistors). 

20 Gauge Speaker Wire (Around 8-10 feet) - Used to connect the LEDs to the power supply.

Soldering Iron $10 (1) - Cheap, everyone should have one around. A 15 Watt iron from Radioshack works fine.

Solder (1) $3 at Radioshack- Solder with flux. I recommend silver solder at 0.022" thickness and a rosin core, it's easier to flow and more durable. Used to connect LEDs to the Speaker Wire.

Needle-nose Pliers - Used to bend LED legs.

Insulated Quick Disconnects (Optional) $2 for 12- This is used to easily plug the power supply into the light bar. You could just solder the power supply wires straight to the speaker wire, but then you always have the cord attached. (***Update, I now recommend using 2.5mm DC barrel plug connectors, they are much more durable, easier to plug in, and make a stronger connection. Buying them online is semi-random, try eBay as always**

Power Drill (1) - If you don't have one, ask a friend.

13/64" Drill Bit (2) - $1.50 for one. Used to drill the holes in the light bar. 13/64th" is the perfect size for a 5mm LED, it keeps them from going through the hole and holds them in place.

Wire Clippers - Used to cut the legs of LEDs. You can use some small scissors as well.

Awl - Something sharp with a fine point. I'm sure you can find something.

Scissors - Used to cut speaker wire and electrical tape.

Wire Stripper or Knife - Used to strip plastic insulation from the speaker wire.

If you are new to LEDs or soldering, I suggest viewing this guide @

Step 2: Light Bar Material

What I used for my light bar is a metal wire cover. It is designed to stuff wires into to keep people from tripping over them and yanking everything out. I chose metal because I wanted something durable and all in one piece.

You don't have to use metal like I am, or even a wire cover. If you can find a piece of wood and drill holes through that, awesome! Plastic wire channels work even better, and are much easier to drill through. I chose this because it's cheap, I was unexperienced when I made this guide, and I wanted the bars rigid, today I suggest plastic channels, don't get the thin ones though.

For mine, it has a metal clip that is just smashed on top of the bar. Just push on it with some pliers to pop it out.

Step 3: Mark and Measure

Mark the LEDS

Light Bar = 5 feet = 60".
Take off 2" on each side for the Insulated Clamps and connectors = 56".
9 Modules of 2 LEDs each = 18 LEDs.
56/8= 7" of spacing. (We divide by 8 rather than 9 because 2" is the where the first module goes).

For a light bar 5 feet long, each module should be spaced 7 inches apart. Get a measuring tape or yard-stick and with a pencil mark these slots for a 5' light bar.


Now the LEDs should be spaced 1 inch apart. So at each of the previous marks, measure 1/2" on each side and make a plus with a pencil (Try to put it near the middle of the width of the bar). This is where each LED will go.

Measure the Length of the Speaker Wire.
This is fairly simple. Just stick your wire along the bar and measure out 8 or so extra inches. These 8 inches make up for any slack within the bar, and provide extra wire to connect to power supply. When you are finished, you'll just cut off the extra anyways.

Pull the two speaker wires apart from each other, we want them to be separate (see picture).

Step 4: Measure Twice, Drill Once

There are a couple ways you can go about putting the holes into the bar. You could just use the drill bit and inaccurately drill through the bar. However this takes far more work and is more tedious than it should be. This is where the awl comes in.

Remember the marks we made on the inside of the bar? Well, take your awl (or another sharp pointy tool) and put it on the line you drew for a LED. Try to line it up with the middle of the bar and smash the awl with a hammer. Initially you should make a dent and punch a very tiny hole, later you will punch a small hole back through.

Flip the bar over, and put the awl on the new dent pointing towards you, and smash it downward to leave a bigger dent (this is thanks to metal fatigue). Hit it until there is small hole (less than the width of an LED), and use your 13/64" drill bit to clean it up.

Repeat 18 times for 18 holes, and then we will prepare the wire.

Step 5: Power

Power Supply
Your power supply can be from pretty much anything. An old PSU from a computer, a leftover hard drive power brick; I prefer small and compact power supplies such as those in cordless phones. Laptop power supplies are an amazing power source, they are super cheap and available, usually can supply 3-5 amps (which means a max of about 230 LEDs), and are regulated [which are normally super expensive] at 12v DC. No matter what the plug on the end is, you can bet there are two wires in there: Positive and Negative.

I obtained three 9 volt power supplies at my local goodwill for $3. eBay also has a plentiful selection of power supplies, though it will take some searching. The supply needs 350mA or more to power 18 LEDs. mA determines the maximum amount of LEDs. 99% of 5mm LEDs use 20mA each, so just multiply the number of LEDs by 0.020A (18 LEDs * 0.020A = 360mA, which is technically overloading it, but it still works). 

The speaker wire will carry the electricity from the power supply wires to the LED wires. Decide right now which of your two speaker wires will be your positive, and which will be your negative.

As a general rule, the red, yellow, white, or lined wire is the positive, while the solid (usually black) is negative. After the next step, you will have two LEDs and a resistor soldered together. Just try touching them both to the speaker wire, whichever lights up for you is your correct solution.

Quick Disconnects
This step is optional. It makes it easy to plug and unplug the light bar from the power supply. If you don't want to use Quick Disconnects and want the power supply always attached, just twist the wires of the speaker wire and the power supply together and solder them. Wrap them with electrical tape to keep anything from shorting out.

Quick Disconnects have a wire going into them, and usually you just crush it with pliers (Called crimping) and the wire stays in place. An optional purchase to skip this awl & solder method is a pair of crimping pliers. Regular pliers were incapable of doing the job for me, so I pierced and soldered them into place. Knowing from experience now, I strongly recommend just buying crimping pliers than this next awl + solder method. If you don't feel like spending money, then go for this method, which actually is a stronger connection than crimping alone.

Because its not possible to stick solder into the Quick Disconnect (its covered in plastic) and melt it and the wire together, you should coat the end of your wire with solder. Stick the wire into the quick disconnect. Now hit the Awl on top of the Quick Disconnect, this will pierce the casing and squish the metal and wire together. Follow it up with sticking the tip of your soldering iron into the hole to melt the solder. You should have a very solid connection between the wire and Quick Disconnect. Finally, wrap any exposed areas up with electrical tape.

Step 6: Snip, Sheath, & Solder

LEDs like the ones we are using in this project have two legs. A positive long leg (and a skinny head), and a negative short leg (with a bulky head). The resistor attaches to the front positive leg (see picture) and the resistor is soldered to the positive speaker wire. The purpose of the resistor is to keep the LED from getting overloaded (they will without one, and become very hot and burn out permanently).

Use the pictures as a guide.

Soldering LEDs Together
Bend the legs of each LED to 90 degree angles. Clip the front positive leg so it is short , this is where the resistor will be attached. These are wired in a Series, meaning the LEDs legs meet back to back (postive-negative-positive). See the diagram for a visual illustration.

Set the LEDs into the drilled holes, as this keeps them aligned and pointing in the same direction. Make the legs meet, and touch the soldering iron at the meeting point. Touch your solder to the legs, and it should melt onto the legs binding them together. Now bend the front positive leg into a U shape, repeat for the resistor. This hooks them together and makes it easier to manage. Solder them together.

Soldering LEDs to Wires
After the resistor has been attached to the front positive LED, remove sheathing from the positive speaker wire, and solder the leftover resistor leg to it. Then remove sheathing from the negative speaker wire, and solder the negative LED leg to it. You can now test if your LEDs light up by plugging in your power supply.

Securing/Insulating with Hot Glue
Place the LEDs and the newly attached wires into the bar, and the LEDs go into the holes. Make sure that no LED legs or exposed wire is touching the bar. The LEDs and wire will naturally want to move around, so press the LEDs down with pliers so they are flush with the holes, pour on a lot of hot glue, and wait for it to dry.

Repeat this step 8 more times, and then its time to finish everything up.

Step 7: Finishing Up

Hopefully all your LEDs light up, your power supply has a solid connection to the speaker wires, and the hot glue is holding everything in place. Now its time to finish this light bar.

If everything is set on your light bar, snip off any extra cord handing out the back end. Wrap the end with electrical tape just to keep it together.

If you find yourself making a lot of these, a step I don't cover is called daisy chaining. Basically you put quick disconnects on both ends, so it can be powered on via either side. Then you make a short (3 inch or so) connector cable that plugs the light bars into each other end to end, this chain can go on indefinitely. If the quick disconnects on both sides of the light bar are female plugs, then your connector cable would have male plugs on both ends of it.

Put the slide back into the bar, closing up the light bar. Reinsert the friction clip to lock the slide in place. And the light bar should be completed. Now you can choose where you want to put the bar itself.

This is where the Rubber Insulated Clamps come in. I like to use screws, however nails are equally good. One clamp goes in the middle, and two on the ends. This is why we saved 2" on each end of the light bar, making it easy to attach to a surface. Pictures show how it can be done.

Optional Sanding
This is a step you can use to change the appearance of your LEDs. If you feel that your LEDs are too bright or shining too strong of focused beams, you can sand the tops of the LEDs to more evenly diffuse the light. Go purchase some very fine (600-1200grit) sandpaper and just rub the top of each LED. you should have a smooth blurred LED, and this will scatter the light more effectively.

Step 8: Mounting the Light Bar

Now that you've finished your light bar, there are numerous places to put it.

I've put some behind my couch so beams of green and blue lights shine out of the back. We also screw them into the ceiling to shine down the walls for our primary lighting in our house. For LAN parties (with the red and blue rooms of the house, each with red and blue LEDs) we place them in the corners to shine along the walls for each team's room color, and green LED light bars signify the neutral room with all the food and drinks. Use your imagination to place these bars, especially with the use of refractive (glass) or reflective surfaces.

This guide was focused on a 5 foot bar, but any size will work. If you have any improvements upon my methods, or great ideas on how to use a light bar, feel free to leave a comment.

Happy lighting - QuackMasterDan.



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    Is there a way to use many different colors and have some type of switch to turn each color on and off separately to create different combinations?

    I should also add on, that this guide is rather old. Recently there are now LED ribbons that do the exact same job (R-G-B-R-G-B) as my painstakingly made light-bars. A TON easier and cheaper, eBay is your best source. It's going to be a number and a RGB ribbon, I think the 5050s SMD/SMTs were the best model I found. Hope that helps!

    Indeed, it requires a micro-controller using pulse-width-modulation. It doesn't have to be as hard as it sounds.

    I previously was working on an Instructable for this exact project, but I got tired and never finished writing it for publication. There is enough in there to figure it out with some work, and it's a good start.

    It is located here:

    Okay so I have a quick question. How would you add a female and male audio jacks to this circuit so I can play music along with making the lights flash? Currently I have 100 LEDs and a 12V wall plug that has 1amp work of power since thats what I need to run the lights. Pleasepleaseplease help me.

    Correction 50 LEDs

    Definitely much harder. I have been working on it myself and to do it through a micro controller you need programming experience. And through analog you need schematic experience.

    It's actually much, much harder than you would think it is. You'll need to have a programmed microcontroller (Arduino is the most common for this), which can either a) react to a microphone and turn on/off power related to volume or frequency, or b) program the microcontroller to listen in on the raw audio-feed from your computer with a serial connection. It's a pain and it's expensive since you need equipment for programming and operating the chips. Wish I had better news =[

    I am not much into electronics but while going through the comments of your instructable u said that one can't connect more than 2 leds in series , then how do christmas chain leds work with a consistent glow though they are connected in series.. ? i hope u get me ..

    They are actually run in parallel.

    The entire build and install was completed today. Aside from gathering parts which took about two weeks of course (shipping from China is slow). Took about 200 pictures. I need to clean up the house and make everything pretty for photos in the guide though, but here is an idea of the result.