In this tutorial we will be creating the RGB Mixer. This light has three potentiometers that allow us to mix the amount of reg, green, and blue to create a surprising amount of colors. The potentiometer is an important component that is used to create a variable resistance.

A potentiometer will usually have three wires coming out of it. One wire is where the power goes in, on the other wires the power will exit but it will be a fraction of it’s original amount depending on the rotation of the potentiometer. When you go out to buy a potentiometer, they will have a maximum resistance listed. The maximum resistance means that you can change the resistance value from 1 all the way to the max. For our purposes, we are going to use a 430 ohm potentiometer. This range will let us mix a decent amount of color but it is not ideal because we cant apply enough resistance to fully dim the bulb. For the purpose this project though, it will work. Finding a potentiometer in the 1.5k or 2k range would be ideal.

Supplies

• Four short lengths of wire, a very thin gauge is best.
• One common anode RGB led.
• Three small potentiometers somewhere between 400 and 2k ohms.

Equipment

• Soldering Iron
• Helping Hands
• Glue Gun
• Wire Cutters
• Awl
• Needle Nose Pliers
• Solder

Step 1

Lets start heating the soldering iron and glue gun while we prepare our supplies.

Next we want to open the case then remove the battery and led. Never work on a circuit when it is powered! Even when working with low voltages, you don’t want to accidentally fry the micro controller chip so it’s best to remove the battery. Removing the led requires bending the wires a little, don’t worry, it does not harm the led.

Lets put aside the batteries and back of the case… save the led for another project, we don’t need it now.

Step 2

Now we need to modify the case to run wires. We are going to punch four holes right at the nose, under where the led sits. Using the awl, carefully punch four holes in the case ensuring that the holes are not so close as to connect. Make sure that the holes are wide enough to fit the gauge of wire you have selected.

The RGB led power line is going to go straight into the power side of the light but the three ground lines will come onto the outside of the case so we can control the colors.

Let’s prepare the wire for the ground socket. Because the gauge of wire I have selected is a little thinner than the leg of an led, I have to crimp the end to ensure a good connection. Using the needle nose pliers I fold the tip of the wire back over itself.

Because it is very hard to get a good angle when inserting the ground wire, I use the needle nose pliers to grip the wire and guide it in. When the wire is secure in the ground socket, take the end and guide it through one of the holes we punctured.

Now the hard part. We have to manipulate the little led legs so that the three ground legs go out the three remaining holes while the power leg is inserted into the power socket. Bending the three ground wires away from the power wire and threading them first is my technique. When they are sitting correctly and the led is sitting in the correct position, I clip the extra length on the power wire and then bend it into place with the needle nose pliers.

This can be frustrating but the led is pretty robust so you can force it into place and there is very small risk of damaging it. When it’s in place you should inspect the wires to ensure that nothing is accidentally touching.

Now lets flip the case over and get ready to solder! Learning to use a soldering iron is outside the scope of this tutorial so I suggest you practice by getting a small led kit or something of the sort. The soldering we will do to our mod is not very difficult, but it should be done quickly and efficiently as not to damage the case or light. Prepare your wires by clipping the ends very small… our goal is to have very little exposed wire showing.

Using the helping hands set, we hold the light and wire in place in order to make our connections.

After all three connections have been made you are ready to roll. What we have just set up is the basis for many of the mods we will do here on the site. You are now ready to customize it!

Step 3

Lets prepare our potentiometers. Because we only need to measure the potentiometer from one direction, I have clipped off the third lead. Using a very little amount of hot glue, dab the bottom of the potentiometer and affix it to the back of the light. Placement of the potentiometers comes down to personal preference but I try and work with the design of the case. When all three potentiometers are held into place, we are ready to make the connections!

Step 4

Keep the wire cutters and wire stripper handy, we are going to need to trim the wire so that there is no slack. With the light back in the helping hands, solder the wire coming from the ground socket onto the power in on the potentiometers. All three potentiometers share the same input signal but they each provide their own unique output to the different colors.

After soldering the inputs together to the ground wire, solder the three led wires to the three potentiometers. You can select which wire goes to which potentiometer to change the order of the colors mixed.

Step 5

With everything connected all that’s left is to trim any excess and bend down and sharp parts.

Now it’s time to put the batteries back in and close the case.

If all your connections are successful you will have a working rgb mixer light!