In this Instructable, I'll be showing you how to make a cool RGB LED strip dimmer using a few potentiometers and a couple of 555 timers.
I'm currently working on a larger project which involves using this circuit, but I thought it would be good to share this circuit since it's really cool to play with just by itself. The larger project I'm working on is comprised of two circuits: the RGB dimmer and a colour organ which makes the LEDs dance to the music when an audio source is plugged into the circuit. I was inspired to work on this project after posting this Instructable here which used a single colour LED strip with a dimmer and an audio pulsing circuit. After posting this, I received many comments and messages requesting to work on an RGB version of the circuit, so here is part of it, with the rest to follow very shortly.
Since I am posting this Instructable while in the process of finishing off the other project, a few of the pictures I have included here actually show parts and components from my other project build. I can assure you all however that the parts I have listed in the following step are all that you need to complete this project and I explain later when you can ignore other components that appear in my pictures.
Anyhow, I hope you all enjoy this Instructable and I'll be posting the larger project very soon! See the attached video to see what you're going to make in this project, hope you like it!!
Step 1: Gather Your Parts and Materials
You'll need a few things for this build...
1 * NE556 Dual 555 timer linear IC
3 * TIP31 transistor
6 * 100nF capacitor
6 * 1N4148 diode
3 * 4.7k resistors
3 * 10k variable resistor https://www.jaycar.com.au/10k-ohm-linear-b-single... or http://core-electronics.com.au/rotary-potentiomete...
1 * variable resistor knob (red) https://www.jaycar.com.au/10k-ohm-linear-b-single... or http://core-electronics.com.au/black-plastic-knob-...
1 * variable resistor knob (green) https://www.jaycar.com.au/10k-ohm-linear-b-single... or http://core-electronics.com.au/black-plastic-knob-...=
1 * variable resistor knob (blue) https://www.jaycar.com.au/10k-ohm-linear-b-single... or http://core-electronics.com.au/black-plastic-knob-...
1 * RGB LED Strip of your chosen length. Here's what I bought (5m): http://www.ebay.com.au/itm/252554507922?_trksid=p... or http://core-electronics.com.au/led-rgb-strip-bare-...
1 * 12V 6A power supply to go with the LED Strip
Various sizes of JST connectors http://core-electronics.com.au/jst-connector-kit-2...
A bunch of wire
Bench top vice
Step 2: Prepare the Potentiometers
Solder three wires to each of the potentiometers and at the free end, add a 3 pin JST connector. I've colour coded mine: left pin black, middle pin white and right pin red. Solder them all up the same, since you want to be able to connect and disconnect to any output of the timer ICs.
Slip the coloured knobs on the ends of the pots and you're ready to start soldering the veroboard circuit.
Step 3: Solder Up the Veroboard
Take the provided circuit diagram and pin outs for the 555 and 556 timers and solder the veroboard. Remember to include three 3 pin JST connectors in your layout somewhere so you can easily plug and unplug the potentiometers.
You'll also need to include a 2 pin JST connector for the power input and a 4 pin JST connector for the LED strip. In the pictures you will notice I have a 3 pin JST at the top right of the board and a 2 pin JST on the top left of the board and some large diodes running down both sides. You won't need the diodes for this circuit and you only need a 2 pin connector for the power input. You also don't need the smaller diodes that run from the discharge pins of the 555/556 timers to the transistors. So just follow my circuit diagram which doesn't include these other components and you should be okay.
For the LED strip connector, the white wire which comes off the LED strip should be connected to 12 V, while the red, green and blue wires should be connected to the TIP31C transistors as shown in the diagram.
Step 4: Plug Everything In, Power Up and Test
Plug in your 3 potentiometers, the RGB LED strip and your 12 V power source. If everything is wired up correctly, you should be able to control the red, green and blue lines of the LED strip individually, making many different colours through different red, green and blue colour intensities!
Hope you guys liked this build and please follow me so you get to see the next stage to this circuit- adding a colour organ so the lights can also dance to the music!