How to Make LED Lights Flash to Music in a Car.

This Instructable will show you how to make a LED Controller that can be directly wired to a car sub woofer amplifier or standard speaker output. It is constructed entirely of recycled parts and may cost you nothing.

I chose to make this Instructable as I was unable to find a device similar to this available for purchase

A Video of it in action is attached as it takes too long to convert. You probably need Quicktime or VLC.

The controller uses a 12V SLA battery and a transistor to control when the lights should be active by monitoring the speaker output. It works best when wired to a subwoofer as it only activates the lights when a beat is present.

You will need:

A box to put it in (I used an old Pioneer home theater speaker)
A Heavy Duty Transistor( The transistor I used was a ST W14NC50 from an old Compaq power supply unit)
Wire
A soldering iron
A switch (optional)
3 Speaker input ports(don't know what their actually called)
A 12 Battery. (Make sure the voltage isn't to high over 12V as you may blow the LED's)

Step 1: Constructing and Soldering the Circuit

Construct and solder the circuit using the transistor you have sourced. It is best if the transistor is attached to a heatsink in order to prevent it from overheating and failing.

Step 2: Test the Circuit.

To test the circuit find a battery with a 12v charge. Connect it to the red and black wires. Connect the two orange or amplifier wires to a smaller battery such as a 3V computer battery. If all goes well the LED's will light up. If not, try reversing the polarity of the 12V LED strips or testing them with the battery itself.

Step 3: Making It Look Nice.

In order to make it look neater and to easily mount it within a car you should mount it within a box. I used an old speaker as it already had a port that could be used to wire the LED's into. Any small box should do though.

Step 4: Add Any Finishing Touches

To my LED controller I added some aluminum checker-plate and engraving to make it look more solid and personalised.

Step 5: Installing the Controller

To install the controller mount it to a suitable place in your car. I would not recommend connecting it directly to the car battery unless you add some sort of circuit that regulates the voltage as it will otherwise blow the LED's.

Connect the LED's to the controller.
Connect the two wires to the subwoofer or speaker amplifier, ensuring the channel they are connected to is active.

A Video of it in action is attached as it takes too long to convert. You probably need Quicktime or VLC.

Do not use this system while driving as it is likely you will get defected and have to uninstall it. Try to keep it off when on the road. I DO NOT ACCEPT ANY RESPONSIBILITY for any damages it causes you, be it damage to your car, damage to your lights, battery, etc.

It works well as a show-off piece with friends as it is difficult to purchase a similar system.

And that's it. I hope this tutorial was useful to you.