A Cold Cathode Audio Visualizer


Finally, cold cathode lights can be used for much more than illuminating the inside of your computer or making your whip look like it can hover. [James] discovered if he varied the voltage going into the inverter, only a certain amount of the tube would light up. Give a hacker an interesting observation and enough time, and eventually he’ll come up with something really cool. In this case, it’s a cold cathode audio visualizer, powered by fluorescent tubes doing unexpected things.

The build details are a little scant, but we were able to coax an imgur album of [James]’ build. He’s using these 20″ CCFL lights with the stock digital inverters replaced with TDK CCFL inverters.

The digital control of this build is provided by an Arduino Mega and a custom shield. We’re guessing the graphic EQ is provided by an MSGEQ7 chip, and the inverters themselves are powered through the Mega’s PWM pins. It’s a lot like an IN-9 Nixie graphic EQ, only much, much bigger. [James] is planning a larger version of this build, dubbed the Mega speKtrum and we can’t wait to see that build along with a proper writeup.

18 thoughts on “A Cold Cathode Audio Visualizer

    1. I don’t think it does. I have one of these in a PC case i bought about 10 years ago. it came with a board that had a mic and a variable pot and does exactly this, still works perfectly to this day! Has an awesome Borg-green look to it.

    1. Hobby Lightsabers were built this way about a decade ago. They looked amazing, but you couldn’t hit anything with them without breaking the bulb, and they only ran for a minute or two.

    2. They are made exactly like this but use a dedicated high voltage power supply instead of an off the shelf CCFL driver. Most in fact go to 2000 volts instead of 1000.
      I need to find these TDK inverters…

  1. I have always wanted to do this, after I first found a CCFL that showed the ‘variable height plasma’ effect in a damaged monitor. Props to actually pulling it off!

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