A blast from the past - Color Organ Project

Well I decided it was time to take a step back from my home automation project and start one that was purely for fun. Back in the 1970's when I was in high school and college I used to design and build color organs. I always enjoyed changing the design to see how responsive I could make them. My last design was a four channel model that incorporated an automatic gain control front end as well as active frequency filters using op-amps. I also used homemade opto-couplers using some LED's and a light activated SCR to drive the triac outputs. It was my best design and was pretty state of the art for the day. The display case was also my largest using six clear 25 watt bulbs I stained for each color channel which were mounted in a four foot by two foot box. When used it would light up the room in a dazzling display of colors.

I decided to get a little nostalgic and build a modern version. I was going to look for my circuit and update it when I ran into a company called Xkitz which sold one that was very close to my design with an updated output circuit to drive 12 volts using MOSFETS. I decided this was easier than bread boarding one. The kit was very well designed with a nice looking printed circuit board. Here is the finished kit:




I had planned on using super bright LED's from the beginning but decided in the end to use SMD3528 LED strips in the end. I created a star design pattern with some photocopies of the strip. I also decided to use an old DVD rack that I was no longer using for the housing. I played around with several layout designs and finalized how many of each color I would need for the pattern I had chosen. To simplify creating all the star patterns I used a simple light box to lay the strips down on index cards. This would allow me to create each star as a separate unit which would make soldering all the connections together much easier. I disassembled the case and using my table saw I cut a groove near the front edge for the plexiglass to slide into.






After a lot of soldering connecting all strips together for each star I was ready to glue them down in the DVD rack and then wire all the channels together. I mounted the electronics in the bottom and the control panel on the side of the case. I powered the unit with a laptop power supply purchased off Ebay. I went around to different stores using a small LED flashlight to find the best looking pattern from the drop ceiling lighting plexiglass I was going to use for the front. Here is the finished color organ with all the colors switched to the on position (576 LED's):












I uploaded a short video demonstration playing a few 30 second snippets of songs that show off the capabilities of this color organ.

http://youtu.be/KNX-gj2ac7g