Allow me again to describe and post one of my DIY which I have done.
Ok ..so let start ...
First things is to gather all of the material needed ..you can easily find this part in local electronic component store or from your back yard (the place you use to place the old crappy thing) For me I choose this since I have a lot of junkies laying around :)
Following to this scheme (all contribute goes to the dude who has this and share this on the net)
part list of the component :
LM358 (the heart of this thing)
some resistor, capacitor and VR and also one Transistor as a main switch to drive the neon driver controller.
and as above none of above component I need to buy since I use the component from my junkies stock (lm 358 is easily to find in the audio circuit and even If you have old graphic card some times this chip is also there (in smd)
basicly this thing is convert the audio signal output (from power amp or sound output jack into variable Voltage output which later this will drive the DC NEON INVERTER
Step 1: neon inverter
(DC NEON DRIVER)
this thing is the one I need to buy..It cost me approx 3 buck if I converted my local currency to the US.... BUT if you have the old scanner that you are not use anymore this will be the great source to gather this part.....
or ... you can build it your self with follow the schematic bellow