back to electronics

I used to study quite a bit of electronics back at university. At some point, I assmebled a printed board with a microcontroller, 8052 or something like that. I knew voltages and so.

But I've been devoted to software for long time now, and I dont remember anything. I love the internet, so I found instructables.com and creationist.net, then I wanted to do electronics again.

These are my two next projects:

Build a laser burner:

http://www.youtube.com/watch?v=chC8fz-RxTs

build a Time Fountain (this one is _amazing_):

http://www.youtube.com/watch?v=rvY7NGncCgU

yesterday I was trying to make the laser. I have lots of electronic devices in my room, because everytime a broken electronic gadget comes to my hands, I 'deconstruct' it and keep the interesting parts (for fun) (motors, lasers, sensors, etc) so I had 3 spare lasers from an HP laser printer and a DVD burner.

so I went to ondaradio and bought a power supply (110 euros), asked for 1W laser but they dont sell lasers anymore. They dont have UV leds (for the time fountain).

at home, I burnt the 3 lasers. Advice: a laser needs a resistor, otherwise it burns.
Next DVD burner I get, I'll have my laser, with a resistor :)