One of the things I'd like to add to my diorama is an arc welding simulation. Basically, white, blue and red LED's flashing at a rate to look like somebody is arc welding when viewed indirectly.
You can buy them ready to plug in and go for around $40 plus shipping. The really nice ones are run with an Arduino microprocessor and can even include sound, randomly variable arc times and a red "cool down" interval. I've spent some time dicking around with Arduino microprocessors. They're fun, but the programming can get pretty involved and in my experience the firmware doesn't always retain the program when turned off for long periods. Besides, where's the fun in "plug and play"?
Saw a very simple one on Ewe Toob made with a 555 Timer IC, a couple of resistors and an electrolytic capacitor. "Hmmmmmm" sez I, "I bet I could whip up something like that." I ordered up a sleeve of 555's (about $10) and a selection of electrolytic caps (another $10 or so) and started breadboarding.
First discovery is that a 555 running off 6v will only drive one LED. Not really an issue as I don't want them flashing at the same rate anyway. So I plugged two 555's into my breadboard, one running a blue LED, one running a white LED. I'm messing around with flash rates by trying different combinations of resistors and capacitors. (For anybody that's into electronics - varying the RC Time Constant) Found a calculator on line that lets me plug in values and poops out the on and off times.
Once I get that tweaked, I want to see if I can figure out how to work a third circuit to turn both white and blue off and a red one on for a few milliseconds.
Been quite a while since I fooled around with electrons, this is kinda fun!