A little off topic......

That time of year.....

Its the time of year that people keep coming up to me for ideas for science fair projects... even though they are due in a week or two. I would like to hear what you folks did for your science projects as kids...I built a one octive organ one year...still have it, was right when transistors were brand new things.
This year I have come across a bunch of 24vdc photo switches...seperate emitters and recevers...my next question is can I inject an audio signal on the emitter supply to modulate it and use the reciever to drive a speaker without a whole lot of extra parts?
Alright now, lets hear all of your great project ideas.....David

Well, my third grade science project was to have my dad come in with a block of dry ice and watch my classmates cover their ears and cringe as he ran a metal fork around on it.

I think my best science project was a qualitative study of what materials an infrared beam could and could not travel through.

And don't forget everyone's favorite, the simple generator connected to a light bulb.