Low-Budget Electronics Projects For High School?

SciGuy writes "I am a physics teacher for 9th graders. I really want to teach them modern electronics (something beyond the light bulb and battery). My hope is for a project that: 1) Is fun 2) Teaches about circuits that are relevant to their life. 3) Doesn't rely too heavily on a black box microcontroller. Individual components would probably be better. (I realize that #2 and #3 are probably contradictory. They will already be programming in my class but I want them to understand the circuitry behind modern tech.) 4) It must be as cheap as possible. Yay, public school. Unless some of the parts can be scrounged or found at home, I would probably want to keep the project around $5." What would you build?

Comments

Re:555 Timer

[Bakkster]

The 555 timer is deader than dead. Might as well teach them how to use a vacuum tube, at least those are still used in some high-end audio amplifiers. The 555 died with the microcontroller, and will never come back.

A simple transistor circuit seems much better, as it would use modern technology, and is useful. An amplifier would be nice, and could be as simple as 1-2 transistors, a potentiometer, and some resistors. If the kids chip in $2-3 each they could get 1/8" audio plugs and play their iPod through it to speakers. As a bonus project, the kids could make their own paper-cone speakers.

http://en.wikipedia.org/wiki/Electronic_amplifier
http://www.ecircuitcenter.com/Circuits/pushpull/pushpull.htm