My son wants to enter the 4th grade science fair and wants to do something with electronics. As with most science fairs, the primary point is to "solve a problem" or prove a theory. I have millions if ideas for him, but can't seem to settle on any particular one. He's limited to certain power sources. He can only use batteries totaling up to six volts. Nothing in the exhibit can be plugged in, even test equipment. I was going to let him use my oscilloscope to demonstrate how a transistor amplifies, until I read about the power restrictions. Does anybody have any ideas for a simple project that doesn't require a whole lot of explanation to a ten year old? He'll need to understand the basic theory himself, which I'm able to coach him on, and be able to answer teacher's questions about it. I also would like it to be somewhat impressive. For example, I don't want a project like "How does a resister work".
......... I just thought of an idea while typing this that may be intriguing. I'll still like to hear any opinions or ideas from others on different suggested projects. The thought I came up with would be a demonstration on skin resistance. Using maybe a transistor amplifier and/or oscillator, a person could press two fingers from the same hand on two metal contacts and demonstrate that through surface contact and/ or varying moisture on the skin can change the frequency of the oscillator. The oscillator can be heard in a speaker. I guess I'm talking about a biofeedback monitor of sorts.
Any ideas?
Thanks, Jeff