🚀 go-pugleaf

I was wandering through Walgreen's drug the other day, and saw an
interesting Easter toy selling for a couple of bucks.  It's a
fuzzy chick that chirps when you hold it in the palm of your hand.
The woman behind the register was kind enough to demonstrate it for
me.  Touching two metal grommets on the bottom of the thing started
it chirping.

Since skin has a very high impedance (i.e. when you touch two
probes of a multimeter to your hand, you don't get a measurable
amount of resistance/load), it probably detects the very slight
difference between an infinite resistance/impedance, and the very high 
impedance of skin (warm, oily/sweaty skin works better than cold/dry
skin, fingertips work better than the palm of your hand, etc., etc.).

Shorting the contacts with metal like copper produces unpredictable
results (fast, irregular chirping, or no chirping at all) probably
due to it being sensitive to too much load.

I only have one of them right now (and it is already reserved as
a present), but when I get some more (hey, if you can get over
the embarrassment of buying SOME things at a drugstore, you can
buy ANYTHING :-), I'll sacrifice one to science and report on its
"guts".  It uses a standard watch battery and might be an interesting/
educational present for the little tykes.

Paul W. Schleck, KD3FU

pschleck@odin.unomaha.edu