[dpeterson3]

First off, someone told me last year that IR, Ultrasonic, and radio sensors were illegal because they emit waves (first year for me, so I believed him). Secondly, I got a sensor book for Christmas and it had a schmatic similiar to this one.
Notes (This was the first time I used this program)

The transistor is a MPF102 FET
The loop antena is actuall just a plate or wire
The volt meter is an amp meter

The electroscope is designed to sense changes in the electric field around the object. If a robot got closer, the field would change, right?