Simple-bug is built from a circuit I found on the net. It uses 2 NPN transistors and two CDS cells
as its brains.

Simple-bug uses two pager style motors purchased from Electronics Goldmine
and two button cell batteries from the Dollar Store (6 for a buck) in a homemade
battery holder

 

 

 

Front View

 

 

 

 

 

Right Side
the motors were glued to a piece of plastic to set the angle and then the battery holder was glued to that
the circuit was then glued to the front

 

 

 

 

 

 

Back

 

 

 

 

 

 

Bottom

 

 

 

 

 

Off Position
Notice the switch at the back bottom of the bot. This is a momentary contact switch probably
from a printer, when the bot is placed in its normal position the switch is on, when parked as
shown the switch is off.