Is It Raining Outside? Set Up a Water Sensor
IF YOU ARE IN A CAR IN THE RAIN, you can press a button or move a switch and the windshield wipers will turn on and wipe the rain off the windshield so that you can see where you are going. Some cars come complete with special electronic sensors that sense when it is raining and switch the wipers on automatically. This experiment shows you how to build a simple circuit and a water sensor that will illuminate an LED when water touches the probes.
Setting Up a Water Sensor ...