Simple Water Detection Circuit

As part of a project to make DIY water activated diving flashing marker, I needed a simple circuit to detect when the marker is in contact with water. Turns all all it takes to do that is a a couple of basic components. Here is the diagram; P1 and P2 are the probes that will be in contact with water: Water detection circuit The LED (and its current limiting resistor) can be replaced with a buzzer circuit, a micro-controller, or another "smart" component to notify you of the water presence. For my purposes…continue reading →