Simple Water Sensor
This project is a a very simple water-leak detector.
Place two exposed wires on the floor near your washing machine or some other place where you want to detect leaks. As long as everything is dry, nothing happens. When water reaches the two wires, it conducts just enough electricity to switch a transistor on which turns on an LED.
The Circuit
When the two sensor wires are dry, almost no current flows into the transistor, so it stays off and the LED remains dark.
When water bridges the wires, a small current flows through R1 into the base of the transistor. This turns the transistor on, allowing current to flow through the LED and its series resistor (R2). The LED lights up, showing that water is present and the circuit is responding.
Parts List
How To Build
This is a simple circuit that's perfect for soldering onto a stripboard.
