This is the circuit diagram of Rain and Water Alarm circuit. This circuit generates alarm sound when its sensor is witted by water which make a short circuit (connection) between X and Y. A tone of about 1kHz which can be hear while detecting water, is provided by a stable multivariate from timer IC 555.
The sensor when witted by water completes the circuit and causes the 555 oscillate at about 1kHz. It has to placed generating an angle of about 30 – 45 degrees to the ground. This tends to make the rain water to flow over it towards the ground and prevents the alarm from going on because of the stored water on top of the sensor.
The metal implemented for making the sensor is required to be aluminum and not copper. This is simply because copper forms a blue oxide on its layer on prolonged exposure to moisture and needs to be cleaned on a regular basis.The aluminum foils may be secured to the wooden / plastic board via epoxy adhesive or small screws. The connection between X and Y from the sensor may be obtained by small crocodile clips or you could possibly use screws.
Build a Rain and Water Alarm Circuit Diagram
