07-04-2012, 03:57 PM
RAIN SENSOR USING 555 IC
MINI PROJECT SYNOPSIS.doc (Size: 97 KB / Downloads: 196)
INTRODICTION:
This circuit gives out an alarm when its sensor is wetted by water.
A 555 astable multivibrator is used here which gives a tone of about 1 kHz upon detecting
Water.
The sensor when wetted by water completes the circuit and makes the 555 oscillate at
about 1 kHz.
The sensor is also shown in the circuit diagram.
It has to placed making an angle of about 30 - 45 degrees to the ground. This makes the
rain water to flow through it to the ground and prevents the alarm from going on due to
the stored water on the sensor.
APPLICATION:
The rain alarm apparatus is placed below the tank in such a way that water strikes the rain sensors as soon as the overflow occurs,now as we know that water is a good conductor of electricity,so the circuit gets completed by this overflowing water and the alarm rings,giving us an indication about the overflow.