Wastage of water is quite prominent in urban as well as rural areas and overflowing of water tanks is a major reason for that. The circuit described here starts [[wysiwyg_imageupload::]]ringing as soon as the water tank becomes full. Thus, by warning the user, the project avoids the need to check overflow and prevents wastage of water. To detect the overflow, this circuit uses LM324 a 14 pin quad-op amp IC. In this circuit, this IC is configured as a comparator which produces its output on the basis of resistance comparison.Read more to find out how the circuit is designed and how it works.