Here the circuit diagram of low cost water pump controller. The automatic pump controller minimizes the need for any manual switching of water pumps installed for the functionality of pumping water from a reservoir to an overhead tank . It instantly switches on the pump once the water level within the tank falls below a specific low level (L), provided the water level in the reservoir is above a specific level (R). Subsequently, because the water level in the tank increases to an upper level (M), the pump is turned off instantly. The pump is turned on again only if the water level once again falls beneath level L in the tank, provided the level inside the reservoir is above R. This automated action
continues.

The circuit is intended to “overlook” the transient oscillations of the water level that would otherwise trigger the logic to modify its state rapidly and unnecessarily. The circuit works by using a single CMOS chip (CD4001) for logic processing.

No utilization of any moving electromechanical elements within the water-level sensor has been made. This assures fast reaction, no wear and tear, and no mechanical problems. The circuit diagram can be seen on above image. The unit performed satisfactorily on a test run in conjunction with a 0.5 HP motor and pump.

The sensors applied to the circuit could be any two conducting probes, preferably resistant to electrolytic corrosion. For example, in the easiest case, a appropriately sealed audio jack could be utilized to operate as the sensor.

The circuit may also be utilized like a constant fluid level maintainer. For this objective, the probes M and L are brought pretty near to one another to make sure that the fluid level is maintained within the M and L levels.

The benefit of this system is that it could be applied to tanks/reservoirs of any volume whatsoever. Even so, the circuit can’t be applied for purely non-conducting fluids. For non-conducting fluids, some modifications have to be prepared in the fluidlevel sensors. The circuit can on the other hand be kept intact.