In many homes and other public places, ground water is used, which is pumped up to overhead tanks using water pumps which are controlled by electric motors. Controlling the pumps is often a necessity to avoid wastage of water.

1. Contact Water Level Controller

Here a simple circuit to control the Water pumps. When the water level in the over head tank exceeds the required level, the pump automatically turns off and stops the pumping process thus preventing the over flow of water. It uses a relay to cut off the power supply to the water pump.

The circuit is build using the following components:

CMOS IC CD4001: It is a versatile 14 pin IC which contains 4 NOR gates. Each NOR gate has two inputs and one output. Thus the IC has 8 input pins and 4 output pins, one Vcc pin (connected to positive voltage supply) and one Vss (connected to negative supply). Its basic features include – Maximum supply voltage: 15V, Minimum supply voltage: 3V, Maximum speed of operation: 4MHz. It can be used in tone generators, metal detectors etc.
Transistor BC547: It is a NPN bipolar junction transistor and it is used mainly for amplification and switching purpose. Its features include maximum current gain of 800.It is used in CE configuration when used as an amplifier.
Battery: A DC supply of 9V is given through a battery to power up the circuit.