Water pump controller circuit will automatically stop the motor pump when the tank is full.
At many times when the water tank is empty, we start the motor for storing the water in the tank and get busy in other works. Then we forget to switch off the water pump motor after the tank is full. In this case, water is overflow from the tank and unusually an amount of water is wasted. This Automatic Water Pump Controller circuit is best suited for the submersible motor pump.
We need to save water from wastage by overflowing. Electricity is also more extra consumed by motor when motor is running after the tank is full, so it is difficult to stop the motor manually at the exact time when the tank is full if your water tank is so far from than a living room.
A simple but very reliable and effective Automatic water pump controller circuit diagram is shown here, which able to stop the motor pump automatically when the tank is full. The circuit uses 1 transistor, 1 NE555 timer IC, a relay and few passive components. The circuit is completely automatic which stops the pump motor when the water level in the overhead tank goes to a preset (at top) level. Switches OFF the pump when the water level in the overhead tank goes to touch with top-level wire fitted in-tank i.e the full level.
Connect the circuit diagram as shown in fig and use dc power supply by battery or adaptor to operate this circuit. This circuit works well with 12v DC power. Two wires positioned as a sensor, one at the bottom level of the tank and one is the upper top level where required to before overflow. Use 12v relay of min 25 Ampere load capacity. The circuit is easy to construct and economical, high reliable.
when the water level goes high to reach upper wire contacts, the voltage at pin 6 of ic goes high and then the internal S-R flip flop of ic goes in sets and its output goes low. This low output at pin 3 switch off the transistor and de-energizes relay and disconnects the motor power supply
When the water level of the tank goes below the low level, the voltage of pin 2 of ic becomes low. The internal flip-flop of ic resets and its output goes high. This high output at pin 3 switch on the transistor in on state and then relay energizes the relay.
Transistor– BC547(for small pcb mount relay), 2N2222 for high current Load relay
Circuit diagram 2
The motor will start only when the Water level goes below from the middle wire means the motor will not start again until level goes below half. This circuit working in the bistable mode of 555 timer .