Introduction

Rice field requires plenty of water for growth of plants. During the initial period to mature stage of the plant a water level should be maintained for different agricultural activities. By using modern engineering and technology in this project we are maintaining the water level automatically. As this is an automatic process regular human observation is not necessary. So, human effort is reduced here. It promotes better plant growth. By applying this method more crop production is possible.

Block diagram

Materials required

1. Water pump
2. Transformer
3. IC 555
4. Resistors
5. capacitors
6. Hard board
7. LED
8. Wires
9. Screws
10. Frames
11. Switch
12. Probe
13. Vero board
14. Relay  
15. Transistor
16. Diode

Components Description

Resistor

A resistor restricts the flow of current. The resistors used here are carbon film and quarter watt type.

Capacitor

A capacitor stores electric charge. Capacitors used here are electrolytic and ceramic type.

LED (Light Emitting Diode)

It is a transducer which converts electrical energy into light energy.

Transistor

A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit. BC 547 is a general purpose transistor. It is an npn epitaxial silicon transistor. Its maximum collector current (DC) is 100mA.

NE 555

The 8-pin NE 555 timer is the most useful ICs ever made in the world. Its popular name is timer IC. It is used in many electronics projects. Just adding a few external components, it can be used to construct so many circuits. The 555 has three operating modes: Monostable mode, Astable mode and Bistable mode. It can withstand maximum supply voltage up to 16 volt. It has a maximum power dissipation up to 600mW.

Relay

Generally relay is defined as an electromagnetic switch. The relay used here is a 12 volt ice cube type.

Diode 1N4007

These are general purpose diodes. These diodes have high current capability and low forward voltage drop. The average rectified output current is one ampere.

Transformer

It consists of two coils of insulated copper wire linked by an iron core. Transformers are used to step up (increase) or step down (decrease) AC voltages. Energy is transferred between the coils by the magnetic field in the core. There is   no electrical connection between the coils. Here we have used a shell type step down transformer which step downs 230 volt AC to 12 volt AC. It can supply maximum 750 mA current.

Water pump

Here we are using a centrifugal submersible type water pump. It takes 230 volt ac for its operation

Working

When water touches the probe it sends a specific signal to the circuit otherwise not. Thus, controlling the water pump operation and maintaining previously specified water level of the rice field.

Construction

The project is assembled on the board according to the circuit diagram. Water pump is submerged in water bucket.

Power supply circuit
The bistable circuit here operates through 12 V DC. The full bridge rectifier converts 12 V AC into 12 V DC and filtered by the 1000 µF capacitor. The advantage of using a bridge rectifier circuit is, we will get full wave rectification by using four diodes. The LED in series with 1 kΩ resistor is just for power indication purpose.

Scientific reason

When the water level of rice field goes below the lowest level, the internal SR-flip-flop of IC resets and drives relay driver transistor and energies relay to activate water pump.  It starts filling water in the field.

When the water level goes high and reaches the highest level, internal SR-flip-flop of IC sets and cuts off relay driver transistor and de-energizes the relay. Water pump is disconnected from the mains power supply. This stops the water flow.

Bistable multivibrator

As the name indicates bistable, it has two stable states. That means the circuit can show two different fixed behaviors by getting external triggering pulse. Particularly in this project up to the lowest water level the pump remains in inactive state. When the water level of rice field goes below the lowest level, the internal SR-flip-flop of IC resets and this state is maintained. When the water level goes high and reaches the highest level, internal SR-flip-flop of IC sets and this state is maintained.

Advantage

1. Regular human observation is not required as this is an automatic process. So, human effort is reduced
2. Better plant growth.
3. More crop production.

Contact:
Er. Anil Kumar Prusty.
Phone:- +91 9861004895