Water indicator Circuit to measure the level of any liquid
- 1. SIMPLE WATER INDICATOR CIRCUIT TO MEASURE THE LEVEL OF ANY LIQUID Prepared by Baranitharan Computer Science and Engineering Kings College of Engineering
- 2. Components required • Power Supply(6v) • NE 555 timer IC • Resistors (100Ωx2, 10kΩ) • Relay (6V, 30A) • BC 548 transistor x2 • 1N4007 Diode
- 3. Circuit
- 4. How Does It Work • We know the property of 555 timer IC, i.e. its output goes HIGH when voltage at the second pin(trigger pin) is less than 1/3 Vcc. Also we can reset back the IC by applying a LOW voltage at the 4th pin (Reset pin). • In this project 3 wires are dipped in water tank. Let us define two water levels- Bottom (Low) level and Top (Up) level. One of the wire or probe is from Vcc.
- 5. The probe from bottom level is connected to the trigger (2nd) pin of 555 IC. So the voltage at 2nd pin is Vcc when it is covered by water. WHEN WATER LEVEL GOES DOWN, THE 2ND PIN GETS DISCONNECTED(UNTOUCHED) FROM WATER I.E. VOLTAGE AT THE TRIGGER PIN BECOMES LESS THAN VCC. THEN THE OUTPUT OF 555 BECOMES HIGH
- 6. WHILE THE WATER LEVEL RISES, THE TOP LEVEL PROBE IS COVERED BY WATER AND THE TRANSISTOR BECOMES ON. ITS COLLECTOR VOLTAGE GOES TO VCE=0.2. THE LOW VOLTAGE AT THE FOURTH PIN RESETS THE IC. SO THE OUTPUT OF 555 BECOMES 0 VOLT. HENCE THE MOTOR WILL TURN OF AUTOMATICALLY.
- 7. For simple demonstration of this project we can use a DC motor directly at the output of 555 instead of relay. For practical implementation we must use a relay. Rating of relay is chosen according to the load(motor). 32A relay is best suited for domestic applications.
- 8. NE 555 timer IC
- 10. Conclusion It is used to find the level of any liquid It is used to reduce the wastage of any liquid It is used to avoid the electricity consumption. It is used to make our home as smart