Friday, February 3, 2012

Water Level Indicator With 7-Segment Display

Water Level Indicator With 7-Segment Display 

Circuits available for indicating water level is usually consist of LEDs to indicate the liquid level. But this circuit uses a 7-segment LED display instead of normal LED's for numeric display of water level.Moreover, a buzzer is used to alert you of water overflowing from the tank. The circuit shows the water level by displaying L, H and F for low, half and full, respectively. You can use this circuit for water tank motor control or a stand alone circuit.


This circuit uses Five sensors to sense water levels in the tank. When the tank is empty, the input
pins of IC 7404 (NOT gate IC) are pulled high via a 1M ohm resistor. So it outputs a low voltage. As water starts filling the tank, a low voltage is available at the input pins of the gate and it outputs a high voltage.

When the water in the tank rises to touch the low level sensor, pin 5 of gate N3 gets a low voltage and results in high output at pin 6. Pin 6 of the gate is connected to pin 10 of gate N9, so pin 10 also goes high. Now as both pins 9 and 10 of gate N9 are high, its output pin 8 also goes high. As a result, positive supply is applied to DIS3 and it shows ‘L’ indicating low level of water in the tank.
Similarly all levels are displayed in the numeric display.

Assemble the circuit on a strip board and enclose within a non corrosive material. Use a 5V regulated supply for powering the circuit.

                                                                            Submitted By
                                                                                                                              Hasifnoor_Attasheri
                                                                                                          Thank you !
                                                                                                          God Bless You

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