This one may be your next science project. It is a very simple LED indication based water level indicator using CMOS IC4049. The CMOS technique has a very high gain to sense an small amount of current. In this project, a number of sensing probes(simply wires) are placed in various level of water inside a tank or container.
This is a sample of built project.
A small piezo buzzer is also connected for alarm when the level is at the maximum condition. The whole arrangement is assembled in a wooden box in order to beautify the project where the LEDs are placed one by one with respect to the level of water.
Here are the required parts:
- IC CD4049
- PNP Transistor BC558
- Transformer 9V-500mA
- Diode 1N4007 X 2
- LED X 6, one extra LED for power supply indicator
- Capacitor 470uF/16V
- Resistor 2.2kΩ
- Resistor 1kΩ
- Resistor 100kΩ X 6
- Resistor 470Ω X 6
Description: The working of the circuit is based on the conduction of small amount of current through water molecules. The current is feeding from the step down transformer and hence finally sensed and controlled at the input pins of ic4049 which is basically a hex inverter cum buffer. The output is transferred in the form of voltage across the LEDs. Hence LED glows to show the different level of water.