Simple 4 LEDs Water Level Indicator Circuit

Water conservation is a priority and technology like electronic can help.

This article teaches you how to construct a simple circuit for a water level indicator.

It is far less expensive than purchasing one from a store and by using common parts.

This circuit shows the water level remaining in a tank or barrel using LEDs.

It is an excellent project indicating by when the water will fill up without wasting it.

What is a 4 LEDs Water Level Indicator Circuit:

A simple electronic circuit that uses four LEDs as a water level indicator is used to monitor the water level in a tank or container.

In simple terms, the circuit is made up of four LEDs that blink when the water level rises.

Each LED represents a certain level and more LEDs flash to indicate the rising water level as it rises.

Circuit Construction:

Parts List:

• Use insulationless wires removing the insulation plastic to expose the conducting core.
• Place the common supply wire at the bottom of the water tank ensuring it is below the L1 wire.
• Position the level wires L1, L2, L3 and L4 at different height levels in the water tank.
• Connect each level wire to a separate transistor base Q1 to Q4.
• Connect transistors Q1 to Q4 to LED indicators.
• Power the circuit with a 9V battery.

Working Principle:

When the circuit is supplied with power all transistors function as switches.

Without a base supply the transistors act as open switches.

As the tank water level rises the common supply wire connects with the level wires L1 to L4.

The corresponding transistor receives a base supply and acts as a closed switch.

LEDs connected to the transistors illuminate indicating the respective water level has been reached.

Formulas:

Below are the formulas for Simple 4 LEDs Water Level Indicator Circuit:

Base Supply Voltage Vbase:

The base supply voltage is measured by the resistance Rbase​ and the current flowing through the base Ibase​ of the transistor.

V_base = I_base × R_base

here,

• Vbase (Base Voltage) is the voltage that is applied between a transistors base terminal B and emitter terminal E.
• Ibase (Base Current) is an illustration of the current entering the transistors base terminal.
• Rbase (Base Resistor) is resistor attached to the transistors base terminal and biasing voltage source (usually ground or the power supply).

For a particular base voltage Vbase the quantity of base current Ibase that flows is calculated by the value of Rbase.

LED Current ILED​:

The current through the LEDs is measured by the LED forward voltage drop VLED​ and the LED series resistance RLED​.

I_LED = V_battery − V_LED / R_LED

here,

• ILED is a milliampere (mA) representation of the current passing through the LED.
• Vbattery is an indication of the battery voltage that powers the LED circuit.
• VLED (LED Forward Voltage) is a forward biased LEDs distinctive voltage drop across it is what enables it to conduct current and produce light.
• RLED (LED Series Resistor) limits the amount of current that passes through the LED by being linked in series with it.

Based on the VLED, Vbattery and intended LED current ILED the value of RLED is selected.

Different LED colors usually have different forward voltage dips which is generally between 1.8V and 3.3V.

Note:

These calculations offer a more thorough understanding of the water level indicator circuits electrical properties.

For best results resistor values and component specifications are adjusted based on these calculations.

Conclusion:

By following these construction and working guidelines you can assemble an efficient and budget friendly water level indicator circuit.

This simple 4 LEDs water level indicator circuit empowers households to avoid the unnecessary loss of overflow water promoting responsible water usage and conservation.

References

How to Make a Water Level Indicator

Water level indicator LEDs one by one