Water Tank Overflow Alarm Using Transistor / 555 Timer IC

Water tank overflow is a typical issue that prompts the wastage of water. And it is happened water run out when it is most needed. Even though there are numerous answers like ball valves which consequently stop the water overflow when the tank gets full. To avoid this circumstance we need a water tank overflow alarm for indication.

This project will help you to build such a water tank overflow alarm using BC548 transistors and 555 timer ic. This also keeps informing the user about the water level using LED indicators. It does not only indicate the present water level in the tank but also indicates the dry-out of the tank.

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Transistor-Based Water Tank Overflow Alarm

This simple transistor-based water tank overflow alarm circuit is valuable to demonstrate the water levels in a tank. At whatever point the tank gets filled, we get a caution alarm for specific levels. Here we design three levels that are low, medium, and full (We can make alerts for additional levels). We have added two LEDs to demonstrate the underlying two levels, and one buzzer to show the full level. At this point, when tanks get filled totally we will get a blaring sound from the buzzer.

Circuit Diagram

water tank overflow alarm using transistor

Components Required

  • BC548 transistors
  • 2.2KΩ Resistors
  • 100Ω Resistors
  • Led (Red, Green)
  • Buzzer
  • Wires

Circuit Connection

In this water level indicator, we need to take the three NPN-type transistors and short all three emitter terminals of the BC548 to the ground.

All the collector terminals of each transistor are connected with red, and green LEDs and with a buzzer anode part respectively with 100Ω resistors and all cathodes of these LEDs and buzzer are connected with each other to the Vcc.

At last, all three base terminals are represented as the outputs (L2, L3, L4) of the circuit and attached to the container with 2.2KΩ resistors as shown in the circuit schematic.

A direct positive supply is attached to the bottom of the container (L1).

Working Principle of Water Tank Overflow Alarm Using Transistor

The water level indicator circuit is intended to show three levels of water put away in the tank; low however not vacant, half, and full. 

When there is no water in the tank, all the LEDs are off as a sign that the tank is totally unfilled. 

At the point when the water level increases and arrives at L2, the contacts L1 and L2 get shorted as water goes about as a conducting medium somewhere in the range of L1 and L2. 

This will turn on the transistor Q1 and the green LED begins to sparkle. As the water level keeps on rising and arrives at a large portion of the tank, L3 will come into contact with water and gets a little voltage from L1.

At the point when the water in the tank ascends to a full tank, L4 is additionally shorted with L1 and both Q3 and Q4 will turn on. 

The red LED shines and furthermore, a caution sound is made by the signal as a sign that the tank is full and the water siphon or engine can be powered off.

555 Timer-Based Water Tank Overflow Alarm

Circuit Diagram

water tank overflow alarm using 555 timer

Components Required

  • NE555 Timer
  • 1KΩ Resistor
  • 10KΩ Potentiometer
  • 1uf/25V Capacitor
  • Piezo Buzzer
  • Wires

Circuit Connection

To begin the water level indicator project, we need a 555 timer IC to put on the board and connect pin 8 to the Vcc and pin 1 to the ground.

connect pin 2 and pin 6 with each other and ground with a 1uf/25V capacitor.

Connect pin 4 to the ground through a 1 KΩ resistor. 

A 10 KΩ pot is connected between pin 6 and pin 8 with these side terminals and the middle terminal is connected with pin 7 of the IC.

Then a small piezo buzzer is connected through pin 3 of the IC and a resistor of 1 KΩ is connected between pin 3 and the ground. 

The two input probe is connected with pin 4 and pin 8 of the IC.

Working Principle of Water Tank Overflow Alarm Using 555

The water level indicator circuit utilizes a 555 timer clock in astable mode with R1=22KΩ, R2= 570Ω, and C1=1uF/25V. The recurrence frequency of the given astable circuit is around 62 Hz. 

The two probes which are appeared in the circuit ought to be kept at a significant level for the water. The separation between the probes ought to be not exactly a couple of centimetres to guarantee that the conduction between the probes will occur when water is contacted to these probes. 

At the point when the water level reaches the tallness of the probes, at that point, the 555 timer circuit will get empowered and the output of the 555 timer clock creates a square wave output with a recurrence frequency of around 62 Hz. This output is given to the buzzer.

The logic Implemented in this circuit is, that 555 timer clocks are empowered when their reset pin is associated with a logic high. Yet, at first, it is associated with ground. At the point when the water level is high, this pin is empowered and this drives the 555 timer clocks into the astable mode.

Applications of Water Level Indicator

  • It very well may be utilized in water tanks to control water levels. 
  • Consequently, turn ON/OFF siphons. 
  • Water level indicators can be utilized in manufacturing plants, business buildings, condos, and homes.
  • Fuel tank level checking.
  • Oil tank level control.
  • High and low-level alerts.
  • Pool water level control.
  • Life station switches.

2 thoughts on “Water Tank Overflow Alarm Using Transistor / 555 Timer IC”

  1. That’s water level indicator not an alarm… Alarm is different from indicator am I right.. And where is the buzzer?

  2. Really Appreciate this update, can you make it so I receive an email when you make a fresh post?

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