Water Level Indicator Electronics Project

Water Level Alarm Using 555 Timer

The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator, and as a flip-flop element. Derivatives provide up to four timing circuits in one package.

Introduced in 1971 by American company Signetics, the 555 is still in widespread use due to its low price, ease of use, and stability. It is now made by many companies in the original bipolar and also in low-power CMOS types

Specifications for 555

These specifications apply to the NE555. 
specifications depending on the grade (military, medical, etc.).
Supply voltage (VCC)                  4.5 to 15 V
Supply current (VCC = +5 V)          3 to 6 mA
Supply current (VCC = +15 V)       10 to 15 mA
Output current (maximum)             200 mA
Maximum Power dissipation           600 mW
Power consumption (minimum operating)     30 mW@5V, 225 mW@15V
Operating temperature                 0 to 70 °C

Here we are using a simple and low cost hardware using 555 Timer Circuit.

Our aim is to make a water level detecting alarm with simple and low cost hardware without compromising on the performance of the device.

Water Level Alarm Using 555 Timer Circuit Diagram:

The circuit uses a 555 timer in astable mode with R1=220 ohms, R2= 150 ohms and C1=1 uF.

We know, the frequency of operation of the IC 555 in astable mode depends on the values of R1, R2 and C1. By calculating the frequency of the given astable circuit, we get the frequency to be around 1.18KHz. 

The frequency at which it operates is in the audio frequency.

The 1K Resistor R3 whose ends are connected to pin-4 and ground disables the circuit by default and it enables when the water reaches its full level when the probes get dipped in water.

The two probes which are shown in the circuit should be kept at the high level for the water. The astable multivibrator in the circuit is normally disabled and it gets enabled only when the probes touch the water. 

The distance between the probes should be less than a few centimetres to ensure that the conduction between the probes will take place when water is touched to these probes. 

When the water level rises to the height of the probes, then the 555 circuit will get enabled and the output of the 555 timer produces a square wave output with a frequency of about 1.18Khz. 

This output is given to the mini loudspeaker which then beeps at an audio frequency of 1.18KHz.

The dual version is called 556. It features two complete 555s in a 14 pin DIL package.

The quad version is called 558 and has 16 pins. To fit four 555s into a 16 pin package the power, control voltage, and reset lines are shared by all four modules. Each module's discharge and threshold circuits are wired together internally

 

The Logic behind the project is simple, now its up to you that what changes can you make in the given project. For e.g. You can develop an android app and use a GSM module to get instant alert on your smart phone.

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