1) INTRODUCTION
2) CIRCUIT DIAGRAM
3) HOW IT WORKS
4) COMPONENETS DESCRIPTION.
A. IC 555 TIMER
B. BC 547 TRANSISTOR
C. RESISTER
D. CAPACITOR
E. PRESET
F. BUZZER
G. PCB
5) SCOPE
1) INTRODUCTION:
Generally when we are pumping liquids like water or may be any other liquid is we need a human to see whether the tank is filled or not or we will place a overflow pipe to know that the tank is fill or not in case of water tank and we get confirmed from the water coming from overflow pipe that the has been filled. here is lots of wastage of water and still we need a human to have a look over it and so to avoid this and to save wastage of water or any other liquid that is being filled. Here is a simple circuit for liquid level alarm this circuit only tells us when the tank is full with a beep sound. It is built around two BC547 transistors (T1 and T2) and two timer 555 ICs(IC1 and IC2). Both IC1 and IC2 are wired in a stable multi vibrator mode. Timer IC1 produces low frequency, while timer IC2 produces high frequency. As a result, a beeping tone is generated when the liquid tank is full. Initially, when the tank is empty, transistor T1 does not conduct. Consequently, transistor T2 conducts and pin 4 of IC1 is low. This low voltage disables IC1 and it does not oscillate. The low output of IC1 disables IC2 and it does not oscillate. As a result, no sound is heard from the speaker. But when the tank gets filled up, transistor T1 conducts. Consequently, transistor T2 is cut off and pin 4 of IC1 becomes high. This high voltage enablesIC1 and it oscillates to produce low frequencies at pin 3. This low-frequency output enables IC2and it also oscillates to produce high frequencies. As a result, sound is produced from the speaker. Using preset VR1 we can control the volume of the sound from the speaker. The circuit can be powered from a 9V battery or from mains by using a 9V power