# Overload and Underfrequency circuit breaker Bangla With English subtitle by hadiul

Hie , I am Sojib .this is our project overload and under frequency circuit breaker there are some parts of this project , firstly microcontroller part secondly AC to DC convertion part thirdly the load part where we can vary the system load. here is a LCD to observe our output current and frequency . and here is a relay ,with this relay we can break the circuit after achiving the condition . we set our condition as the circuit will break if the line current exceeds 25 m A and if the frequency goes below 30 Hz this is a AC signal generator with a frequency 50 Hz sine wave. and finally this is DC voltage source that will give 5 V DC continuously when we have 100 ohm resistor as load our output current is 18 mA and frequency is nearly 52 Hz. now if we increase the load by 100 ohm the current will increase upto 22 mA t~ 24 mA (flacktuating) and the frequency is constant because we didn’t increase frequency . now this below the condition so the circuit won’t break. but if we again connect a 100 ohm resistor parallely the final current will be 26 mA which is over the conditional current so the relay will be on to break. the circuit . now we will check the circuit for variable frequency .You see ,from the signal generator we can vary the frequency now the frequency is 50 Hz and the current is 20 mA now if we decrease the frequency step by step we will see that the current will also decrease. now it is 37 Hz and the current is 16mA . if we decrease the frequency further below 30Hz the relay will againg be on and the circuit will break now the frequency is below 30 Hz . So the circuit will be cut off to save the line from being damaged . so the relay is active and the current is now 0.000000000 😛 So our purpose was to make a project to make a circuit breaker that will be active over 25 mA and below 30 Hz .and you see it is now actually working . আশা করি এই মাঞ্জা মারা ভিডিও দেখিয়া তুমি পুলকিত হইয়াছ । তাই ধইন্ন বাদ । thanks