Thus this circuit will not only cut off during low voltages but also will provide a total over voltage protection to the entire house or premises.
Over voltage cutoff circuit.
And when the voltage decreased at a normal level then automatic on the supply.
This is an over and under voltage protection circuit device sound disappeared.
Since in this project batteries with cut off limit of 4 2 v are used for power supply so using two batteries in series set the cut off limit to 8 4 v.
The circuit of auto cut circuit for over and under voltage can only operate in range of 160v ac to 270v ac other than this range of voltage i e.
When the input voltage goes high then the relay will be activated and also when the input voltage is below then required level then relay activated.
When too much voltage 220v and protection when pressure is too low with using the relay cut off power when voltage problems.
Over voltage and under voltage protection circuit for high and low voltage cutoff.
This circuit automatically cuts the current supply to any appliance from the input circuit.
Practically the protection circuit designed in this electronics project cuts off the battery from the charger when the battery voltage goes beyond 8 37v.
The circuit is designed from low cost.
Overvoltage protection circuit using timers.
This circuit is a modified version of the previous one and is able to switch of the load and itself in case the input voltage reaches dangerous levels.
In most of the commonly used portable electronics devices like laptops smart phones and others the li ion batteries with 4 2 v of peak limit of the terminal voltage are used.
The ultimate high low voltage protector circuit.
The potentiometer vr1 is connected to timer 1 for under voltage cutoff and the vr2 is to second timer for over voltage cutoff.
Though the circuit is reasonably accurate the window threshold is too wide meaning the circuit triggers only for voltage levels above 260v and below 200v or above 130v and below 100 v for 120 v normal supply inputs.
If you use this circuit for autocut on over 6v then use 6 v relay and circuit need 6v.
The two transistors are connected to two timers for making switch logic.
If any device needs 12v to work properly then this can be damaged by increasing the voltage.
So it helps to protect the circuit damage by the high voltage.
In particular if the voltage of the motor is lower the coils of it can be a burn.
Under 160v ac or over 270v ac the relay connected to the output of ic 3 is deenergized as a result load will be off.
This voltage sensor circuit can be used to protects any appliance to voltage fluctuation.
