Protection circuits like reverse polarity protection short circuit protection and over under voltage protection are used to protect any electronic appliance or circuit from any sudden mis happening generally fuse or mcb is used for overvoltage protection here in this circuit we will build an overvoltage protection circuit without using fuse.
Under voltage protection relay circuit diagram.
The maximum limit for input line voltage is 140 v.
This circuit protects from high voltage.
This is a safety device to overvoltage.
High voltage low voltage cut off circuit.
The overcurrent relay is used to protect the alternator or generator against overloading and which trip the circuit breaker.
Now let s consider the under voltage condition.
Phase failure and under over voltage master control motor circuits protection relay in this video we can see you full introduction these protection of motor with zahra rst 25 master control relay.
After that relay rl 2 get energized and the boosted voltage shows up at the n o contact rl 1 b of relay rl 1 but under two conditions relay rl 1 lies in de energized condition.
Thus the output of operational amplifier n2 goes high and it energizes the relay through.
Overvoltage protection circuit using timers.
When the line voltage is below 180 v the voltage at the inverting terminal pin 6 of operational amplifier n2 is less than the voltage at the non inverting terminal 6 v.
This is a shunt regulator diode.
Another important criteria in overcurrent element is protection against.
Short circuit protection reverse polarity protection and over under voltage protection are some of the protection circuits that are used to protect any electronic appliance or circuit from any sudden mishappenings.
As per datasheet tl431a is the three terminal programmable integrated circuit.
First when the input line voltage is controlled by trim pot vr 1 and is below 170v threshold voltage level.
Over voltage and under voltage circuit using comparator.
Over voltage protection circuit using tl431 shunt regulator ic.
Automatic equipment disconnect when the power cross the level of a fixed voltage.
The components required for the block diagram of the comparator circuit is the power supply step down transformer bridge rectifier two preset pins comparators voltage regulator relay buzzer and ac current this circuit is planned to expand a low voltage and high voltage tripping mechanism to protect the load from the damage.
Second due to initial shunting effect of capacitor c.
As explained above the transistors sense the presence of the dangerous voltage levels respectively and activate.