Field of the invention
This invention relates to the field of electronics and Internet of Things. It is an loT based Smart Over Voltage Protection for AC Loads using NODE MCU is implementing to protect the sensitive AC loads from excess voltage as well as Human safety

Need for the Invention
a. The over voltage protection should be done using fast switching
and if the voltage becomes normal after the voltage fluctuation, the system should automatically allow the AC line to the sensitive AC load.
b. The manual operation of changing the FUSE should be avoided as
well as the heat produced by the circuit should also be reduced
and the measured voltage and AC load status should be updated
time to time in the cloud database.
Summary of the invention
The step-down Transformer used to down scale the AC line input voltage from 230 V to 12 V and based on the turns ratio in the transformer, if the voltage is increased at the input side will be reflected at the output side. The bridge rectifier and capacitor filter used to convert the AC component into pulsating DC component and the same is applied to both V - pin of comparator and the analog input pin of Node MCU. Another input pin V + in the comparator is applied with the 12.5 V DC and if the voltage available in the V - pin exceeds the voltage in V + pin, then the output of the comparator will become Zero, otherwise the output of the comparator will be +5 V

DC which controls the relay by applying voltage to the base of the transistor, The Relay is used to protect and control the load from the over voltage based on the transistor switching. The analog pin in the Node MCU will also get the same input voltage through the voltage divider network of R5 and R6 and it will be measured and the same will be updated in the cloud database. The downscaled voltage data is upscaled using the formula included in the Node MCU programming. The DO pin in the Node MCU receive the comparator output Voltage through the voltage divider network of R3 and R4 and the load turn ON status will be updated in the cloud database. Detailed description of the invention
The overvoltage protection for the multiple individual sensitive loads is complicated to implement, because the protection can be done using the Fuse, stabilizer and other protection equipment which cannot have the speed of operation to protect the sensitive load. In this proposed method, the solution for over voltage protection is possible by checking the voltage before getting into the load and if the voltage is up to the mark, then it will allow that voltage to the load and the voltage available in the line can be frequently updated in the cloud database using the microcontroller board Node MCU. If the voltage in the line is high, then the system stops the voltage flow to the sensitive load. Here the implementation is based on the voltage measurement using the comparator and it controls the relay which is connected with the AC load to protect the same AC load. The voltage from the step-down transformer after the rectifier, filter and

comparator is given to the comparator for the comparison of over voltage. Simultaneously, the voltage measured by the Node MCU will be updated in the cloud database time to time with the help of Wi-Fi Gateway available in Node MCU. The step-down Transformer used to down scale the AC line input voltage from 230 V to 12 V and based on the turn's ratio in the transformer, if the voltage is increased at the input side will be reflected at the output side. The bridge rectifier and capacitor filter used to convert the AC component into pulsating DC component and the same is applied to both V - pin of comparator and the analog input pin of Node MCU. Another input pin V + in the comparator is applied with the 12.5 V DC and if the voltage available in the V - pin exceeds the voltage in V + pin; then the output of the comparator will become Zero, otherwise the output of the comparator will be +5 V DC which controls the relay by applying voltage to the base of the transistor. The Relay is used to protect and control the load from the over voltage based on the transistor switching. The analog pin in the Node MCU will also get the same input voltage through the voltage divider network of R5 and R6 and it will be measured and the same will be updated In the cloud database. The downscaled voltage data is upscaled using the formula included in the Node MCU programming. The DO pin in the Node MCU receive the comparator output Voltage through the voltage divider network of R3 and R4 and the load turn ON status will be updated in the cloud database.

Description of Drawings
While the foregoing disclosure shows illustrative aspects of the
disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.

CLAIMS
We claim:
1. An loT based Smart Over Voltage Protection for AC Loads using NODE MCU comprising:
a. Node MCU Development Board
b. Step Down Transformer
c. Bridge Rectifier and Filter
d. Comparator and Transistor
e. Relay
2. An loT based Smart Over Voltage Protection for AC Loads using NODE MCU according to claim 1, includes Node MCU Development Board, which is used to measure the AC voltage and AC load status should be updated time to time in the cloud database.
3. An loT based Smart Over Voltage Protection for AC Loads using NODE MCU as claimed in claim 1, comprising of a step-down Transformer used to down scale the AC voltage from 230 V to 12 V.

4. An loT based Smart Over Voltage Protection for AC Loads using NODE MCU according to claim 1, bridge rectifier and capacitor filter used to convert the AC component into pulsating DC component.
5. An loT based Smart Over Voltage Protection for AC Loads using NODE MCU according to claim 1, the comparator is used to compare the pulsating DC voltage with the 12.5 V reference voltage to control the relay by applying voltage to the base of the transistor.
6. An loT based Smart Over Voltage Protection for AC Loads using NODE MCU according to claim 1, the Relay is used to protect and control the load from the over voltage based on the transistor switching.