Over Voltage Under Voltage Protection System Using Arduino

Over Voltage and Under Voltage Protection System Using Arduino

Project Overview

The Over Voltage and Under Voltage Protection System using Arduino is a smart electrical safety system designed to protect household and industrial electrical appliances from damage caused by voltage fluctuations. Voltage instability—such as over-voltage or under-voltage—can seriously harm sensitive electronic devices. This project continuously monitors the input AC voltage and automatically disconnects the load whenever unsafe voltage levels are detected, ensuring safe and reliable operation.

The system uses an Arduino microcontroller to process real-time voltage data and control relays that connect or disconnect the load based on predefined safe voltage limits.

Objectives of the Project

• To continuously monitor AC supply voltage

• To detect over-voltage, under-voltage, and normal voltage conditions

• To automatically protect electrical loads from unsafe voltage

• To provide real-time voltage display on an LCD

• To improve electrical safety and increase appliance lifespan

System Working Principle

1. Voltage Sensing
   The AC supply voltage is stepped down and isolated using a voltage sensing circuit. The reduced voltage is converted into a safe DC signal readable by the Arduino.

2. Arduino Processing
   The Arduino continuously reads the sensed voltage through its analog input pin. The voltage value is calculated and compared with predefined threshold limits:

   • Under Voltage Limit

   • Normal Voltage Range

   • Over Voltage Limit

3. Decision Making

   • If voltage is below the lower limit, the system identifies an under-voltage condition.

   • If voltage is within the safe range, the system operates normally.

   • If voltage is above the upper limit, the system identifies an over-voltage condition.

4. Load Control via Relay
   A relay module is controlled by the Arduino:

   • Load is disconnected during over-voltage or under-voltage.

   • Load is connected during normal voltage conditions.

5. Status Indication

   • Indicator bulbs show voltage status (Over / Normal / Under).

   • An LCD display shows real-time voltage, current status, and system condition.

Main Components Used

• Arduino Uno

• Voltage Sensor Module

• Relay Module

• LCD Display (16×2)

• Step-down Power Supply

• Indicator Bulbs (Over / Normal / Under)

• Resistors, capacitors, diodes

• Push buttons (manual control/testing)

Features of the System

• Real-time voltage monitoring

• Automatic load protection

• Clear visual indication using bulbs

• LCD display for voltage and system status

• Reliable and fast response to voltage changes

• Low-cost and energy-efficient design

Applications

• Home electrical appliance protection

• Industrial equipment safety

• Power distribution panels

• Laboratories and educational institutions

• Sensitive electronic devices protection

Advantages

• Prevents damage due to voltage fluctuations

• Increases appliance lifespan

• Fully automatic operation

• Easy to install and modify

• Cost-effective compared to commercial protection devices

Future Enhancements

• Integration with IoT platforms for remote monitoring

• GSM or Wi-Fi alerts for voltage faults

• Data logging of voltage history

• Mobile app-based control and notifications

Conclusion

The Over Voltage and Under Voltage Protection System Using Arduino is an efficient, reliable, and affordable solution for safeguarding electrical equipment from harmful voltage conditions. By combining real-time monitoring, automatic control, and clear user feedback, this system ensures electrical safety and enhances overall power system reliability.