Electrical · Protection and monitoring · Final year project
Auto Selection of Any Available Phase in 3 Phase Supply System
An automatic phase changeover for uninterrupted single-phase supply. The circuit monitors all three phases and, if the phase feeding the load fails, switches the load to the next healthy phase through relays.
What is the Auto Selection of Any Available Phase in 3 Phase Supply System project?
An automatic phase changeover for uninterrupted single-phase supply. The circuit monitors all three phases and, if the phase feeding the load fails, switches the load to the next healthy phase through relays.
Key facts
- Branch
- Electrical Engineering (EE / EEE); also suits E&TC / ECE
- Type
- Final year project · Intermediate
- Suitable for
- Diploma capstone and B.E / B.Tech final year
- Build time
- 4 to 6 weeks
- Estimated component cost
- ₹2,600 – ₹3,800
- Guidance from
- ₹9,999 (Hardware / IoT Final Year)
How the Auto Selection of Any Available Phase in 3 Phase Supply System works
- Voltage regulator / buck converter and 12 V power adapter / step-down transformer supply the circuit; a regulator gives the controller and sensors a steady 5 V.
- The Push buttons and switches provide manual inputs and the power switch.
- The Arduino Uno R3 reads the inputs, runs the decision logic written in C/C++ and drives the outputs.
- The Relay module switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal.
- The LEDs indicate status.
Block diagram
Inputs
Push buttons and switchesController
Arduino Uno R3Outputs
Relay moduleLEDsComponents list and cost
Typical prices from Indian online stores and electronics markets (Lamington Road, Budhwar Peth, SP Road). Buy from one store where you can to save on shipping.
| Component | Qty | What it does | Approx. cost |
|---|---|---|---|
| Arduino Uno R3 | 1 | Reads the inputs, runs the decision logic written in C/C++ and drives the outputs. | ₹550 |
| Push buttons and switches | 3 | Provide manual inputs and the power switch. | ₹120 |
| Relay module | 1 | Switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal. | ₹70 |
| LEDs (assorted) | 1 | Indicate status. | ₹20 |
| Voltage regulator / buck converter | 1 | Provides a steady voltage to the controller and sensors. | ₹80 |
| 12 V power adapter / step-down transformer | 2 | Supplies stable low-voltage power from the mains. | ₹500 |
| Passive components, PCB and wiring kit | 1 | Resistors (assorted), diodes, capacitors (assorted), crystal oscillator, transistors / MOSFETs, cables, connectors and jumper wires, PCB / breadboard and ICs and IC sockets. | ₹445 |
| Wiring, PCB, soldering and enclosure | 1 | Project overhead | ₹450 |
| Demo model base / mounting board | 1 | Project overhead | ₹500 |
| Testing spares and replacements | 1 | Project overhead | ₹300 |
| Estimated total | Varies with brand, quality and city | ₹2,600 – ₹3,800 |
Prices are estimates for budgeting. We confirm the bill of materials when your design is frozen, and components are charged at actual cost with bills.
How much does this project cost?
| Option | What you get | Cost |
|---|---|---|
| Components only | You buy the parts and build it yourself | ₹2,600 – ₹3,800 |
| Hardware / IoT Final Year | Working model or guided build, Circuit diagram and bill of materials, Firmware / code with explanation | from ₹9,999 + components |
| Capstone Project (CPE) | Working project or model, Black book in MSBTE format, Step-by-step explanation | ₹9,999 + components |
| Diploma ITR | 100% working source code, Project report PDF, PPT | ₹1,999 + components |
No GST and no hidden charges. Use the cost calculator for a quote with your deadline and add-ons, or see all plans.
Download the project brief (PDF)
Summary, working, components and cost and viva questions on one branded PDF to show your guide or team. To get it developed, contact us on WhatsApp.
What you submit with this project
- Working model with circuit diagram and program code
- Project report or black book in your university's chapter order (block diagram, circuit, calculations, results)
- Presentation for the review and final viva
- Synopsis for topic approval, if your college asks for one
Electrical viva questions on this project
What is the aim of the Auto Selection of Any Available Phase in 3 Phase Supply System project?
An automatic phase changeover for uninterrupted single-phase supply. The circuit monitors all three phases and, if the phase feeding the load fails, switches the load to the next healthy phase through relays.
Explain the working of your project in short.
Voltage regulator / buck converter and 12 V power adapter / step-down transformer supply the circuit; a regulator gives the controller and sensors a steady 5 V. The Push buttons and switches provide manual inputs and the power switch. The Arduino Uno R3 reads the inputs, runs the decision logic written in C/C++ and drives the outputs. The Relay module switches mains or high-current loads such as lamps, pumps and fans from a low-voltage signal.
What microcontroller is on the Arduino Uno and what are its key specifications?
The Uno uses the ATmega328P: 8-bit, 16 MHz clock, 32 KB flash, 2 KB SRAM, 14 digital I/O pins (6 PWM) and 6 analog inputs with a 10-bit ADC.
Why is a pull-up resistor needed with a push button?
Without it the input pin floats and reads random values. The pull-up keeps it HIGH until the button connects it to ground.
Why is a relay used?
It electrically isolates the 5 V control circuit from the high-voltage load. The controller energises the coil through a transistor, and the contacts switch the load.
Why is a resistor connected in series with an LED?
It limits the current to a safe value (about 10–20 mA). Without it, the LED would draw too much current and burn out. R = (supply voltage − LED voltage) ÷ current.
What does the 7805 regulator do?
It is a linear regulator that gives a constant 5 V output from 7–35 V input. A buck converter does the same more efficiently by switching.
How did you calculate the power rating of your system?
Using P = V × I for each load, adding a margin of 20 to 25%.
What protection have you provided in the circuit?
A fuse against short circuit, relays or optocouplers to isolate the control side from the power side, flyback diodes across inductive loads such as relays and motors, and software limits that cut off on over-current or over-voltage.
What is the efficiency of your system and how did you measure it?
Efficiency = output power ÷ input power × 100. We measured input and output voltage and current with a multimeter at different loads and tabulated the results in the report.
Explain the block diagram of your project.
The input section senses the real-world quantity, the Arduino Uno R3 processes it according to the program, and the output section displays the result and drives the actuators. The power supply section feeds every block.
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