Are you tired of manually switching between DC power supply and battery backup during load shedding? ⚡ Then this project is for you!

In this article, we will show you how to make a DC Changeover for Automatic Inverter System using a simple relay-based circuit. With this DIY Inverter Changeover Switch, your load (fan, light, router, or any DC appliance) will automatically switch between battery and DC adapter without any interruption.

⚡ What is a DC Changeover System?

A DC changeover system is a circuit that automatically shifts the load between two DC power sources – for example:

DC Adapter / Power Supply (main power)

Battery Backup (inverter or UPS system)

When the main power is available, the load runs directly from it. When the main power fails, the relay automatically switches the load to the battery backup system. This ensures continuous operation without manual switching.

🛠️ Components Required

Here’s the complete component list for building this automatic inverter changeover system:

DC Input Connector (DC-072 type)

Diode 1N5822 (Schottky Diode) – 1 pcs

Diode 1N4007 – 2 pcs

Relay SPST (Single Pole Single Throw) – 1 pcs

Electrolytic Capacitors (1000µF, 25V) – 2 pcs

Battery Connector (2-pin)

Load Connector (2-pin)

PCB / Breadboard for connections

Wires & Soldering tools

⚙️ Circuit Diagram Explanation

Below is the attached circuit diagram of the DC changeover system:

📌 Working Principle:

The DC Adapter (main supply) is connected through diode D1 (1N5822) to the load.

The Battery is connected through D2 (1N4007) and controlled by the Relay.

When the main DC supply is present, the relay is energized and powers the load directly through D1.

When the main power fails, the relay deactivates, and the battery takes over instantly through D2, ensuring the load is never disconnected.

Capacitors U2 & U3 (1000µF) help to stabilize the voltage and reduce switching noise.

Diode D3 protects the relay coil from reverse voltage spikes.

This way, the load (fan, router, or LED light) never turns off and runs seamlessly between DC adapter and battery backup.

🔌 Applications of Automatic DC Changeover

This DIY automatic inverter changeover switch can be used in many real-life applications:

✔️ WiFi Router UPS – Keeps your internet running during power cuts.

✔️ DC Fan Backup – Runs fans continuously without manual switching.

✔️ LED Lights – Automatic backup lighting system.

✔️ Small Inverter System – For powering low-watt appliances.

✔️ Electronics Projects – Continuous power supply for Arduino, Raspberry Pi, and microcontroller projects.

🚀 Advantages of This Circuit

✅ Fully automatic (no manual switch needed)

✅ Protects devices from power interruption

✅ Simple design with few components

✅ Works for both 12V DC and 5V DC systems

✅ Can be customized for different load requirements

📹 Watch Full Video Tutorial

📝 Final Words

Building an Automatic DC Changeover for Inverter System is one of the most useful DIY electronics projects. It not only provides uninterrupted power but also protects your devices during sudden power failures.