🔋 How to Make a Hybrid Solar-Based WiFi Router/ONU UPS (12V, 9V, 5V Output) | Full Circuit Guide

Are you tired of losing your internet connection during power cuts? In this DIY project, we'll show you how to make a Hybrid Solar-based WiFi Router/ONU UPS that provides uninterrupted power to your WiFi router, ONU, or any DC device using a lead-acid battery. This system offers 12V, 9V, and 5V outputs, making it perfect for routers, ONUs, microcontrollers, and even USB devices.

🔧 Project Overview

This project is based on a carefully designed Hybrid UPS Circuit that can draw power from a DC adapter, lead-acid battery, or solar panel (via external charge controller). The smart switching mechanism ensures that power is always supplied to your router without interruption.

Components Required

1. 1 × LM2596T-5.0 (Fixed 5V Buck Converter)
2. 1 × LM2596T-ADJ (Adjustable Buck Converter – Set to 9V)
3. 1 × LM2596T-5.0 (Fixed 12V Buck Converter)
4. 1 × IRF9540 P-Channel MOSFET
5. 9 × 1N5822RLG Schottky Diodes
6. 4 × 470uH Inductor
7. 8 × 220uF Electrolytic Capacitors
8. 1 × 10kΩ Resistor
9. 1 × 330Ω Resistor
10. 1 × 1kΩ Resistor
11. 1 × 220Ω Resistor
12. 1 × DC Power Jack (FIX9V/12V DC-072-165A)
13. 1 × Battery Connector (2-Pin Screw Terminal or TH-2P-5.00)
14. 1 × USB Type-A Female Port
15. 3 × 2-Pin Header Connectors (for 12V, 9V, 5V Outputs)
16. 1 × 10V Zener Diode
17. 1 × 12V Sealed Lead Acid Battery
18. 1 × External Solar Charge Controller (for charging the battery)
19. Wires, solder, perfboard or custom PCB
20. Optional: Heatsinks for LM2596 ICs

The circuit is divided into key sections:

🔌 1. Power Inputs

1. Adapter Input (DC-072-165A) for mains power.
2. Battery Connector (CONN-TH_2P) for 12V sealed lead acid batteries.
3. Solar Power (Optional) – Use external solar charge controller to recharge battery.

🔄 2. Changeover and Protection

1. Schottky Diodes (1N5822RLG) prevent reverse current.
2. IRF9540 P-Channel MOSFET acts as an automatic switch between adapter and battery.
3. When adapter is available, the MOSFET turns OFF, supplying power from adapter. If adapter fails, the MOSFET turns ON, switching to battery.

⚡ 3. Voltage Regulation Sections

1. LM2596T-5.0 & LM2596T-ADJ Buck Converters:
2. Provide fixed 12V, 9V, and 5V outputs.
3. Each section includes inductors (470uH), capacitors (220uF), and Schottky diodes for stable and ripple-free output.

🔋 4. Output Terminals

1. J2, J3, J4 Connectors deliver 12V, 9V, and 5V regulated outputs.
2. USB Output (USB2-Type A Female) for 5V mobile charging or power banks.

1. Assemble the circuit on a PCB or perfboard following the schematic.
2. Ensure proper heat dissipation for the LM2596 ICs.
3. Use thick wires for battery and adapter input.
4. For solar charging, connect the solar panel to the external charge controller, and route it to the battery.

1. Always use a fused input line to prevent overload.
2. Make sure to charge and maintain the lead-acid battery properly.
3. Keep the circuit in a ventilated enclosure to avoid overheating.

This DIY Hybrid WiFi UPS circuit is perfect for anyone who wants uninterrupted internet during power failures using solar energy or batteries. Whether you live in an area with frequent blackouts or want to experiment with solar backup systems, this project is both affordable and reliable.