Today we are going to demonstrate a circuit of 5V, 6V, and 9V Automatic UPS Or Battery Backup Project. This circuit is using a voltage regulator IC of the LM79xx series where xx is the desired voltage. You can use LM7805 when using a 5V battery, LM7806 while using a 6V battery, and so on. This circuit is of good quality and provides an uninterrupted supply of your desired voltage. It is using an SLA battery of any capacity ranging from 7AH to 12AH.
Hardware Components
The following components are required to make UPS Or Battery Backup Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Transformer | 110 or 230V/12V 1A | 1 |
| 2. | Diode | 1N5400, 1N4148 | 5, 2 |
| 3. | Zener diode | 9.1V | 1 |
| 4. | Battery | 12V 7AH – 12AH | 1 |
| 5. | Capacitor | 1000µF/50V, 0.47uF, 100nF | 1, 1, 1 |
| 6. | Resistor | 1K, 470Ω, 10K Var | 3, 1, 1 |
| 7. | Voltage Regulator IC | LM7805 | 1 |
| 8. | Transistor | 2N4401, 2N4403 | 1, 1 |
| 9. | Switch | – | 1 |
| 10. | Relay | 12V | 1 |
| 11. | LED | Green | 1 |
LM7805 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM7805
2N4403 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 2N4403
UPS Or Battery Backup Circuit
Working Explanation
This circuit can be easily built and adjusted and works completely automatically. When the power from the transformer power supply is going to the circuit the load will be connected and in the absence of its supply, the load will automatically shift towards the battery. A green LED will glow when the battery will be fully charged. Since the voltage regulator ICs dissipate heat during operations you should use a suitable heatsink. The max output current is 1A, it depends on the transformer used.
Circuit Adjustment
This circuit needs some adjustments before using it. Replace the battery in the circuit with a variable power supply and set its voltage to 14.4V. Adjust the 10K variable resistor until the LED turns on. Now your circuit will be ready to use, remove the variable power supply, and reconnect the battery.
Applications and Uses
- Electronic devices and Projects
- LEDs or Lamps
- Fans
