This 5V 3A Linear Power Supply Circuit is very simple for one to give it a try, as it uses only LM323K IC and few more parts which are easily available; also, it gives 5V fixed output and can handle load up to 3A.
Circuit Working:

Parts List:
| Components | Values | Quantity |
|---|---|---|
| Capacitors | Electrolytic 4700uF 25V, 470uF 25V | 1 each |
| Ceramic 0.1uF | 1 | |
| Semiconductors | Voltage Regulator IC LM323K (5V 3A) | 1 |
| Bridge Rectifier 1N5408 3A each 200V | 1 | |
| Transformer Primary AC input 230V / Secondary 9V at 3A | 1 | |
| Fuse 1 Amp | 1 |
To begin with, the circuit have few parts and is easy to build.
First, transformer change AC main voltage 230V to AC 9V and bridge diode change AC to DC; then capacitor C1 make DC smooth.
After that, IC LM323K give steady 5V output and then this IC also protect from short circuit, overcurrent and overheating.
How to Build:
To build a 5V 3A Linear Power Supply Circuit follow the below steps:
- First, collect all parts as shown in circuit diagram.
- Next, input pin goes to bridge +.
- Then ground pin goes 0V.
- After that, output pin goes 5V 3A line.
- Also, feed DC to pin1 goes with big capacitor C1.
- Now pin 2 join C2 and C3 capacitors and
- Further, bridge one end goes ground and other 2 bridge pins go transformer secondary.
- Finally, transformer primary end go to AC input with fuse.
Conclusion:
Overall, this circuit is simple and reliable and it gives stable 5V for many electronic projects, also parts are easy to find and cheap.
In addition, circuit is good for hobby, testing bench and small microprocessor systems.