This is a simple and easy to make 12V 5A Linear Power Supply Circuit.
It uses transformer, bridge rectifier, filter capacitor, control transistor and regulator IC.
Circuit gives clean 12V output.
It is good for LED strips, small radios, car stereo tests, chargers and hobby projects.
Circuit is easy to build and its parts are common.
Circuit Working:
Parts List:
| Component | Specification | Quantity |
|---|---|---|
| Resistors | 50Ω, 0.12Ω 5W | 1 each |
| Capacitors | Electrolytic 4700uF 50V, 470uF 25V | 1 each |
| Semiconductors | IC 7812 voltage regulator | 1 |
| Power Transistor 2N3792 | 1 | |
| Driver Transistor 2N6049 | 1 | |
| Diodes Bridge rectifier 6A10 | 4 | |
| Transformer 220V AC ,12V 4A output | 1 | |
| Fuse 1A or 2A | 1 | |
| On/Off switch | 1 | |
| Load 12V up to 5A | 1 |
AC mains goes to transformer and the transformer steps down AC to around 15V.
Bridge rectifier converts AC to DC and big capacitor C1 smooth the ripple.
Transistor Q1 and Q2 work like pass transistor and driver transistor.
Q1 gives current boost up to 5A.
IC 7812 hold voltage at 12V stable.
R1 and R2 help current sharing and drive.
Output capacitor C2 keep output stable.
Fuse and switch protect the circuit.
Load takes the output current from the power supply.
How to Build:
To build a 12V 5A Linear Power Supply Circuit follow the below connection steps:
- Take all parts same like circuit diagram.
- Transformer primary wires go to AC mains by switch and fuse.
- Transformer secondary wires go to bridge rectifier AC pins.
- Bridge rectifier plus pin go to big capacitor positive.
- Bridge rectifier minus pin go to ground.
- Q2 2N6049 base connect to Q1 emitter and resistor R2.
- Q2 collector go to Q1 base and also go to IC input pin.
- Q2 emitter connect to resistor R1 and R2 joint point.
- Q1 2N3792 base connect to IC input pin.
- Q1 emitter go to Q2 base.
- Q1 collector connect between IC output pin and capacitor C2.
- IC 7812 pin1 is input, connect to Q1 base side.
- Pin2 is ground, connect to circuit ground.
- Pin3 is output, go to load positive.
- Output capacitor C2 connect between IC output and ground.
- All ground points join together in whole circuit.
Conclusion:
This 12V 5A Linear Power Supply Circuit gives strong and stable 12V at 5A.
Parts are cheap and easy and need big heat sink because power loss is high.
Good for learning linear supply working.
Easy for hobby builders and repair work.
References:
Is 12 Volt 5A power supply too much for Arduino Uno? HELP
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