If you want a 12V power supply that can give up to 1 amp because store-bought options too expensive? This is the post that can build your own at home with basic components and not much cost! This is for others, so they could also make their own reliable power supply. It’s a fun and rewarding DIY project for anyone interested in electronics!
Step 1: Necessary Items
| Material | Quantity | Notes |
| Veroboard | 1 | Small size, enough to fit your components |
| 1N4001 diodes | 4 | Used for rectification |
| LM7812 voltage regulator | 1 | Regulates output voltage to 12V |
| Transformer | 1 | Output: 14–35V AC, current: 100mA–1A |
| Capacitor (1000–4700µF) | 1 | Used for filtering |
| Capacitor (1µF) | 1 | Provides additional filtering |
| Capacitor (100nF) | 2 | Helps reduce noise |
| Jumper wires | As needed | Plain wires are sufficient |
| Heatsink | 1 | Needed if the regulator will supply 1A or near its maximum load. |
| LED (optional) | 1 | For indicating the power supply is working (if desired) |
Tools
Here are the tools required:
- Soldering iron
- Wire cutters
- Wire strippers
- Track cutter
- Hot glue
- Any other small tools that may help.
Step 3: Schema and Guidelines
In a 5V power supply, one should replace the LM7812 regulator with an LM7805.
If you’re drawing up to 1 amp, you’ll need a heatsink for the regulator to prevent it from overheating. For lower currents (under 500mA), a heatsink is optional, though the regulator may feel warm.
Add an LED indicator that will show if the power supply is functioning (optional).
Here’s the schematic you will follow to make it. If you do not know how to read schematics, there are lots of online tutorials you can find.
Step 4: Assembly
Follow the schematic and solder all the components to the veroboard.
Ensure your solder joints are solid, and there is no solder bridge or short circuit.
Step 5: Testing
- Using a multimeter, check the output voltage and check for solder bridges.
- Place the power supply in a plastic box or similar and test it for electrical shock.
- Warning: Avoid using a supply with mains voltage exposed-this is very dangerous, and dangerous injury is often caused by it. For reference, my output of the power supply is 11.73V—not perfect, but good enough for my needs.
Conclusion:
You’ve built a cheap and functioning 12V power supply! Use it as you need to, but always provide proper protection when using it.