Convert 220V AC to 12V DC Without Transformer | Simple Capacitor Power Supply
[Sekhohub.online]
Overview:
This simple and compact circuit converts 220V AC mains voltage directly into 12V DC using a capacitive dropper approach. It’s a low-cost solution for powering small electronic devices, especially where current demands are minimal.
Materials for the Project
| Component | Specification | Function |
|---|---|---|
| Capacitors | 2x 225J 400V (2.2µF) | Drop AC voltage using reactance |
| Resistors | 2x 1MΩ | Bleeder resistors (discharge capacitors safely when unplugged) |
| Diodes | 1x 1N4007 | Rectification (convert AC to DC) |
| Electrolytic Cap | 1000 µF 25 V | Smooths the rectified DC output |
| Zener Diode | 12V | Regulates and clamps the output voltage to 12V |
| AC Plug | 220V input | Power supply input from AC mains |
⚡How It Works:
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AC Input (220V) is passed through two high-voltage non-polar capacitors (225J400V), which drop the voltage by capacitive reactance.
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1MΩ resistors are added in parallel to safely discharge the capacitors.
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The reduced voltage is rectified using 1N4007 diodes.
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A 1000 µF capacitor filters the voltage into a smoother DC.
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A 12V Zener diode ensures the final DC output stays regulated at around 12 volts.
⚠️Warning:
This circuit is non-isolated and directly connected to live 220V AC. Do not touch any component while it’s powered.
Always enclose it in a well-insulated box. This design is suitable for low-current applications only (like sensors, indicators, etc.).
✅ Applications:
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LED Drivers
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Small sensors
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DIY alarm circuits
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Timers
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Low-power 12V logic systems
Conclusion:
This is a great project for understanding how capacitive power supplies work. It’s efficient and cheap—but safety is critical.