SMPS (Switched-Mode Power Supply) is an electronic power supply that efficiently converts electrical power using switching regulators. Unlike traditional linear power supplies, SMPS rapidly switches transistors on and off to regulate voltage, resulting in higher efficiency, compact size, and less heat generation.
Key Features of SMPS:
- High Efficiency (70-90%) – Wastes less energy as heat compared to linear power supplies.
- Compact & Lightweight – Uses high-frequency switching, reducing the need for large transformers.
- Wide Input Voltage Range – Can work with varying AC inputs (e.g., 110V–240V).
- Multiple Output Voltages – Provides different DC outputs (e.g., +12V, +5V, -12V).
How SMPS Works:
- Rectification – Converts AC input to DC.
- Switching (Chopping) – High-frequency switching (kHz-MHz) using MOSFETs/BJTs.
- Transformation – Steps voltage up/down via a high-frequency transformer.
- Rectification & Filtering – Converts back to smooth DC output.
- Feedback Control – Adjusts switching to maintain stable voltage.
Types of SMPS:
| Type | Description |
| AC-DC SMPS | Converts AC mains to DC (common in computers). |
| DC-DC SMPS | Converts one DC voltage level to another (used in laptops, cars). |
| Flyback Converter | Used for low-power outputs. |
| Forward Converter | Used for medium- to high-power outputs. |
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