How does a switching power supply work?

A switching power supply converts AC voltage to DC voltage using high-frequency switching.

Switching power supplies are used to convert AC voltage to DC voltage. They work by first rectifying the AC voltage to a high-voltage DC voltage. This voltage is then fed into a high-frequency oscillator that switches the voltage on and off at a high frequency. The resulting waveform is a square wave with a duty cycle that determines the average voltage output. This waveform is then filtered to remove the high-frequency components, leaving only the desired DC voltage.

The high-frequency switching allows for smaller and lighter components to be used in the power supply, making it more efficient and cost-effective. The switching frequency is typically in the range of tens to hundreds of kilohertz.

Switching power supplies can be designed to be either step-up (boost) or step-down (buck) converters. A step-up converter increases the voltage output, while a step-down converter decreases the voltage output. Both types of converters use inductors and capacitors to store and release energy, allowing for efficient voltage conversion.

Overall, switching power supplies are a popular choice for electronic devices due to their efficiency, small size, and low cost.