Switch Mode Power Supply

“SWITCH-MODE POWER SUPPLY” is work of four types.

1.     ac-dc conversion called rectification

2.     ac-ac conversion ,

3.     dc-ac conversion and

4.     dc-dc conversion.

1.     A switch mode power dc output voltage using a circuit known as Buck Converter or Step-Down SMPS,

2.     step up an unregulated dc input voltage to produce a regulated dc output voltage using a circuitknown as Boost Converter or Step-Up SMPS,

3.     step up or step down an unregulated dc input voltage to produce a regulated dc output voltage ,

4.     invert the input dc voltage using usually a circuit such as the Cuk converter, and

5.     produce multiple dc outputs using a circuit such as the fly-back converter.

A switch mode power supply is a widely used circuit nowadays and it is used in a system such as a computer, television  receiver, battery charger etc. The switching frequency is usually above 20 kHz, so that the noise produced by it is above the audio range. It is also used to provide a variable dc voltage to armature of a dc motor in a variable speed drive. It is used in a high-frequency unity-power factor circuit.