Variable Switching Power Supply Using LM2576 [Buck Converter, CC-CV]

by sam_moshiri in Circuits > Electronics

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Variable Switching Power Supply Using LM2576 [Buck Converter, CC-CV]

How to build an adjustable switching power supply using LM2576 [Buck Converter, CC-CV]

Switching power supplies are known for high efficiency. An adjustable voltage/current supply is an interesting tool, which can be used in many applications such as a Lithium-ion/Lead-acid/NiCD-NiMH battery charger or a standalone power supply. In this article, we will learn to build a variable step-down buck converter using the popular LM2576-Adj chip.

Features

  • Cheap and easy to build and use
  • Constant current and constant voltage adjustment [CC, CV] capability
  • 1.2V to 25V and 25mA to 3A controlling range
  • Easy to adjust the parameters (optimum use of variable resistors to control the voltage and current)
  • The design follows the EMC rules
  • It is easy to mount a heatsink on the LM2576
  • It uses a real shunt resistor (not a PCB track) to sense the current

Schematic

FIG1-How to build an adjustable switching power supply using LM2576 [Buck Converter, CC-CV].jpg

PCB Layout

FIG2-How to build an adjustable switching power supply using LM2576 [Buck Converter, CC-CV].jpg

A 3D/Real View of the Asemblde PCB Board

FIG4-How to build an adjustable switching power supply using LM2576 [Buck Converter, CC-CV].jpg
FIG5-How to build an adjustable switching power supply using LM2576 [Buck Converter, CC-CV].JPG

Component Libraries (SamacSys)

FIG3-How to build an adjustable switching power supply using LM2576 [Buck Converter, CC-CV].jpg

References