Návrh laboratórneho napájacieho zdroja

Abstract

This bachelor's thesis deals with the design, simulation and implementation of a laboratory switched-mode power supply with adjustable output voltage 0–30 V and output current 0–3 A powered from 230 V AC mains. Based on a review of available switching converter topologies, the Flyback topology was selected with the UC3842N controller from Texas Instruments operating in current mode control. The thesis includes a theoretical analysis of linear and switched-mode power supplies, an analysis of DC-DC converter topologies and justification of the Flyback topology selection. The design section covers the calculation of high-frequency transformer parameters with an ETD34 core, the CV and CC control loop with fail-safe feedback implemented using a PC817 optocoupler. Circuit simulation was performed in OrCAD PSpice, where the linearity of the regulation, the function of the snubber circuit and the fail-safe mechanism were verified. Physical implementation was carried out on a printed circuit board designed in Autodesk Fusion 360. Functional verification of the constructed prototype confirmed compliance with all requirements – output voltage range 0–30.05 V, output current 0–2.95 A, switching frequency 93.73 kHz and efficiency of 63.2 % at an output power of 85.6 W.