Explaining the of operation of an LLC current resonant power supply
I. Introduction of technology LLC current resonant power supply
In nowadays, in many household device circuits need a power supply has features like small size, high efficiency, lower noise. And to answer for that demands Fuji electric company has developed LLC current resonant converter. In this articel we will explain what a LLC current resonant converter is and how it works. A LLC current converter can provide 100W -500W power, and it can prevent from short circuit of Mosfet problem, which is safer.
II. What is the circuit design of LLC current resonant power supply
Below figure 1 is a basic design circuit of the LLC current resonant converter. It has two MOSFETs Q1 Q2, Cr resonant capacitor, Np winding of T pulse transformer at the primary side. On the secondary side of the T transformer, it has Np winding, D1 D2 diodes to convert DC output voltage, and a C0 capacitor to make output DC voltage flat.
We also meet an equivalent design for the LLC current resonant converter in the figure where Lr1 and Lr2 are for leakage inductance and Lm is for magnetizing inductance.
III. Basic operation of LLC current resonant power supply