Snubber Circuit for Full Bridge Converter
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
This article describes a bridge-type snubber for a full bridge converter, providing reduced power dissipation and switch turn-on losses. The snubber is shown in Fig. 1. It comprises clamp diodes CR10-CR13, C2, C3 and R1. The rest of the circuit is a conventional full bridge converter. Operation of the snubber will be described with reference to Fig. 2, which depicts the waveforms of VP and IP with time. At the end of Ton(1), switches S1 and S4 are on, and are conducting the transformer T1 primary current ip . This current continues to flow after turn-off of the switches due to the leakage energy of T1. At this time, assuming that C2 = C3, and assuming that the time constant of the RC network R1-C2-C3 is short compared to the on time, C2 and C3 are charged to a voltage of 1/2 VB .