GW MB10F 0.8A 1000V rectifier bridge

Probe domestic high current needle 150 head diameter 3.0 thread needle high current needle total

Overview:
1 Introduction In single-phase PFC, the efficiency of the whole circuit is limited by the existence of the input rectifier bridge. In order to reduce the loss of the rectifier bridge, many new topologies are proposed. Among these topologies, the bridgeless PFC is simple in structure and control. And it has been widely used [1] [2]. Compared with the traditional Boost PFC topology, DBPFC can improve the efficiency by about 1%~2% because the input rectifier bridge is omitted. However, due to the special position of the inductor, current detection becomes difficult. In this paper, the precision rectifier circuit is used to detect the input current, which has the advantages of simplicity and reliability.

2 DBPFC working mode

Figure 1 DBPFC topology

Figure 1 shows the DBPFC topology. Its operating state can be divided into two phases according to the input voltage. When the input is in the positive half cycle of VL>VN, L1, L2, S1 and D1 form a Boost circuit. When S1 is turned on, it flows through the inductor L1, and the current of L2 increases (direction as shown), and the inductor stores energy. When S1 is turned off, current flows through D1 to supply energy to the load, and the current flowing through inductor L1 and L2 decreases. S2 flows through the reverse current in this phase, and the reverse current flows through the S2 channel or its body diode depends on whether S2 has a drive signal. When the input voltage is in VL

It can be seen from the above analysis that since the DBPFC has no rectifier bridge, the direction of the input voltage and the inductor current are periodically changed. This makes it difficult to detect the input voltage and inductor current required for conventional PFC control.
(Please read the PDF for details)