Starting impact current suppression circuit

Abstract

The invention discloses a starting impact current suppression circuit which comprises a rectifier bridge, a first current-limiting starting circuit, a second current-limiting starting circuit and a Boost circuit. The input end of the rectifier bridge is connected with an alternating current power supply, the output positive end of the rectifier bridge is connected with the input positive end of the first current-limiting starting circuit and the input positive end of the Boost circuit, and the output negative end of the rectifier bridge is connected with the input negative end of the first current-limiting starting circuit and the MOSFET source electrode of the second current-limiting starting circuit; the first output end of the first current-limiting starting circuit is connected with the input end of the second current-limiting starting circuit, and the second output end of the first current-limiting starting circuit is connected with the output negative end of the Boost circuit; the output negative end of the Boost circuit is connected with the drain electrode of the MOSFET of the second current-limiting starting circuit, and the output positive end of the Boost circuit is VOUT. According to the invention, the starting impact current in the power factor correction circuit can be effectively suppressed, the current is limited within 4A, and the reliable operation of the circuit is ensured.

Description

technical field [0001] The invention belongs to the technical field of electronics and electrics, in particular to a starting surge current suppression circuit applied to electronic equipment such as active power factor correction (APFC). Background technique [0002] In order to improve the quality of switching power supply and electromagnetic compatibility of electronic equipment, built-in APFC circuit is generally used to eliminate current harmonics and improve power factor, while the main power circuit of traditional APFC circuit is completed by Boost step-up circuit. It is converted into a DC voltage and input to the Boost circuit, and the Boost circuit boosts the voltage to an output of about 380V. Usually, a large number of filter capacitors (energy storage capacitors in the Boost circuit) are added to the output of the APFC circuit to reduce the output ripple of the subsequent DC / DC converter, so the capacitor must absorb a large amount of current at the moment of po...

AI Technical Summary

Problems solved by technology

[0003] 1. The components of the power input part (such as power switches, fuses, rectifiers, etc.) will be damaged by a large electrical stress, which increases the failure rate of these components and leads to a significant decrease in the mean time between failures (MTBF) of the whole machine

[0004] 2. Generate additional electromagnetic interference, which interferes with other nearby electronic equipment in the form of conduction and radiation, which may cause it to malfunction instantly

[0005] 3. Cause the voltage on the power supply line to drop temporarily, which will have a serious impact on the equipment on the same power supply line, and even cause it to fail

But the disadvantage of this method is: the relay needs a control circuit, and the voltage of the control circuit often affects the circuit complexity

At this time, for the switching power supply of these electrical equipment, it is not necessarily appropriate to use the traditional inrush current suppression circuit.

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