Push-pull circuit of DC/DC (Direct Current/Direct Current) part

Abstract

The invention suitable for the field of electronic circuit provides a push-pull circuit of a DC / DC (Direct Current / Direct Current) part, which comprises a boosting transformer and a primary switch tube as well as a voltage doubling rectifying circuit connected with the output ends of the boosting transformer and the primary switch tube; the output end of the voltage doubling rectifying circuit is connected with an output filter and energy storage circuit and a current detection unit; the output end of the filter and energy storage circuit is connected with a voltage / detection unit; the output ends of the current detection unit and the voltage / detection unit are both connected with a multi-signal feedback sampling unit; the multi-signal feedback sampling unit is connected to a controller; the controller is provided with a storage device and a communication interface, and the output end of the controller is connected with a driver; the driver is connected with the boosting transformer and the primary switch tube; and the input end of the controller is also connected with an input voltage detection unit and auxiliary power. In this way, output performance index, power conversion efficiency and temperature rise performance index of the digital push-pull circuit are improved.

Description

technical field [0001] The invention belongs to the field of electronic circuits, in particular to a push-pull circuit of a DC / DC part. Background technique [0002] The DC / DC part of the low-power UPS power supply generally adopts a push-pull topology, which converts the lower battery voltage into a bus voltage of about 400V as the input of the subsequent inverter. If only the voltage loop is used to control the output voltage of the push-pull converter, because the load is an inverter, the input current is a low-frequency current fluctuation with twice the inverter frequency. This fluctuation will cause the voltage and current stress of the primary switching tube to be too large, reduce the efficiency of the converter, and increase the temperature rise. In order to avoid these disadvantages, it is necessary to increase the current loop so that the input current is direct current. [0003] The current loop sampling of the existing push-pull converter is all on the primary...

AI Technical Summary

Problems solved by technology

[0008] 1. Resistive sampling has a large loss, complex structure, difficult PCB wiring, and high cost, and is only suitable for occasions with small input currents;

[0009] 2. The Hall current sensor type can meet the current sampling requirements, but the cost is too high

However, it requires a magnetic reset, and the circuit fails when it is close to the full duty cycle, and the current sampling cannot be realized in a full range.

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