Charging system on the basis of secondary control and secondary control device thereof

Abstract

The present invention discloses a charging system on the basis of secondary control and a secondary control device thereof. The charging system comprises: a transformer; a rectifying device; a secondary rectification switch tube and a secondary synchronous rectification auxiliary chip which is used for controlling the start and the stop of the secondary rectification switch tube and allowing a suddenly changed voltage to be enlarged by controlling the secondary rectification switch tube when the changing of the peak current of the secondary rectification switch tube is detected, a line drop compensating signal being generated when the enlarged suddenly changed voltage is fed back to an auxiliary winding; a primary control chip and a primary switch tube, the primary control chip being configured to generate a line drop compensating current when the line drop compensating signal is acquired and being configured to control the primary switch tube to compensate the output voltage of the system according to the line drop compensating current and the voltage and the feedback voltage detected at the voltage detection end. The charging system on the basis of secondary control is able to realize the compensation of the output voltage of the charging system through real time detection of the output current of the charging system on the basis of the secondary control, therefore the precision of the output voltage is greatly improved.

Description

technical field [0001] The invention relates to the technical field of chargers, in particular to a charging system based on secondary control and a secondary control device for the charging system based on secondary control. Background technique [0002] With the gradual increase of the battery capacity of the mobile phone, the output current of the charger becomes larger and larger, and the line voltage drop of the output line cannot be ignored, which greatly affects the output voltage accuracy of the charger. Therefore, it is necessary to increase the output line voltage drop compensation function in the charger. [0003] Such as figure 1 As shown, the current mainstream solution is that the primary control chip IC detects the size of the output load, mainly by determining the change of the output voltage to determine the change of the output load, and then generates the output line voltage drop compensation signal after being amplified by the voltage amplifier in the ch...

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Problems solved by technology

[0004] However, since the operating frequency of the chip IC differs greatly when the charger is no-load and full-load, it will cause a large difference in the AC gain of the voltage amplifier when it is no-load and full-load, and finally leads to the deterioration of the output voltage linearity of the voltage amplifier. Therefore, the output line voltage drop compensation signal generated by the output of the voltage comparator also has the problem of poor linearity. The output voltage has high consistency across the entire load segment, and it is difficult to achieve high voltage accuracy

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