Charging system based on secondary control and its secondary control device

Abstract

The invention discloses a charging system based on secondary control, comprising: a transformer; a rectification device; a secondary rectification switch tube and a secondary synchronous rectification auxiliary chip, and the secondary synchronous rectification auxiliary chip controls the opening and closing of the secondary rectification switch tube , and control the secondary rectifier switch tube according to the received transmission signal of the charging interface to adjust the sudden voltage generated at both ends of the secondary winding, and generate an output voltage switching signal when the adjusted sudden voltage is fed back to the auxiliary winding; the primary The control chip and the primary switch tube, the primary control chip generates a gate signal when it collects the output voltage switching signal, and controls the primary switch tube according to the gate signal, the voltage detected by the voltage detection terminal and the feedback voltage of the voltage feedback terminal to adjust the system output voltage and output current. The charging system can intelligently change the charging output specification according to the load. The invention also discloses a secondary control device of the charging system based on secondary control.

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 development of science and technology, all kinds of electronic products can be seen at any time in people's daily life, and become an indispensable thing in life, but how to charge these electronic products has also become a matter of increasing concern in the industry. However, different electronic products have different charging specifications, some require 5V, and some require 9V and 12V. [0003] Such as figure 1 As shown, the current mainstream solution is to obtain the transmission signal from the terminal through the D line in the USB interface, and then use a decoding chip to selectively turn on the corresponding MOS transistor to change the ratio of the voltage dividing resistor to achieve different outp...

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Problems solved by technology

[0004] However, the disadvantages of this scheme are: 1. Several MOS transistors are required to change different output voltages, and the secondary control scheme needs to cooperate with optocoupler and controllable device TL431, and the overall cost is relatively high; 2. The only change is The output voltage and output current do not change accordingly, which will cause the phenomenon that the low-power load is charged with a large current, which will affect the life of the battery at the load terminal

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