Constant Current and Constant Voltage Converter Based on PWM Modulation

Abstract

The invention belongs to the technical field of power conversion and electronic conversion, and particularly relates to a constant-current constant-voltage converter based on PWM. The constant-current constant-voltage converter comprises a power supply module, a pulse width modulation control chip U1, an auxiliary circuit, a switching tube, an energy-storage capacitor C6 and a sampling resistor. The power supply module is connected with an input end of the pulse width modulation control chip U1, the auxiliary circuit and the sampling resistor, an output end of the auxiliary circuit is connected with the other input end of the pulse width modulation control chip U1, a control end of the pulse width modulation control chip U1 is connected with the switching tube, the other end of the switching tube is connected with the energy-storage capacitor C6, the energy-storage capacitor C6 is connected with the sampling resistor in parallel, and an in-phase input end of the pulse width modulation control chip U1 is connected with the sampling resistor. The constant-current constant-voltage converter is simple in design and actual in effect, the constant-current constant-voltage conversion process is simple, no high-loss devices exist, and efficiency is high; meanwhile, the open-circuit and short-circuit self-protection mechanism is achieved, self-modulation can be achieved under the open-circuit or short-circuit fault condition, and reliability is high.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion, and in particular relates to a constant current and constant voltage converter based on PWM modulation. Background technique [0002] In the prior art, the conversion of constant current into constant voltage generally adopts the method of cascading Zener tubes, which has low output efficiency. Pressure effect, the reliability is low. Especially in the constant current transmission line, the rated output voltage is constant, the greater the transmission current, the higher the requirement for the rated power of the Zener tube, once the Zener tube is damaged, it may cause the failure of the entire transmission line, therefore, in the constant current circuit Among them, such as the power supply system of the submarine observation network based on the constant current power supply method, it does not have high application value. Contents of the invention [0003] The purpose...

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Problems solved by technology

[0002] In the prior art, the conversion of constant current into constant voltage generally adopts the method of cascading Zener tubes, which has low output efficiency. Pressure effect, low reliability

Especially in the constant current transmission line, the rated output voltage is constant, the greater the transmission current, the higher the requirement for the rated power of the Zener tube, once the Zener tube is damaged, it may cause the failure of the entire transmission line, therefore, in the constant current circuit Among them, such as the power supply system of the submarine observation network based on the constant current power supply method, it does not have high application value

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