Constant voltage and constant current control circuit

Abstract

The invention discloses a constant voltage and constant current control circuit and a constant voltage and constant current switching compensation method. The method includes utilizing a constant current error amplifier (CCEA) to generate a constant current signal, utilizing a constant voltage error amplifier (CVEA) to generate a constant voltage signal, receiving the constant current signal and the constant voltage signal to control a controlled system, compensating current extracted by the CCEA from the CVEA in a period that the controlled system works in a constant voltage status and output current is approximate to a constant current value, and compensating current provided by the CVEA to the CCEA in a period that the controlled system works in a constant current status and output voltage is approximate to a constant voltage value. The constant voltage and constant current control circuit has the advantages that starting from basic reasons for interference in a switching period from the CCEA to the CVEA, output of the CCEA and the CVEA in a constant voltage and constant current switching period is compensated, so that a current range of non-constant voltage and non-constant current in the constant voltage and constant current switching period is eliminated, and the circuit can realize lossless switching between constant voltage and constant current.

Description

Technical field [0001] The invention relates to a constant voltage and constant current circuit, in particular to a constant voltage and constant current control circuit and a constant voltage and constant current switching compensation method. Background technique [0002] In the control system, constant voltage and constant current control is achieved by controlling the duty cycle. figure 1 Shown is an existing specific structure, only this specific method is used as an example for illustration, such as figure 1 As shown, the main modules of the circuit include: a constant current error amplifier (CCEA) (constant current error amplifier, CCEA), a constant voltage amplifier 102 (constant voltage error amplifier, CVEA), a state controller 103, etc. Among them, CVEA102 works when the controlled system is working in a constant voltage state to control the constant output voltage, and CCEA101 works when the controlled system is working in a constant current state to control the const...

AI Technical Summary

Problems solved by technology

[0018] The object of the present invention is to provide a constant voltage and constant current control circuit and a constant voltage and constant current switching compensation method to solve the problem of the constant voltage and constant current control circuit in the prior art during the constant voltage and constant current switching process. In the interval, the current is neither constant voltage nor constant current

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