Current limiting power amplification driving circuit for power line carrier communication

Abstract

The invention relates to a current limiting power amplification driving circuit for power line carrier communication, which is used for realizing power amplification of a power line carrier sending signal and is coupled to a power line. The current limiting power amplification driving circuit is characterized by comprising a current limiting block input circuit, a first-stage bias amplifying circuit, a second-stage current limiting amplifying circuit, a third-stage power driving circuit, a feedback circuit and a power line carrier signal coupling circuit. The current limiting block input circuit in the circuit realizes current limiting protection over the power amplifier current input stage; the base voltage lower limit of a triode Q4 in the third-stage power driving circuit is improved by the second-stage current limiting amplifying circuit, and the maximum base current of the triode Q4 is limited, so that the power amplifier circuit is prevented from entering a working dead zone where the Q4 is connected all the time; the second-stage current limiting amplifying circuit has a current limiting effect on the third-stage power driving circuit, so that the triode therein is prevented from being damaged due to overload; and the circuit is suitable for a variable carrier load impedance condition in an actual application field.

Description

technical field [0001] The invention relates to a current-limiting power amplification drive circuit for power line carrier communication, which belongs to the technical field of power line carrier communication. Background technique [0002] Because power line carrier communication has the characteristics of no need to set up additional communication lines, automatic adaptation to user distribution, low cost, and easy networking, power line carrier communication is currently the preferred solution for low-voltage automatic meter reading communication, and it is also the main method of current distribution network communication. In order to achieve high-quality power line carrier communication effect, the design of the power amplifier drive circuit for the signal sent by power line carrier communication is one of the important issues in the research of power line carrier communication technology. The power amplifier circuit of the power line carrier communication signal need...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to propose a current-limiting power amplification drive circuit for power line carrier communication, which will solve the problems of the existing power amplification drive circuit for power line carrier communication, realize the current limitation of the input, and avoid entering the working dead zone, Realize the current limiting protection of the final triode drive, avoiding the overload damage of the triode caused by the small carrier load impedance in practical applications

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