具备参数检测及显示功能的低频功率放大器的设计

Design of Low-frequency Power Amplifier with Parameter Detection and Display Function

本设计的低频功率放大器基于甲乙类互补对称功率放大电路原理,采用集成运放NE5532构成三级前置放大电路有效放大弱信号.末级功放管采用大功率MOS晶体管IRF9640和IRF640对管,构成推挽式输出电路,有效减少非线性失真.采用集成滤波器MAX261消除工频信号干扰,放大器输出功率、直流电源的供给功率和整机效率等参数的检测及显示由单片机AT89C51控制实现,另外还针对本系统制做了自带的直流电源,可保证对负载的功率输出.

Based on Class-AB complementary symmetry power amplifier circuit theory, the designed low- frequency power amplifier using an integrated operational amplifier NE5532 as 3-level preamplifier circuit to amplify the weak signal effectively. The last stage power amplifier tube using high-power MOS transistors IRF9 640 and IRF 640 right tube constitutes a push-pull output circuit and can reduce the non-linear distortion effectively. An integrated filter MAX 261 was used to eliminate frequency signal interference. The amplifier output power, the supply power of DC power, efficiency of detection and display of the machine were controlled by the microcontroller AT89C51. In addition, the built-in DC power was made for the system to ensure the power output of the load.