摘要
本设计为根据输入信号及周围的环境噪声幅度自动调节音量的自动增益控制音量放大器。整体设计以STC12系列单片机为控制器,通过单片机内部采样得到有效信号,NE5532(高性能低噪声双运算放大器(双运放)集成电路)为关键器件,NE5532产生的放大倍数还需要电路中的数字电位器来控制,改变数字电位器的阻值可以改变放大倍数,自动增益功能由此操作完成,从而控制最终的输出信号。双运放集成电路需从电路中的音频信号源端口接入,且为100 Hz^10 k Hz信号,用以驱动5 W/8Ω的喇叭(或600Ω负载)。当输入端给定信号在10 m V^5 V之间时,测得示波器显示输出电压始终稳定在2 V±0.2 V内。其幅度大小和频率高低在示波器上可以同时确认。并允许在1 V^3 V范围内对放大器输出电压进行步进式的幅度调节且步距档位为每档0.2 V,所有输出结果由LCD12864液晶显示屏显示。
This article makes a design of automatic gain control volume amplifier which automatically adjusts the volume based on the input signal and the surrounding environment noise amplitude. The overall design takes the STC12 series single chip microcomputer as the controller, through the internal sampling of single chip microcomputer to get the effective signal. The NE5532 [ high-performance low noise dual operational amplifier （double op-amp） integrated circuit ] is used as the core amplifier, by changing the resistance of potentiometer to change the magnification of sampling signal and achieve the function of the control gain, finally to control the output. The amplifier inputs thel00 Hz to 10 kHz signal from the audio source device drive the 5 W / 8 Ω speakers （ or 600 load）. When the input voltage signal amplitude value is changed between 10 mV- 5V, the default value of output voltage is within 2 V ＋/-0.2 V, at the same time it can display the size and frequency. All output result is displayed by LCD12864.
出处
《山西电子技术》
2016年第6期29-31,共3页
Shanxi Electronic Technology
