通过个人电脑声卡实现音频频率的简单同步检测。

Simple synchronic detection at audio frequencies through a PC sound card.

作者信息

González Martín G, Santiago Guillermo D, Slezak Verónica B, Peuriot Alejandro L

机构信息

Laboratorio Láser, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, 1063 Buenos Aires, Argentina.

出版信息

Rev Sci Instrum. 2007 May;78(5):055108. doi: 10.1063/1.2740063.

DOI:10.1063/1.2740063

PMID:17552861

Abstract

We present a simple personal computer based, synchronic detection system that emulates a lock-in amplifier at audio frequencies. The inputs of the sound card are used to acquire two sets of samples: the one to be measured, previously preamplified, and the reference. From the last one, two "quasiorthogonal" signals are derived to perform dual-phase detection. The procedure is fast and compares favorably with a benchtop lock-in amplifier. In the band from 100 Hz to 20 kHz we obtained average amplitude and phase errors below 1% and 0.1 degrees, respectively.

摘要

我们展示了一种基于个人计算机的简单同步检测系统，该系统可在音频频率下模拟锁相放大器。声卡的输入用于采集两组样本：一组是经过预放大的待测样本，另一组是参考样本。从参考样本中导出两个“准正交”信号以进行双相检测。该过程快速，与台式锁相放大器相比具有优势。在100 Hz至20 kHz的频段内，我们分别获得了平均幅度误差低于1%和相位误差低于0.1度的结果。