This article proposes a measurement methodology for extracting input impedance while operating a power device such as a personal computer (PC). Electronic devices such as switched-mode power supply in PC may have different impedances depending on operating conditions. So, the effect of external noise during operation can be predicted through impedance extraction. Since it uses a type of inductive coupling, the conventional method of extracting impedance during operation using current probes makes measurement challenging at low frequencies because the signal is attenuated due to the decrease in induced voltage when the frequency decreases. As a solution, this article proposes a methodology that amplifies the signal by increasing the number of turns on the probes. Using the proposed methodology, it is possible to extract the impedance of a power device by adjusting the number of turns according to the frequency. Calculation of the number of turns appropriate for an increased signal was verified through experiments. The proposed methodology makes it possible to extract the impedance of a device during operation over broadband, from 20 kHz to 100 MHz. It can be applied for various fields, such as electromagnetic pulse protection and electromagnetic interference filter design in the future.

中文翻译：

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使用双电流探头法提取个人计算机运行期间低频输入阻抗的方法

本文提出了一种在操作个人计算机 (PC) 等电源设备时提取输入阻抗的测量方法。电子设备（例如 PC 中的开关电源）可能会根据工作条件而具有不同的阻抗。因此，可以通过阻抗提取来预测运行期间外部噪声的影响。由于它使用一种电感耦合，因此使用电流探头在工作期间提取阻抗的传统方法使得低频测量具有挑战性，因为当频率降低时，由于感应电压的降低，信号会衰减。作为解决方案，本文提出了一种通过增加探头匝数来放大信号的方法。使用所提出的方法，可以通过根据频率调整匝数来提取功率器件的阻抗。通过实验验证了适合增加信号的匝数的计算。所提出的方法可以提取设备在宽带（20 kHz 至 100 MHz）运行期间的阻抗。未来可应用于电磁脉冲防护、电磁干扰滤波器设计等各个领域。