RFI or EMI can be caused by sources such as TV or radio broadcast signals or it can be caused by impulse sources, as in the case of high voltage arcing (see Figure 3-5).

• RFI和EMI可能由诸如电视或无线电广播等信号源引起，也可能由脉冲信号源引起，就象高压电弧的情况那样（见图3-5）。