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The recent AFCI threads gave me the idea to take some pics of noise and such that is generated by a few items that I had in my lab. I was mainly interested in laptops and I looked at 3 different ones but the frequency and amplitude was nearly identical so there is just one pic of an IMB Thinkpad. The other laptops I looked at are an HP and a very old Toshiba Satellite running Windows 3.1.

This doohickey monitors the neutral or line and outputs the waveform to be viewed by a scope or spectrum analyzer.

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This heat gun has a brushed motor and could be similar to a vacuum cleaner although the vacuum would most likely have a much higher level of noise. The first waveform is 100mv per division because I wanted to keep it the same as the laptop settings. The second pic is at 1 volt per division and the spikes are still larger than the display.

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Just a little switching power supply similar to a wall wart. The bottom waveform is magnifying one of the noise bursts.

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A "work in progress" switching power supply with not so good AC line filtering also on the 1 volt per division setting. The second pic is a much improved revision of the same model.

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