EEVblog 1607 - PSU Switching Noise Reduction via Vibration

[EEVblog]

Physically vibrating your power supply at a sub harmonic of your PSU switching frequency can potentially lower your system noise. A practical demonstration.

[isometrik]

That effect is known as the fishbowl effect in the literature.

 

[Xena E]

What a Cock

Gave me a laugh though... keep it up! 

 

[tszaboo]

You have to be really careful to avoid the resonance cascade. Especially if you are working with the Anti-Mass Spectrometer.

[.RC.]

Easier to just go full Star Trek and change the polarity of the ODN junctions.   

[golden_labels]

It’s a well known among IT experts method of reducing fan and disks vibration. Electrolyte in PSU’s smoothing capacitors crystalizes and the capacitor starts exhibiting a dip in conductance at specific frequencies. In general it’s not a problem and, where it is, manufacturers employ spectrum spreading (you may recall this advertised on your old mobos). But it remains a problem in devices which rotate at fixed speeds, like computer fans and HDDs. Disks are particularly vulnerable, because their high inertia keeps the spinning frequency constant. Hitting the computer case in the right way produces enough of higher harmonics to make crystals in capacitors to break down, restoring unrestricted flow of energy.

Dave is wrong on one thing: you can deliver MHz range vibrations. This is what medical ultrasonography uses. The reason it doesn’t work for reducing spikes is the wavelength. Sound wave at 10 Mhz has wavelength of 1 mil, that is less than a thickness of US dollar bill. The wave passes through the capacitors and inductors as if they weren’t there, instead of being absorbed.

[pdenisowski]

This was actually the subject of an IEEE paper

[EEVblog]

This was actually the subject of an IEEE paper

That must be the one I read 

[SiliconWizard]

Excellent! 

[SiliconWizard]

This was actually the subject of an IEEE paper

That must be the one I read 

Well, that's the whole concept of acoustic black holes.

[EEVblog]

Dave is wrong on one thing: you can deliver MHz range vibrations. This is what medical ultrasonography uses. The reason it doesn’t work for reducing spikes is the wavelength. Sound wave at 10 Mhz has wavelength of 1 mil, that is less than a thickness of US dollar bill. The wave passes through the capacitors and inductors as if they weren’t there, instead of being absorbed.

Correct. At Thales we used to do MHz range phased array sonar, it just passes right through.

[egonotto]

Hello,

it is fitting that the authors of the article are called First and April in Polish.

Best regards
egonotto

[Keri Szafir]

...from the Beaver University! Pet that beaver and try once again just to see if it was not a Fluke.
I'm Polish and haven't even noticed, LOL.

[Ranayna]

I have to admit: You got me
I know that you always post these videos. Yesterday i actually thought that i might have missed it due to the Algorithm.
Now i read this thread, and yet again i had to realize: Damn, you Australians are early I did not miss the video, it totally flew over my head.

But while your earlier videos were obvious, this got me...

[strawberry]

oscillators may run off