Coil whine of (meanwell) SMPS and also graphics cards.

[rock soderstrom]

I am currently researching the meanwell offer for suitable (dual) SMPS for a project and have read quite a few reviews on Amazon that report disturbing coil whine. This also seems to be related to the load, less load seems to go hand in hand with more whine.

What are your experiences?

Additional question: My Geforce graphics card has also developed an annoying coil whine over time. Can anything be done against it?

 

[mkiijam]

We used to solve coil whine on CRT TV's with dipping them in varnish or from spray can.

 

[JohnRoberts]

This may just be coincidental but about 20 years ago I inherited a design to consult upon (1RU DSP). It had a clever two voltage output DC to DC switching power supply. Instead of the typical one output voltage single inductor design, it used a switching transformer to generate two different regulated output voltages. For whatever reason it had an annoying hum/buzz, I tried many tweaks to the circuit but nothing got it quiet. I searched for an alternate source for the HF switching transformer with zero luck. I redesigned the PS (that I inherited) to be a single output switcher, with a 3 terminal regulator to generate the second lower voltage. It was less efficient but dead silent.

The quiet single inductor was potted, the buzzy transformer not and made too much noise to use in a premium rack unit.

JR

 

[GeorgeToledo]

I’d probably take it out and see how the thermal paste has held up. If it looks like it is degrading I would put some new paste on it.

There are probably other things that could be done but that’s my first thought.

 

[k brown]

Just wondering if thermally conductive pads might provide more damping than paste.

 

[rock soderstrom]

Thanks for the tips guys, I'll try that out on my graphics card when I get back from vacation.

As for the Meanwell power supplies, I was surprised after reading the reviews on Amazon that some of them have the problem right out of the box, whether single or dual solution.

That's why I was surprised because some people here seem to be using this successfully in studio equipment and it would certainly be considered particularly annoying here.

But there don't seem to be any problems with that, at least nobody is talking about it.

In the Amazon reviews, some people found the Meanwell coil whine too annoying even when used (behind the interior paneling) as a room lighting PSU...

I'll buy some Meanwell modules when I get back and see if it's really a problem, I hope not. My recent experiment with SMPS in audio gear has been very promising, I'd like to expand on that.

 

[k brown]

"Meanwell Coil Whine" - great name for a band.

 

[rock soderstrom]

"Meanwell Coil Whine" - great name for a band.

Yes for a US-Japanese-German avant-garde band with 6 guitars, no bass and two drummers. But the main instrument is a Coil Whinophone!

 

[mrclunk]

We used to solve coil whine on CRT TV's with dipping them in varnish or from spray can.

Me too, yacht varnish, warm part up in oven before dipping.

 

[rock soderstrom]

We used to solve coil whine on CRT TV's with dipping them in varnish or from spray can.

This sounds like a good plan for larger coils, perhaps it can also be applied to the rather small SMT(?) coils of a graphics card. I'll have to take a closer look at which components make the sound.

 

[jp8]

Also, keep an eye out for noisy MLCCs.

https://www.ti.com/lit/pdf/ssztb09