people have aksed me
what am i up to
am I sure it's the coils
are these "torroidal chokes" or transformers
I have to take into account the heat these things produce..
why not get ac dc adaptors ..
Well.. I want a fanless computer, it's an ideal, but i'd like it. And
I don't like things that make a high pitched whining noise either.
Some years ago the only option was a VIA machine. Now, there are
fanless components, but i'm not convinced how long a regular MBRD
would last fanless. There are "voltage regulators" on the mbrd that
need cooling, i'd need a heatsink for them. And i'm not sure how
reliable the fanless power uspplies are.
A VIA system is cheap. I built one years ago anyway. But there was
one problem.
The Fanless power supply card made a high pitched noise. Just like
some TVs do. Just like some cheap ACDC adaptors do. That power supply
card was made by a company called Morex. There was another competitor
that made one but it had the same problem. I contacted Morex, and
they said it was because the transformers were not made with ferrite.
And to do so would be more expensive and they don't do it.
I have no electronics background. But getting some liquid epoxy and
filling up a bagel shaped transformer, or thing that looks like a
transformer. That I understand! Epoxy I think conducts heat.
The morex power supply card (I bought it from linitx), has gone
walkies, and the newer versions are probably not the same. THey may
whine, they may not whine. Most shops they can't hear the whine. If
they could then they I doubt they'd be able to use it!!
I did buy a cheap AC-DC adaptor and it whined, so I took the
opportunity to try to silence it. That didn't work out.
See the transformer second from the left second row from the back.
http://img135.imageshack.us/img135/3100/transformercoilsinductooq8.jpg
That's what it had. So, I couldn't get liquid epoxy into it if I
tried.
I tried unsoldering it but it wasn't coming out unless I snapped the
board.
So I resigned my hope to merely being able to silence bagel shaped
transformers. Ones that I can get to.
I remember my old morex power supply card had them.
It'd be nice if I had some unviersal way to silence those. e.g. liquid
epoxy. I need some cheap way of trying it.
As mentioned, the ACDC adaptor thing didn't work out. It whined but
was in a housing.
I'm sure in the case of the morex power supply card , it was the
transformer that was whining. I managed to bare the nightmare of
putting my ear near it to find the culprit. The morex technicians
thought it was the transformers too, and admitted they whine!