OT Is magnetic extra magnetic shielding required inside computer?

[Andre Jute[_2_]]

Can I have an opinion please, gentlemen.

To reduce the number of noisy fans inside a big custom-built computer,
we need to put the power supply right next to the hard disk. In most
computers the two are at opposite corners, maximum separation. Don't
worry about heat management, that'll be taken care of. This question
is only about magnetic shielding.

Is it necessary to add magnetic additional shielding between the power
supply and the hard disk in the proposed layout? If yes, what material
and how much of it?

Thanks.

Andre Jute
Visit Andre's books
http://coolmainpress.com/andrejute.html

[Don Pearce[_3_]]

On Mon, 29 Aug 2011 13:06:55 -0700 (PDT), Andre Jute
> wrote:

>Can I have an opinion please, gentlemen.
>
>To reduce the number of noisy fans inside a big custom-built computer,
>we need to put the power supply right next to the hard disk. In most
>computers the two are at opposite corners, maximum separation. Don't
>worry about heat management, that'll be taken care of. This question
>is only about magnetic shielding.
>
>Is it necessary to add magnetic additional shielding between the power
>supply and the hard disk in the proposed layout? If yes, what material
>and how much of it?
>
>Thanks.
>
>Andre Jute
>Visit Andre's books
>http://coolmainpress.com/andrejute.html

No. Computer power supplies are switchers, and don't produce large
magnetic near fields the way a transformer supply would. You can put
the supply as close as you like to the hard drive without any worries.

d

[Andre Jute[_2_]]

On Aug 29, 9:29*pm, (Don Pearce) wrote:
> On Mon, 29 Aug 2011 13:06:55 -0700 (PDT), Andre Jute
>
>
>
>
>
> > wrote:
> >Can I have an opinion please, gentlemen.
>
> >To reduce the number of noisy fans inside a big custom-built computer,
> >we need to put the power supply right next to the hard disk. In most
> >computers the two are at opposite corners, maximum separation. Don't
> >worry about heat management, that'll be taken care of. This question
> >is only about magnetic shielding.
>
> >Is it necessary to add magnetic additional shielding between the power
> >supply and the hard disk in the proposed layout? If yes, what material
> >and how much of it?
>
> >Thanks.
>
> >Andre Jute
> >Visit Andre's books
> >http://coolmainpress.com/andrejute.html
>
> No. Computer power supplies are switchers, and don't produce large
> magnetic near fields the way a transformer supply would. You can put
> the supply as close as you like to the hard drive without any worries.
>
> d

Thanks, Don.
-- AJ

[Patrick Turner]

On Aug 30, 6:29*am, (Don Pearce) wrote:
> On Mon, 29 Aug 2011 13:06:55 -0700 (PDT), Andre Jute
>
>
>
>
>
> > wrote:
> >Can I have an opinion please, gentlemen.
>
> >To reduce the number of noisy fans inside a big custom-built computer,
> >we need to put the power supply right next to the hard disk. In most
> >computers the two are at opposite corners, maximum separation. Don't
> >worry about heat management, that'll be taken care of. This question
> >is only about magnetic shielding.
>
> >Is it necessary to add magnetic additional shielding between the power
> >supply and the hard disk in the proposed layout? If yes, what material
> >and how much of it?
>
> >Thanks.
>
> >Andre Jute
> >Visit Andre's books
> >http://coolmainpress.com/andrejute.html
>
> No. Computer power supplies are switchers, and don't produce large
> magnetic near fields the way a transformer supply would. You can put
> the supply as close as you like to the hard drive without any worries.
>
> d- Hide quoted text -
>
> - Show quoted text -

I'd guess you are right. But I had a guy tell me he made up water
cooled heatsinks for his complex PC system and then remote linear
power supplies. All a bit over the top and crazy but not to the guy
who was building the PC.

Most SMPS for PCs have a peforated steel mesh case which gives some
screening against RF and magnetic fields at HF. The mains in such SMPS
is rectified by diodes to charge a large electro, then a chopper
circuit switches the DC at RF to make a square wave which is applied
to small HF tranny and then diodes charge caps for 12V dc and 5Vdc,
and the whole lot has complex solid state regulation controls, but
there are no strong 50/60Hz stray magnetic fields generated. I've
looked inside lots of my PCs and never seen any attempt to screen with
mu-metal or anything else much.

Patrick Turner

[Arny Krueger[_4_]]

"Patrick Turner" > wrote in message
...
On Aug 30, 6:29 am, (Don Pearce) wrote:
> On Mon, 29 Aug 2011 13:06:55 -0700 (PDT), Andre Jute
>
>
>
>
>
> > wrote:
> >Can I have an opinion please, gentlemen.
>
> >To reduce the number of noisy fans inside a big custom-built computer,
> >we need to put the power supply right next to the hard disk. In most
> >computers the two are at opposite corners, maximum separation. Don't
> >worry about heat management, that'll be taken care of. This question
> >is only about magnetic shielding.
>
> >Is it necessary to add magnetic additional shielding between the power
> >supply and the hard disk in the proposed layout? If yes, what material
> >and how much of it?
>
> >Thanks.
>
> >Andre Jute
> >Visit Andre's books
> >http://coolmainpress.com/andrejute.html
>
> No. Computer power supplies are switchers, and don't produce large
> magnetic near fields the way a transformer supply would. You can put
> the supply as close as you like to the hard drive without any worries.
>
> d- Hide quoted text -
>
> - Show quoted text -

> I'd guess you are right.

He's righter than rain. For one thing almost every computer switching power
supply is put inside a tightly-closed ferrous metal box. Secondly, the the
disk drive's most EM-field sensitive components are also highly shielded.
Furthermore, the coercivity of modern magnetic media is very high, and the
signals that are involved around the record/play head are respectible.

I've built dozens of computers where the hard drives were stacked up right
next to the power supply, like the one I'm typing on right now. Its not a
bad idea because power supplies are typically places around which some of
the highest air flow exists.

> But I had a guy tell me he made up water cooled heatsinks for his complex
> PC system and then remote linear
> power supplies. All a bit over the top and crazy but not to the guywho was
> building the PC.

None of that had anything to do with EMI. Linear power supplies for a
computer? Then he is also crazy.

[Patrick Turner]

On Aug 30, 10:02*pm, "Arny Krueger" > wrote:
> "Patrick Turner" > wrote in message
>
> ...
> On Aug 30, 6:29 am, (Don Pearce) wrote:
>
>
>
>
>
> > On Mon, 29 Aug 2011 13:06:55 -0700 (PDT), Andre Jute
>
> > > wrote:
> > >Can I have an opinion please, gentlemen.
>
> > >To reduce the number of noisy fans inside a big custom-built computer,
> > >we need to put the power supply right next to the hard disk. In most
> > >computers the two are at opposite corners, maximum separation. Don't
> > >worry about heat management, that'll be taken care of. This question
> > >is only about magnetic shielding.
>
> > >Is it necessary to add magnetic additional shielding between the power
> > >supply and the hard disk in the proposed layout? If yes, what material
> > >and how much of it?
>
> > >Thanks.
>
> > >Andre Jute
> > >Visit Andre's books
> > >http://coolmainpress.com/andrejute.html
>
> > No. Computer power supplies are switchers, and don't produce large
> > magnetic near fields the way a transformer supply would. You can put
> > the supply as close as you like to the hard drive without any worries.
>
> > d- Hide quoted text -
>
> > - Show quoted text -
> > I'd guess you are right.
>
> He's righter than rain. For one thing almost every computer switching power
> supply is put inside a tightly-closed ferrous metal box. Secondly, the the
> disk drive's most EM-field sensitive components are also highly shielded.
> Furthermore, the coercivity of modern magnetic media is very high, and the
> signals that are involved around the record/play head are respectible.
>
> I've built dozens of computers where the hard drives were stacked up right
> next to the power supply, like the one I'm typing on right now. Its not a
> bad idea because power supplies are typically places around which some of
> the highest air flow exists.
>
> > But I had a guy tell me he made up water cooled heatsinks for his complex
> > PC system and then remote linear
> > power supplies. All a bit over the top and crazy but not to the guywho was
> > building the PC.
>
> None of that had anything to do with EMI. *Linear power supplies for a
> computer? Then he is also crazy.


I don't question the mental status quo of ppl who like their vast home
based computing arrangements to be +130dB more complex and cabable
than my own humble Dell set which I mainly use to send these cheap
telegrams which you so often find so painful to read.

I'm impressed that PCs work as well as they do without all the
troubles I get with people bringing me CD players, solid state amps,
and many other analog things all designed without adequate shielding,
protection etc. It should be impossible to zap any modern peice of
electronics, but an army of repair guys are still required.

Patrick Turner.