Power Supply

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Why don't they make that AC ICE power connector on computer power
supplies any more? What was it for, a monitor? It was in addition to the
 AC input cord to take AC back out again.

Re: Power Supply


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My guess is that not enough people used it to justify the expense and/or
waste of space.

Re: Power Supply

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There are two relevant issues here, both in relation to turning
the monitor on and off.  

The old style AT power supplies cut the monitor's power at the same
time as the system.  This was easy to do as the power supplies were
controlled via a mains rated latching switch - both the computer
and the monitor were fed from this switch so both turned on and
off at the same time.  ATX power supplies don't have this, at least
not on the front panel, so switching a mains power supply would
mean a seperate relay or DIAC which would be physically big and/or
comparatively expensive.  The ATX power supplies that do have
monitor outlets don't switch it - they permanently feed the monitor
regardless of whether the computer is on or off.

In addition, slightly before ATX became widespread monitors began
shipping with DPMS power signalling as standard.  This means that
the monitor powers down when no signal is being fed to it.  This
isn't as good as cutting the power as the monitor is still drawing
some power in a standby mode, but it is most of the way there.

In short, controlling the monitor's power is both less important
and less practical than it used to be.  Since that was the main
merit of a monitor outlet the outlet is of less significance today.
Since it costs money to fit manufacturers frequently don't bother.

One final, and fairly unconnected point.  The power rating of PSUs
has increased steadily over the years.  Whereas 10-15 years ago a
250W PSU was pretty much standard, today the standard is probably
550W.  That makes everything inside the PSU case bigger and hotter.
Since the PSU is of standard dimensions it means that there isn't
as much spare space inside as there used to be.  If there are space
and cooling constraints then space consuming options such as the
monitor outlet are going to be obvious targets.

--
Andrew Smallshaw
andrews@sdf.lonestar.org

Re: Power Supply

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It happens everywhere, not just in the US.  Just don't confuse
pricing on surplus components with regular pricing.  I have an ITX
system in my bedroom that was from bargain components - the case
was 9 against the same supplier's current catalogue price of 60
- the PSU alone sells for 22.  The motherboard isn't a standard
stock item but it set me back 25 vs 139 for its nearest equivlent
in the book - again from the same supplier.  Someone made a loss
along the line there.

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A triac typically has an on resistance of a few hundred milliohms,
and even monolithic SSRs usually end with a triac as the current-bearing
component.  That means a power dissipation in the order of a watt
or so tops, maybe twice that in the US with the lower AC voltage.
Given that it is in the PSU, and therefore the last thing in the
system as far as airflow goes, on reflection I'll agree with you.
It is far less heat than the choppers put out.  Of course this is
all theoretical anyway since nobody actually does it.

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I hadn't thought of that but you're probably right - that is going
to be a problem when the outlet isn't switched.  Never misunderestimate
the stupidity of the end user.

Make the pie higher! Make the pie higher!

--
Andrew Smallshaw
andrews@sdf.lonestar.org

Re: Power Supply



On 2007-12-17, I wrote:

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I think I probably meant _triac_ there, and I still haven't learned
how to spell 'separate'.  Oh well, it _is_ the Christmas party
season.  At least that's my excuse and I'm sticking to it.

--
Andrew Smallshaw
andrews@sdf.lonestar.org

Re: Power Supply



On Mon, 17 Dec 2007 22:24:26 +0100 (CET), Andrew Smallshaw

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Generally for cost reasons an old fashioned mechanical relay
would be used.  If there were extremes of temp or very high
rate of cycling (or the designer just wanted long term
reliability) a solid-state relay would be used.

To simply switch a monitor, it would not have to be large or
very expensive, BUT they're not looking to add $1 to the
cost of each unit unless they feel it'd sell more and as you
mentioned in your prior reply, there is less demand today
with monitors able to be turned off by remote command from
the system.

Re: Power Supply



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I agree an electromagnetic relay is the obvious option if space
permits - it isn't just the overall size of the relay but its shape
too that could be a problem - a slim component could be easier to
fit in even if it is larger overall.  I wouldn't have thought an
SSR would be an option as whenever I've looked I've found them the
be disportionately expensive - 10+ seems to be the rule, at least
from the big distributors.  

Out of interest I checked the prices of suitable triacs and relays
from Farnell - admitted, this isn't an entirely valid comparision
any as any OEM will get keener prices direct from the manufacturer
but should provide at least an illustration. I found suitable triacs
for 52p in quantity 1000+ whereas the relay I found was 95p for
the same quantity.  However, a relay would stay cooler than a triac,
even if it isn't being switched much, so it isn't entirely clear cut.

Your point about saving money is the key one though.  If your bog
standard commodity PSU costs around $30 then it probably only costs
a quarter to a third of that to make.  The rest is fixed costs,
duties, margin etc.  Adding $1 to the cost of something that only
costs $8 to make is quite a big price hike and could make the
difference between being competitive and not.

--
Andrew Smallshaw
andrews@sdf.lonestar.org

Re: Power Supply



On Tue, 18 Dec 2007 18:42:40 +0100 (CET), Andrew Smallshaw

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Perhaps, but consider that some of these same distributors
may want pretty near the same cost for a fan, at least in
the states I've found Digikey/etc want way too much for some
parts I used to buy in volume for under $1 a piece.



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a solid state relay, or one built discretely, shouldn't
generate an excessive amount of heat just to power a
monitor, and tends to be far longer lived than a mechanical
relay, except that we're not talking about something meant
to be on a space probe or have a very large number of
cycles, it will most likely outlive the rest of the PSU
either way.



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It may raise support and warranty costs as well... IMO,
years ago only more technically inclined people owned
computers while these days everyone has one... and some may
not know you can't do something like daisey-chain one system
running through the outlet of another's supply and so on,
till you have several amps going through that relay or
whatever.  Plus, today's systems use more power so it's just
better all around not to use the same AC cord.

Re: Power Supply




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    ...just a sidenote (not that it appears you really need it:looked like a
typo to me) my 7th grade English teacher told me to watch out for that word.
Where you said, "...and I still haven't learned
how to spell 'separate'.", I was reminded she told me that it had *a rat* in
it.  Thx for causing me to recall such long-gone youth!  sdlomi2



Re: Power Supply

On Dec 17, 1:45 am, Broderick Crawford ililililil
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Bloody hell!! YOUR showing your age.......Broderick Crawford!!!! But
he WAS good, eh? hahahahahahahah

Re: Power Supply

Yes it's a throwback to long, long ago when IBM PC's and their clones first
came out.

Way back then all you have were simple text monochrome monitors (long before
vga ) and perhaps some of the early CGA monitors that had a short power cord
that just plugged into the AC recepticle on the back of the power supply
rather than a long ac cord that would plug into the wall.

That way, when you turned on the PC, it also powered up the monitor.


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looking for thin-wire connectors

Hello,

I am looking for a two-wire 'thin-wire' connector for my motherboard.
Specifically the two-wire one.

Does anyone know what the official name for these connectors are and
where they can be found?

thanks,
Todd

NOTE: Photo of what I am talking about is here:

http://www.pcguide.com/byop/diagrams/figure73.jpg

Re: looking for thin-wire connectors

On Mon, 14 Jan 2008 15:40:28 -0800, Todd Last

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If you only need one I suggest stopping by the local mom &
pop computer shop as any random system from the AT era
onward is likely to have these, the shop would be throwing
them away and could just pull one out before a retired
system was tossed.

I'm sure you could get one from an electronics house like
Digikey or Mouser but to order one piece plus shipping is
pretty costly for what it is, a little piece of plastic
worth a few pennies, plus they don't have any really unique
name they're just single row crimped insert 0.1" (2.54mm)
centered pin sockets... meaning you end up wading through a
lot of parts to find them at an electronics house.

Re: looking for thin-wire connectors

 :  Hello,
 :
 :  I am looking for a two-wire 'thin-wire' connector for my motherboard.
 :  Specifically the two-wire one.
 :
 :  Does anyone know what the official name for these connectors are and

IDC connectors.  Note that no one actually contemplates attaching a
real IDC connector with ribbon cable to those pins, but that's the
standard those header are built around.

 :  where they can be found?

Kony pointed you in the right direction.  Good luck

Re: looking for thin-wire connectors

On Tue, 15 Jan 2008 01:47:49 GMT, hgoldste@mpcs.com (Howard
Goldstein) wrote:

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While some OEMs have, and possibly still do use Insulation
Displacement Connectors, what most people are looking for
today are the type that have slide-in locking, crimp type
inserts.  While IDC type might be used in their place they
aren't always substitutes due to the fiddly nature of
getting separate loose wires to stay put while putting the
back cover on that connector type.

Re: looking for thin-wire connectors

 :  On Tue, 15 Jan 2008 01:47:49 GMT, hgoldste@mpcs.com (Howard
 :  Goldstein) wrote:
 :
 : > :  Hello,
 : > :
 : > :  I am looking for a two-wire 'thin-wire' connector for my motherboard.
 : > :  Specifically the two-wire one.
 : > :
 : > :  Does anyone know what the official name for these connectors are and
 : >
 : >IDC connectors.  Note that no one actually contemplates attaching a
 : >real IDC connector with ribbon cable to those pins, but that's the
 : >standard those header are built around.
 :
 :
 :  While some OEMs have, and possibly still do use Insulation
 :  Displacement Connectors, what most people are looking for
 :  today are the type that have slide-in locking, crimp type
 :  inserts.  While IDC type might be used in their place they
 :  aren't always substitutes due to the fiddly nature of
 :  getting separate loose wires to stay put while putting the
 :  back cover on that connector type.

I've never seen anyone try to do that, attaching loose wires onto an
IDC connector.  I can't think of too many more tedious things to try
to do (or many ways that'll get you to a nervous breakdown faster)
Hell I'm getting anxious just imagining trying to do it. Fortunately
it's very easy to clamp IDC connectors onto ribbon cable as the great
engineering god intended them to be fitted.  A bench vise works
perfectly.  Vise Grip pliers aren't quite as good but with practice
they'll do the trick.

Instead of trying to stick those loose wires in an IDC one'd be better
off connecting up the loose leads to a short length of separated
ribbon cable at the other end of the IDC, living with the ugliness but
retaining some sanity


Re: looking for thin-wire connectors

On Tue, 15 Jan 2008 03:40:50 GMT, hgoldste@mpcs.com (Howard
Goldstein) wrote:


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Well I didn't think it fit to make a home video, but yes
I've done it a few times.  It's do-able, but not fun.

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I found it easier to take a piece of transparent packing
tape and lay out the wires on it first, putting in dummy
placeholder pieces of wire when needed.

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Yes, I've done that a few times, though mostly with 40
conductor PATA cables, the 80 conductor are a bit smaller
than I feel comfortable dealing with when data is involved.

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Maybe, but once you set your mind on some ideal, it's a
challenge to get it done and the idea of it being
esthetically better is a reinforcement.

I still prefer the crimp-on inserts, but having bought some
from digikey in the past I vaguely recall it is highway
robbery what they charge for a small bent piece of metal,
the inserts alone.  Fortunately for the typical 2 or 3 pin
connectors I have plenty of spare systems or salvaged parts
that I never need to make the common ones but every now and
then doing something (not necessarily computer related) I
end up having to figure out which is the least painful
method of getting the job done.


Re: looking for thin-wire connectors

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Check Fry's at
http://shop3.outpost.com/product/1899476?site=sr:SEARCH:MAIN_RSLT_PG

the listing url may be better......
http://shop3.outpost.com/search?query_string=&cat=-46014&pType=pDisplay&resultpage=3&from=75&to=99


could be the item; I couldn't enlarge the pic.  If you have an old pice of
equipment, where you don't need/use the pc's speaker, may be able to
disconnect & easily extgract the wire & use its connector.

Re: Power Supply




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    ...cannot answer your question, but I do agree that it was neat to have
it available.  I always used it for monitors.  It made for one less device
to rely on power-bar, which allowed for a 1-button click to switch
everything off, for those who cycled their system daily (nightly?).
    Of course, sandy58, who offers SO much help to those seeking "advice" on
these ng's, does not remember such ps's--only reads about them in historical
articles.;)  Oh, but to have such youthfulness again!  (One day, I may learn
which pronoun to associate w/sandy58--(s)he???.  Doesn't matter, other than
I have to be careful NOT to slant my rantings.  Merry Christmas, whomever
you are.)  sdlomi2



Re: Power Supply



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Same to you, sdlomi2. and a very happy Hogmanay to you and yours.
Slainte'.

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