The per-port regulators would be non-isolated. Probably feeding off
an internal 48V bus.
Yes, so that will be 90 to 95% efficient, but it is fed from an isolated supply
that at best will be 90%, probably less. Those numbers must be multiplied,
giving 81 to 86% overall efficiency--and I am
On Mon, 2 Feb 2009, Steve Underwood wrote:
Bernd Felsche wrote:
Ian Cowley i...@moffat.co.uk wrote:
Beware PoE switches that can't handle Class 3 (15W) on all ports.
Most have fans because 24 (or 48) x 15W is hot!
That's the power supplied .. which'd be at the far end of the wire.
The
A modern switched mode PSU ought to be more than 90% efficient,
In theory, yes, in practice, not likely. It is harder to get high efficiency
from an isolated supply than a non-isolated one. I get ads from IC
manufacturers all the time about there 90 to 95% efficient solutions, but these
are
[snipped]
You can do that by using fans other than the tiny, whiney, 40mm fans
that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin
fans at the back or front, pushing air in (hence the deep
dimensions), but the top and bottom would need recesses to allow
sufficient airflow when the
Singer XJ Wang wrote:
[snipped]
You can do that by using fans other than the tiny, whiney, 40mm fans
that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin
fans at the back or front, pushing air in (hence the deep
dimensions), but the top and bottom would need recesses to allow
A number of 1U products use large impeller fans
I've got a CPU in a 1U package with an impeller fan. It sounds like a jet
taking off! Its not quiet.
Wilton
___
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asterisk-users
We got a few of those in 1U chassis.. if you think those are quiet...
Steve Underwood wrote:
Singer XJ Wang wrote:
[snipped]
You can do that by using fans other than the tiny, whiney, 40mm fans
that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin
fans at the back or front,
Paul Hales pdha...@optusnet.com.au writes:
My memory of a HP procurve (a 2626 PWR from memory) was that it was
quite noisy - have they changed?
The 2626 is either extremely noisy or fairly noisy, depending on which
you happen to get. Luck of the draw; I haven't found a way to predict
it. The
How are you getting these 80 or 120mm fans in a 1U chassis? Remember you
got barely 45mm to play
with at the back and front of the switch. How are you going to mount a
80mm or 120mm fan on there? Are you assuming that the units mounted
above (or below) your switch is a short 1U? You can't
2009/2/2 Singer XJ Wang w...@pythian.com
[snipped]
You can do that by using fans other than the tiny, whiney, 40mm fans
that vibrate at 6000 to 18,000 Hz. A couple of 80 or 120 mm muffin
fans at the back or front, pushing air in (hence the deep
dimensions), but the top and bottom would need
Gordon Henderson wrote:
On Mon, 2 Feb 2009, Steve Underwood wrote:
Bernd Felsche wrote:
Ian Cowley i...@moffat.co.uk wrote:
Beware PoE switches that can't handle Class 3 (15W) on all ports.
Most have fans because 24 (or 48) x 15W is hot!
That's the power
Honestly, how are you guys expecting a 24 Port POE to be fanless?
Lets start with some logical points here:
1) 24 Ports x 15.4W/Port = 369.4Watts + Switch Power = ~400Watts... now
Power Supply isn't that efficient so you're getting probably a 500Watt
Power Supply (assuming 80%)...
2) with a
Okay, point out one reasonably priced PoE switch that has it.
Christian Victor wrote:
2009/2/2 Singer XJ Wang w...@pythian.com mailto:w...@pythian.com
[snipped]
You can do that by using fans other than the tiny, whiney,
40mm fans
that vibrate at 6000 to 18,000
Steve Underwood ste...@coppice.org wrote:
Gordon Henderson wrote:
On Mon, 2 Feb 2009, Steve Underwood wrote:
Bernd Felsche wrote:
Ian Cowley i...@moffat.co.uk wrote:
Beware PoE switches that can't handle Class 3 (15W) on all ports.
Most have fans because 24 (or 48) x 15W is hot!
That's the
Wilton Helm wh...@compuserve.com wrote:
A modern switched mode PSU ought to be more than 90% efficient,
In theory, yes, in practice, not likely. It is harder to get high
efficiency from an isolated supply than a non-isolated one. I get ads
from IC manufacturers all the time about there 90 to
Singer XJ Wang w...@pythian.com wrote:
Honestly, how are you guys expecting a 24 Port POE to be fanless?
Lets start with some logical points here:
1) 24 Ports x 15.4W/Port = 369.4Watts + Switch Power = ~400Watts... now
Power Supply isn't that efficient so you're getting probably a 500Watt
Lets start with some logical points here:
1) 24 Ports x 15.4W/Port = 369.4Watts + Switch Power = ~400Watts... now
Power Supply isn't that efficient so you're getting probably a 500Watt
Power Supply (assuming 80%)...
It'd still be a 400W PSU if it supplies 400W.
2) with a 1U chassis, you
This whole thread is getting stupid and I'd hope the people involved would
desist from this O/T drivel.
If you want a switch go to the shop, hand over some money and buy one... Like
every one else does and they're perfectly happy with their purchase.
The O.P. is not going to change the
Check out the HP ProCurve Switch 2610-24-PWR
-Original Message-
From: asterisk-users-boun...@lists.digium.com
[mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Chris Bagnall
Sent: February 1, 2009 6:58 AM
To: Asterisk Users List
Subject: Re: [asterisk-users] Quiet 24 port POE
I can find FANLESS 24 port PoE 10/100
That's an achievement in itself. Can you post details - I have quite a few
locations where that might be useful...
TIA.
Regards,
Chris
___
-- Bandwidth and Colocation Provided by http://www.api-digital.com
, 2009 11:58 AM
To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
Subject: Re: [asterisk-users] Quiet 24 port POE gig switch
I can find FANLESS 24 port PoE 10/100
That's an achievement in itself. Can you post details - I have quite a few
locations where that might be useful...
TIA
2009/1/31 OCG Technical Support supp...@ocg.ca
A little off topic but
I need to put a 24 port Gig PoE switch into a small office – no computer
room / rack etc. All CAT5 terminates near the owners desk (smart huh?).
I want to put a PoE switch in place, with 24 ports and Gig speed.
Luck
-Original Message-
From: asterisk-users-boun...@lists.digium.com
[mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Olivier
Sent: Monday, February 02, 2009 1:06 AM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Quiet 24 port POE
I guess one would have to ask whether 1000 Gb is necessary. That's a lot of
bandwidth. It might make sense to use it for central distribution. There are
also some that have one or two 1000 Gb ports that might be appropriate for
trunking and the rest 100 Mb which is probably fast enough for
Ian Cowley i...@moffat.co.uk wrote:
Beware PoE switches that can't handle Class 3 (15W) on all ports.
Most have fans because 24 (or 48) x 15W is hot!
That's the power supplied .. which'd be at the far end of the wire.
The efficiency of the PSU plays a big part in the heat dissipation.
The push
...@lists.digium.com] On Behalf Of Chris Bagnall
Sent: February 1, 2009 6:58 AM
To: Asterisk Users List
Subject: Re: [asterisk-users] Quiet 24 port POE gig switch
I can find FANLESS 24 port PoE 10/100
That's an achievement in itself. Can you post details - I have quite a few
locations
Bernd Felsche wrote:
Ian Cowley i...@moffat.co.uk wrote:
Beware PoE switches that can't handle Class 3 (15W) on all ports.
Most have fans because 24 (or 48) x 15W is hot!
That's the power supplied .. which'd be at the far end of the wire.
The efficiency of the PSU plays a big
My google search says fanless...
-Original Message-
From: asterisk-users-boun...@lists.digium.com
[mailto:asterisk-users-boun...@lists.digium.com] On Behalf Of Paul Hales
Sent: February 1, 2009 6:49 PM
To: Asterisk Users List
Subject: Re: [asterisk-users] Quiet 24 port POE gig switch
2009/2/2 Steve Underwood ste...@coppice.org
Bernd Felsche wrote:
Ian Cowley i...@moffat.co.uk wrote:
Beware PoE switches that can't handle Class 3 (15W) on all ports.
Most have fans because 24 (or 48) x 15W is hot!
That's the power supplied .. which'd be at the far end of the
A little off topic but
I need to put a 24 port Gig PoE switch into a small office - no computer
room / rack etc. All CAT5 terminates near the owners desk (smart huh?).
I want to put a PoE switch in place, with 24 ports and Gig speed. Everyone
I've researched so far is LOUD...
Hello,
I need to put a 24 port Gig PoE switch into a small office – no computer
room / rack etc. All CAT5 terminates near the owners desk (smart huh?).
I had a similar problem some days ago. 24-port GBit Switch in the middle
of a classroom...
I ended up with a kind of semi-loud setup: I
You will have a hard time finding a 24 port POE without fans - too
high of a power density. Do you really need 24 ports? perhaps a 12x12
otherwise multiple 8 or 12 port models may work
Do let us know if you find a 24 port without fans.
On Jan 31, 2009, at 2:06 PM, Claus Herwig wrote:
OCG Technical Support wrote:
A little off topic but
I need to put a 24 port Gig PoE switch into a small office – no computer
room / rack etc. All CAT5 terminates near the owners desk (smart huh?).
I want to put a PoE switch in place, with 24 ports and Gig speed.
Everyone
Of Darrick
Hartman
Sent: January 31, 2009 10:02 PM
To: Asterisk Users List
Subject: Re: [asterisk-users] Quiet 24 port POE gig switch
Importance: High
OCG Technical Support wrote:
A little off topic but
I need to put a 24 port Gig PoE switch into a small office - no computer
room / rack
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