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Started by Cynthia Katzman
Fri, 08 Feb 1985 20:38
Help...RFP - for Broadband Co-axial Cable Plant expansion
Author: Cynthia Katzman
Date: Fri, 08 Feb 1985 20:38
Date: Fri, 08 Feb 1985 20:38
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We here at Harvard are considering expanding our present Broadband cable plant. We are in the process of putting together an RFP for the expansion project. It would be most useful if we could see what other sites have put as their technical specifications, and the request for proposal in general. Thanks in advance! Cynthia Katzman Harvard University harvard!h-sc4!katzman
Re: Help...RFP - for Broadband Co-axial Cable Plant expansion
Author: Ron Natalie <ron>
Date: Mon, 11 Feb 1985 02:57
Date: Mon, 11 Feb 1985 02:57
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> We here at Harvard are considering expanding our present Broadband > cable plant. We are in the process of putting together > an RFP for the expansion project. It would be most useful if we > could see what other sites have put as their technical specifications, > and the request for proposal in general. > > Thanks in advance! > If you can avoid cable, how about fiber optics? They are much nicer to work with data wise than buying Sytek kludge-boxes and trying to share a hunk of coax. -RON
Re: Stand-by power supply for a Broadband cable plant
Author: Phil Ngai
Date: Sun, 29 Sep 1985 04:51
Date: Sun, 29 Sep 1985 04:51
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I expect that most standby power supplies can switch fast enough to
keep your equipment alive. We are using one from Topaz which switches
in about 10 mS. As long as it is less than one cycle of 60 Hz power
you will probably be in good shape. I tested the Topaz on a florescent
lamp: it stayed alive.
If you do go with the much cheaper standby instead of a true UPS, make
sure you have a regular testing program for the standby. (e.g. unplug
it from the wall every month or so) Otherwise you could be driving
around with a flat spare.
--
God made atheists too.
Phil Ngai (408) 749-5720
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil
ARPA: amdcad!phil@decwrl.ARPA
Re: Stand-by power supply for a Broadband cable plant
Author: Henry Schaffer
Date: Sun, 29 Sep 1985 17:43
Date: Sun, 29 Sep 1985 17:43
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> I expect that most standby power supplies can switch fast enough to > keep your equipment alive. We are using one ... which switches > in about 10 mS. > -- > Phil Ngai (408) 749-5720 When switching the AC power to equipment, and trying to do it fast - sometimes problems relating to phase coherency of the power sources can arise. In high current equipment (which your's probably is not) you can have a very high current inrush if your standby current is switched in out of phase with the current which previously was there. (It has to do with the remanant magnetic field in the transformer. It can get particularly tricky when powering large AC motors.) This doesn't happen (of course) when switching between two DC sources. --henry schaffer
Re: Stand-by power supply for a Broadband cable plant
Author: Phil Ngai
Date: Tue, 01 Oct 1985 06:58
Date: Tue, 01 Oct 1985 06:58
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In article <505@ecsvax.UUCP> hes@ecsvax.UUCP (Henry Schaffer) writes:
> When switching the AC power to equipment, and trying to do it
>fast - sometimes problems relating to phase coherency of the power
>sources can arise.
Good point. I should add that our unit is a 400VA model.
--
Arthur Rudolph believed that technology is morally neutral and so,
therefore, are those who create it.
Phil Ngai +1 408 749-5720
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil
ARPA: amdcad!phil@decwrl.ARPA
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