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From: eric@chronon.UUCP (Eric Black)
Newsgroups: net.consumers,net.sci,net.audio,net.video,net.analog
Subject: Re: Line Voltage
Message-ID: <289@chronon.chronon.UUCP>
Date: Mon, 9-Jun-86 16:44:18 EDT
Article-I.D.: chronon.289
Posted: Mon Jun  9 16:44:18 1986
Date-Received: Wed, 11-Jun-86 00:38:19 EDT
References: <446@hropus.UUCP> <5436@alice.uUCp> <1039@kitty.UUCP>
Reply-To: eric@chronon.UUCP (Eric Black)
Organization: Chronon Computer Corp., Mtn. View, CA
Lines: 42
Xref: linus net.consumers:4968 net.sci:714 net.audio:8056 net.video:2614 net.analog:863
Summary: A rose by any other name gets through Purchasing

In article <194@sdics.UUCP> west@sdics.UUCP (Larry West) writes:
>In article <278@chronon.chronon.UUCP> eric@chronon.UUCP (Eric Black) writes:
>>  [ . . . ]
>>  We ended up installing a moby
>>  isolation transformer to get rid of common-mode spikes, and an UPS just
>>  as a line filter.  We still had occasional unexplained crashes...
>
>I don't understand.   The Uninterruptable Power Supply we
>had at the last place I worked (it's still there) effectively
>and completely isolated our power sinks from the SDG$E line
>power.   Never had a problem with power after that -- after
>all, we were drawing our power from about 15 car batteries,
>which were constantly being recharged from SDG$E power.   I
> [...]
>So my question is, how can you claim that it must be
>PG&E power [which I'm sure is as dirty as you say] when
>you have isolated yourself from it with a UPS and you
>still have the crashes?
>

Would have been nice...

It was a case of bureaucratic management refusing to approve the
purchase of an UPS ("we don't need to keep running if the power goes
down, you're an R&D shop, not a production environment").  An
obvious case of poor economy, since they spent as much or more on
lost time & productivity, not to mention actually fried hardware.
We did get them to approve a "power line filter".  What that turned
out to be was two-thirds of an UPS, i.e. the AC->DC converter, and
the DC->AC inverter.  That's not an UPS, as far as they were concerned.
I added one car battery, basically to act as a capacitor or extremely
small temporary energy storage, but they didn't know that.

I would expect that a real UPS would do the job.  Sometimes it's a case
of changing the name to protect the innocent...  Of course, the batteries
can add up to quite a bit of $$ if you want to be able to do more
than a quick sync and spin down the disks, if you've got nothing but
big washing machines for disks (those mini-Winchesters are sure nice!).

-- 
Eric Black   "Garbage In, Gospel Out"
UUCP:        {sun,pyramid,hplabs,amdcad}!chronon!eric