Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!n8emr!uncle!donlash
From: donlash@uncle.UUCP (Donald Lashomb)
Newsgroups: comp.sys.att
Subject: Re: ups for 3b1
Keywords: ups 3b1 squarewave
Message-ID: <776@uncle.UUCP>
Date: 23 Mar 90 21:55:27 GMT
References: <3005@umbc3.UMBC.EDU>
Reply-To: donlash@uncle.UUCP (Donald Lashomb)
Organization: U.N.C.L.E.
Lines: 28

In article <3005@umbc3.UMBC.EDU> motteler@umbc3.UMBC.EDU (Howard E. Motteler) writes:
>
>Does anyone know how the 3b1 power supply holds up when fed the square
>wave output typical of most UPS's?  I know this causes a problem for
>some switching power supplies.

I'm using a UPS with my 7300.  It's a SAFE brand model 425 (425w I assume).
The output is described as a "modified square wave".  I've looked at the
output with an o'scope - it would really scare you, all kinds of jagged peaks
and valleys.  BUT the 7300 doesn't seem to mind.  I should also mention that,
not trusting that trashy looking waveform, I've got a TrippLite IsoBar
noise filter/surge suppressor between the UPS and the 7300.  (8-outlet
IsoBar with the 7300 plugged into the last, most filterred, outlet.)  In fact
I've got 2 IsoBars, one before and one after the UPS:

     117vac ---> IsoBar ---> UPS ---> IsoBar ---> UnixPC

This system has weathered approx 5-10 brownouts per day for 2 years with no
troubles.  We have alot of low-voltage problems in my area.

The following is an unabashed product endorsement:

    TrippLite IsoBar model IB-8 noise filter/surge suppressors are great.
    I have a hi-freq welder on the same branch circuit as my UnixPC.  The
    IsoBar protects the computer with no problem.

May all your cycles be 117vac @ 16.666ms
-Don