Article View: sci.electronics
Article #17887UPS's that aren't
From: mason
Date: Sat, 08 Aug 1987 00:49
Date: Sat, 08 Aug 1987 00:49
33 lines
2337 bytes
2337 bytes
Sorry if this gets discussed every week here, but I don't usually read the
newsgroup. I will read it for a while in case this is an interesting topic
for you EEs, and you want to post replies. If it's a boring topic, please
reply by mail. I'll summarize if asked.
I was going away on 3 weeks vacation & wanted tmsoft to stay running & receiving
news & mail. So, I thought, I'll just go out & buy an Uninterruptible Power
System. So I did: a Sendon UPS-400W (400 watts, 5 millisecond max switchover).
Problem: the wave-form that comes out is positively ugly, and while switching
power supplies don't seem to care, tmsoft has a linear supply. It will run on
the battery and when the power comes back, it seems to switch OK; but when the
power goes away power drops long enough to be a problem (i.e. system crash 1/2
way through vacation)
I've seen switchers work (although they were probably pulling less current)
fine with it.
The wave form looks like a bad cross between a sin wave & a square wave,
switching between the two about the top of the crest & bottom of the trough.
There are also some ugly transients when it's switching between mains power and
the battery. I added a Radio Shack "Voltage Spike Protector with Broadband
Noise Filter" to the output with no discernable difference.
What I would like is something I can add on after the UPS that will clean
things up so the power supply works and I get rid of the nasty transients
(which mess up a terminal I use). (My electrical theory is pretty shaky, but
it seems to me a huge 60 Hz pass filter would do the trick). (I can also add
some more capacitance to my power supply, but I'm a little concerned about
inrush current).
Thanks
../Dave Mason, TM Software Associates (Compilers & System Consulting)
..!{utzoo seismo!mnetor utcsri utgpu lsuc}!tmsoft!mason
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!tmsoft!mason From: mason@tmsoft.UUCP Newsgroups: sci.electronics Subject: UPS's that aren't Message-ID: <161@tmsoft.UUCP> Date: Fri, 7-Aug-87 20:49:46 EDT Article-I.D.: tmsoft.161 Posted: Fri Aug 7 20:49:46 1987 Date-Received: Sun, 9-Aug-87 10:26:09 EDT Reply-To: mason@tmsoft.UUCP (Dave Mason) Followup-To: sci.electronics Organization: TM Software Associates, Toronto Lines: 33