arritt@kuhub.cc.ukans.edu (02/17/90)
I'm in the market for a 386sx, and our state contract says "thou
shalt buy Zenith and no other". The Zenith 386sx has a 120 watt
power supply, which seems unreasonably small. The Zenith sales
rep said they use some special chips which reduce the power
requirements. This whole business seems weird -- the power supply
is a pretty small-dollar item in the context of the price of the
system, and the power usage of pc's is an insignificant contributor
to the electric bill of any governmental institution (i.e. Zenith's
primary market). Just what are they trying to accomplish by using
such a low-rating power supply?
Anyway, my questions to you fellow netters: Does anyone have
experience with these units (or other Zeniths with very small
power supplies)? Is this a practical consideration? What happens
if I add a tape backup, a transputer board, maybe a few more
megabytes of memory, or other electrical load?
Whatever advice, anecdotes, warnings, etc. you can offer would be
appreciated.
________________________________________________________________________
Ray Arritt |
Dept. of Physics and Astronomy |
Univ. of Kansas |
Lawrence, KS 66045 |
arritt@kuhub.cc.ukans.edu |
arritt@ukanvax.bitnet |
easton@zds-oem.UUCP (Jeff Easton) (02/24/90)
In article <22275.25dc6dd8@kuhub.cc.ukans.edu>, arritt@kuhub.cc.ukans.edu writes: > I'm in the market for a 386sx, and our state contract says "thou > shalt buy Zenith and no other". The Zenith 386sx has a 120 watt > power supply, which seems unreasonably small. The Zenith sales > rep said they use some special chips which reduce the power Ack! special chips? I happen to have a Z386sx power supply here, the ratings are as follows: +5v 14A +12v 4A -12V .5A Now lets look at the load of a typical computer. First off, the main board, fully loaded with 8 megs of RAM, coprocessor, etc. proabably takes around 4 amps of the 5V line with around 100 ma on the +-12v lines. I'm guessing on the high side here. That leaves 10A @ 5V for the slots. One slot has a VGA card, less than an amp @ 5V. That leaves you with slightly more than 2 amps @ 5v per slot, plenty for most cards. The drives take small amounts of current @ 5v, maybe an amp for all three. The drives do require maybe 1.5 amps from the 12v line, more for startup. This just about fits the supply ratings above. > Anyway, my questions to you fellow netters: Does anyone have > experience with these units (or other Zeniths with very small > power supplies)? Is this a practical consideration? What happens > if I add a tape backup, a transputer board, maybe a few more > megabytes of memory, or other electrical load? Well, I have a little experience with Zenith units ;^). The transputer boards could draw quite a bit of current. Most other AT type boards will be okay. > Ray Arritt | Jeff Easton Zenith Data Systems Systems Engineer OEM Engineering easton@andrews.edu --or-- easton@zds-oem.zds.com I'd rather be Water Skiing...