Hello All...
I am finally in the process of finishing up an install on a personal repeater
system and I've come to a dead end, I'm hoping this group might have some
answers. My goal is to provide emergency power for all of the equipment in my
cabinet for as long as possible, without totally going overboard or over budget.
First off, here's the equipment that I have:
Vertex VXR-7000 UHF Desktop Repeater @ 50W
AC PWR: 1AMP @ 120VAC (TX) .5AMP @ 120VAC (STBY/RX)
DC PWR: 7.5AMP @ 12V (TX) 1AMP @ 12V (STBY/RX)
Alinco DM-330MV 35AMP Power Supply
AC PWR: 120VAC (Unknown AMP/Watt Draw)
Pentium II 233 Personal Desktop Computer (No Monitor)
AC PWR: 150W PS @ 120VAC
Connected to the Alinco Power Supply I have two UHF mobile radios and a
repeater controller, the total draw, even while in transmit, is less than 5
amps. At my disposal for this project right now is an Automatic Transfer Switch
from West Mountain Radio, Two 100A/Hr gel-cell batteries and a AC UPS that will
accept external batteries (through a slight modification).
So, what is the best method of powering all of this equipment?
My first thought would be to buy a completely separate UPS to power the
computer and then connect the two batteries to the Vertex Repeater and other DC
items through the Automatic Transfer Switch. However, this creates a few
concerns. First, Vertex is telling me that powering the repeater from DC is not
only inefficient, but if done incorrectly, could cause numerous problems
(including severely damaging the repeater). I was told in most cases, if the
power goes out and you drain the batteries, you do NOT want to reconnect the
A/C power to the repeater until the batteries have been fully recharged, the
on-board charging circuit cannot handle the load. A low-voltage cutoff switch
might work in this situation, but I've done some research and most are out of
my price range for this project. The other complicating factor here is the fact
that the Vertex repeater produces a slight charging voltage meant to maintain
the batteries, not recharge them, I doubt that the low voltage disconnect
circuit or the Automatic Transfer Switch would like voltage going the other
direction.
The other alternative is to power everything off the UPS I acquired, running
everything continuously on A/C. However, I'm also hearing that this process
would be inefficient going from DC to AC and in some cases, back to DC. I also
doubt that I would be able to get much life from a UPS (even with the two
100A/Hr batteries connected).
So, does anyone have any suggestions?
Justin W. Pauler
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
