[time-nuts] Thunderbolt and UPS, Was any negatives ?

[GandalfG8 at aol.com]

In a message dated 01/06/2009 18:03:02 GMT Daylight Time,  
pete at petelancashire.com writes:

Anyone  running with a power supply with built in UPS ?

A long time ago  (>15yrs) I did project that for a supply did
a/c line -> battery  -> +5/+12/-12. A side advantage was  great
isolation.


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Probably the easiest way to do that for the Tbolt would be to generate pos  
and neg 12 volt supplies, either from a single or pair  of transformers, 
with the pos 5 volt derived from the pos 12, and also  use the supplies to 
trickle charge a couple of 12 volt sealed lead acid  batteries.
It would be easy enough to calculate ratings based on required battery  
running period and the battery on the neg 12 rail could be significantly  lower 
capacity than that on the positive supply.
 
regards
 
Nigel
GM8PZR