[plug] re: ups

[Alan Howard]

On Thu, 09 Nov 2000, Leon Brooks wrote:
 <snip>
> 
 
> (4) you lose some extra percentage of your power, exactly how much being
> dependent on lots of things but for a TL494 design probably around 20%;
> 

with carefull design you can get these above 90% even though some designs I see
( as part of my job) in servicing and repairing consumer electronic products are
extremly poor

<snip>

> (5) you have to carry an extra piece of electronics around instead of a cable.
> 
> Having pulled apart a few laptops, the incoming power gets fed to a switchmode
> on its way to the battery anyway, and fed to another on the way out. Modern,
> well-designed switchers should be well in excess of 90% efficient, and I imagine
> that the people who design the PSUs for $4000 laptops are quite good at
> high-efficiency designs.
> 

you would think so , but i've seen some power supplies in $6 000 + projection
tv's and LCD projectors that have made me cringe. the power supply looked like
a after thought , very little effort was made and repairing was a nightmare.

alan howard