[rescue] WTB/Advice: UPSs

[Greg A. Woods]

[ On Friday, April 5, 2002 at 22:57:37 (-0500), Eric Webb wrote: ]
> Subject: Re: [rescue] WTB/Advice: UPSs
>
> But is there anything to prove that a machine isn't going to work all the 
> same with the square wave?  Maybe it's yucky to you, but how do we know it's 
> yucky to the machine?

I don't know a huge amount about switching power supply design, but I do
know the general theory of their operation (and have lots of references
about them and the prerequisite background science on my shelf to help
me with the details :-).  Square waves can be bad as input to such a
device because unless they've been taken into account in the design they
can cause ringing and harmonics as they are processed by the circuit.
Such ringing and harmonics could have all kinds of unwelcome secondary
effects.

If you have the circuit diagrams and/or design documents for your power
supply and you have, or can find someone with, enough understanding of
electronics to analyse the design then you can probably answer yours
question yourself.

Or if you can find the licensed engineer who designed, or signed off on
the design of, the power supply in your machine then you can ask him or
her whether it will find square-wave power to be "yucky" or not!  ;-)

Otherwise if you care about the reliability and lifetime of your machine
you should probably assume its power supply was designed only for sine
wave input and keep it at that.

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods at acm.org>;  <g.a.woods at ieee.org>;  <woods at robohack.ca>
Planix, Inc. <woods at planix.com>; VE3TCP; Secrets of the Weird <woods at weird.com>