Day Brown wrote in a message to Jim Dunmyer:
 DB> There was a German study published partly in Computer Shopper, 
 DB> Jim.  I could look it up, but hopefully this will be clear 
 DB> enough...   
 DB> They started to look at fires in buildings which had large
 DB> numbers of computer systems in simultaneous operation. They 
 DB> noticed some increase in electrical fires in main switch boxes 
 DB> and associated transformers. 
 DB>
 DB> What they found was that there was a harmonic reaction, where 
 DB> two or more PFC power supplies would get in sync, trying to 
 DB> modify what each perceived as distortion in the incoming AC sin 
 DB> wave as it was delivered to the computer load.
 DB>
 DB> Within milliseconds every PFC in the building would pick up on 
 DB> a ripple reflected back into the local grid, and the whole 
 DB> setup then avalanches into a feedback loop forcing the 
 DB> current/voltage peaks to blow the mains in the building. 

What I don't understand is why there aren't power supplies that'll work with 
a 12vdc input.  I have heard of such,  but they don't appear to be out there 
at a reasonable cost,  compared to the "standard" stuff...
email: roy.j.tellason%tanstaaf@frackit.com 
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