[Milsurplus] Re 25hz

[W7QHO at aol.com]

In a message dated 11/25/07 6:30:44 AM, lafrance at att.net writes:


> Here's a very interesting article about rotary frequency changers, a few of 
> which were still in
> service as of the article's 2003 date:
> http://services3.ieee.org/organizations/pes/public/2003/sep/peshistory.html
> 
> 

Interesting article indeed.

At a government site in the UK where I worked in the 70's there was a 
building full of 50 to 60Hz rotary power converters which had been found necessary to 
run earlier US equipment installed there.   With the later capability of 
almost all electronics to work off of 50 - 60 Hz power the converters were taken 
out of service, at which time it was discovered that these units had been 
providing a very beneficial power smoothing function in addition to frequency 
changing,   Local 50 Hz mains power turned out to be rather dirty. i.e., prone to 
numerous transients, surges and short interruptions which the inertia of the 
heavy rotating components of the old system had been filtering out for the most 
part.

Dennis D. W7QHO
Glendale, CA



**************************************
Check out AOL's list of 2007's hottest 
products.

(http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/milsurplus/attachments/20071125/216e8cfe/attachment.htm