Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!elroy.jpl.nasa.gov!peregrine!ccicpg!cci632!rit!ritcsh!sic
From: sic@ritcsh.cs.rit.edu (Eric A. Neulight)
Newsgroups: sci.electronics
Subject: Re: Power Factor
Keywords: Capacitive
Message-ID: <957@ritcsh.cs.rit.edu>
Date: 15 Jan 90 21:06:32 GMT
References: <12525@cbnewse.ATT.COM> <1347@wrgate.WR.TEK.COM>
Reply-To: sic@ritcsh.cs.rit.edu.UUCP (Eric A. Neulight)
Distribution: usa
Organization: Computer Science House @ RIT, Rochester, NY
Lines: 22

In article <12525@cbnewse.ATT.COM> sherwood@cbnewse.ATT.COM (charles.a.sherwood) writes:
>Someone stated that they did not know of any equipment that caused a capacitive
>power factor. One of the engineers in our power supply group told me that
>switch mode power supplies have a capacitive factor of about .65 due to the
>low conduction angle. This would imply that any electronic equipment that uses 
>a switch mode power supply would have a has a capacitive power factor. 

Running a synchronous motor 'overexcited' (with high field current) will create
a capacitive load, and it is adjustable.  This is common practice in industry
to balance the power factor.  The motor runs hotter, but if rated current is
not exceeded (they are made to handle it), not only do you get greater
maximum torque, but it can be put to usefull work.

I don't fancy trying to correct the power factor with a bank of switchers :-)

==============================================================================
CLAIMER:  Well -- I wrote it!                       Eric Alan Neulight
"Nothing is Impossible -- Just Impractical."      Electrical Engineering
"For every Lock, there is a Key."                 Computer Science House
"INSANITY is just a state of mine."         Rochester Institute of Technology
     BITNET: EAN4762@RITVAX                     IP: sic@ritcsh.cs.rit.edu
==============================================================================