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From: larry@tapa.uucp (Larry Pajakowski)
Newsgroups: sci.electronics
Subject: Re: 1 phase to 3 phase conversion
Keywords: phase conversion
Message-ID: <1991Apr9.002557.3578@tapa.uucp>
Date: 9 Apr 91 00:25:57 GMT
References: <1991Mar28.191005.1653@rodan.acs.syr.edu> <3613@polari.UUCP> <4725@osc.COM>
Reply-To: larry@.UUCP (Larry Pajakowski)
Distribution: na
Organization: Pata System Consultants
Lines: 20

Some of the back issues of the magazie "Live Steam" about 2 years ago had an
article with a couple of easy ways to do this.  One comment is that all this
stuff is at line potential.

The first is with an idler 3 phase motor.  Your feed your single phase into 3
of the 3 connections and use 2 capacitors to the third.  One capacitor is a
motor starting (short duty) and the second is a motor run cap.  

Second is to use a capaictor as a phase shifter into the 3rd lead.  Again
another larger capacitor is needed to get things started.  I've only seen this
used on smaller motors like grinders.  Refrigeration supply houses are a good
source of motor run caps.

This isn't as far fetched as it sounds.  I know several people who run milling
machines and the like with these circuits.

Molyphase is a commercial brand of the idler motor type.  I've seen them
advertised in some of the machinery catalogs.

Larry