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From: dbell@cup.portal.com (David J Bell)
Newsgroups: sci.electronics
Subject: Re: sun tracker
Message-ID: <35459@cup.portal.com>
Date: 1 Nov 90 03:24:05 GMT
References: <13922@mcdphx.phx.mcd.mot.com>
Distribution: usa
Organization: The Portal System (TM)
Lines: 41

>Does anyone out there know of a SIMPLE system that would make
>a solar oven track the sun? I have to deal with two axis, the


OK, here's a crude ASCII sketch, showing how to do it with *one*
tracking axis. Pardon the liberties taken with angles of reflectance!
 
 
 
                    *  (Sun)
                .
             .
          .
     / .
   /.     Heliostat mirror. Rotates on an axis parallel to Earth's axis,
 /   .       angled so as to direct the Sun's light directly down the
      .         axis of rotation towards the fixed mirror. The angle of
       .           the mirror with the axis needs to be tweaked seasonally.
        .
         .
          . | Larger, fixed mirror.
           .|   Faces North, tilted North, (in N hemisphere, of course),
           .|     a bit off vertical. Since incident light *rotates* but
           .        stays on-axis, this mirror doesn't have to move,
        __ . __       nor does the oven.
        |     | \
        |     |  \
        |_____|   \
       Fixed oven. \  
                    \  Drive axis.
                     \
 
 
The fixed mirror could be eliminated, especially for installations at
fairly high latitudes, as long as the entrance to the oven needn't be
directly vertical.
 
The fixed mirror could be tilted *back*, towards the South, if it was
required to have the oven entrance horizontal...
 
Dave