Sun position sensor for two axis tracking

In a solar collector system, including a solar collector and a two axis tracking apparatus driving the solar collector in two respective axes in response to an unobscured sun to track the sun during its apparent movement from east to west, improved means for repositioning the solar collector after a period of sun obstruction, said improvement comprising:

• a fixed portion of a geodesic dome shaped support having several planar dome facets, said support positioned to face the noonday sun with one of said dome facets normal to the incident solar energy and additional facets sequentially normal to the incident solar energy during said apparent solar movement east to west during various seasons of the year;
• a plurality of solar sensors each mounted on the planar surface of a respective dome facet and providing an electrical output signal representing the amount of solar incidence on a respective sensor;
• means for electrically connecting said solar sensors in a matrix array of two matrix axes, said matrix axes corresponding to respective axes of said two axis tracking system, including matrix axes designating means for designating the respective matrix axes corresponding to the dome facet which is substantially normal to the sun;
• and
• driver means, including collector position designating means designating the solar collector two axis position, for driving the solar collector two axis position, and for driving the solar collector until the solar collector two axis position matches the respective matrix axes corresponding to the dome facet which is at that time substantially normal to the sun.

A sun position sensor for a solar collection system comprising:

• a fixed portion of a geodesic dome shaped support having several planar facets thereon adapted to sequentially face the sun at substantially normal angles of solar incidence during the apparent solar movement from east to west during various seasons of the year, said facets each corresponding to an associated solar azimuth and elevation angle;
• a solar sensor mounted on the planar surface of each of said facets providing an electrical signal representing the amount of solar energy incident on the respective facet;
• a first group of threshold trigger amplifiers each receiving the electrical signals from one or more solar sensors of substantially the same azimuth angle;
• a second group of threshold trigger amplifiers each receiving the electrical signals from one or more solar sensors of substantially the same elevation angle;
• said first and second group of threshold trigger amplifiers including means for presetting a threshold signal level which said electrical signals must exceed before the respective threshold trigger amplifier is triggered and provides an output, and wherein only one threshold trigger amplifier in each group is triggered, corresponding to the solar sensor and associated dome facet receiving the highest amount of solar energy;
• digital encoder means activated by said output of said respective triggered amplifiers to provide digital data corresponding to the azimuth and elevation of the sun;
• a solar collector having discrete azimuth and elevation angles at which the sun will be collected;
• tracking means including azimuth and elevation drive means for moving said solar collector and tracking the sun during unobscured solar conditions as it traverses an apparent east to west movement;
• means coupled to the solar collector for determining the solar collector position in terms of azimuth and elevation and providing digital data corresponding thereto;
• and
• comparator means receiving the respective digital data from said digital encoder means corresponding to the sensed azimuth and elevation of the sun, and the digital data corresponding to the solar collector position, and providing respective drive signals to the azimuth and elevation drive means to move said solar collector until the solar collector position is substantially equal to the sensed azimuth and elevation of the sun.