| 摘要 |
A solar tracking device (10) has a shadow plate (12) mounted above support (14). A first pair of photoresponsive sensors (18) is mounted beneath the shadow plate (12). A second pair of photoresponsive sensors (20) is also mounted beneath the shadow plate (12), with a line passing through the second pair of photoresponsive sensors (20) being at an angle to a line passing through the first pair of photoresponsive sensors (18). A fifth photoresponsive sensor (21) is mounted above the shadow plate (12) in a cylindrical enclosure (23). Each of the sensors (18, 20, 21) has a microscopic opening (22) which admits light to the sensors. A "no-hunt" control circuit (100) receives inputs from each of the first and second pairs of sensors (18 and 22) to control operation of positioning motors (134 and 136). Coincidence of inputs from each sensor (18 or 20) and a clocking signal (192) are used to inhibit inputs from each sensor (18 or 20) to motors (134 and 136). The fifth sensor (21) is used to control operation of a pump (206) for a heat transfer fluid. A drive mechanism (300) for a parabolic solar energy receiver (202) has a nut (320) threaded on a drive screw (316). The nut (320) is mounted on orthogonal pivots (324, 385). A support (322) for the drive screw (316) and a drive motor (318) is also mounted on orthogonal pivots (326, 410).
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