Make:

I think the most clever solar actuator that I've ever seen was In essence two pistons. Inside each piston was freon. Basically the two pistons were shielded in such a way that when one was exposed to the sun, it would heat up, expanding the freon and force the panel to face the sun. In doing so, it shielded the other from the sun keeping it collapsed. When the sun swung around, or rose the next morning, the collapsed piston would heat up, and swing the panel the other direction, therby shielding the other... Nice passive system. No electrics and only two simple pistons.(Could also use bladders..).

jegan

Reply to this comment

Posted by: screaminscott on January 13, 2009 at 3:20 PM

I seem to remember a very simple solar tracker that used a photo resistor and a popsicle stick.

The photoresistor was wired in-line with the motor, so that the motor would turn when the sun shone on the resistor. The popsicle stick was mounted to the mechanism so it's shadow would fall on the photo-resistor when the solar array was pointed at the sun.

Then the photoresistor was in shade, the motor would not turn. When the sun shone on it, the motor would turn until the photo resistor was in shade again.

I don't recal how it reset for the start of the day though

Reply to this comment

Why the overkill of the bicycle rims? Having the axle pivot point so far away from the panels, mean gravity and wind stresses are working against the mechanism more than it needs to. A simple steel rod and bronze bushing pivot at the top & bottom centers would be simpler, cheaper and need very little in the actuator's power and throw. I like the concept of the solar expansion - contraction tracking. Another keep it simple way of thinking.

Reply to this comment