Building a Solar Parabolic

[ebarker]

About 50 years ago an engineer at TI invented a 4 quadrant sensor, used for guided missles.

Same concept



up/down difference = (sum A + B) - (sum C + D)

left/right difference = (sum A + C) - (sum B + D)

You need 4 light sensors

you could do the whole thing in analog electronics, op-amps and such,

OR

do it all in software using 4 A/D channels on a processor, like an old robot controller.

[MrForbes]

how sharp is the focus? If it's not too sensitive, you could use a non-feedback system. I'm assuming you have one axis of rotation. Just program what angle it needs to be at each time of day, have it move a bit when needed. The position will change over the year, so program that in as well.