mirrors single or array

[ljd10]

what if a person built a parabolic mirror (or several) and made the focal point  like 15,20,30 feet. in the case of an array you could use a little trig to physically aline them  (say if you use 3)  to a mutual 15,20,30 ft point--the have the heliostat program try to keep the smaller concentrated group on target. anyway part of a summer experiment. wondering if anybody had anybody had any insight to that.

[Gabriel]

I know you could use the heliostat program to point a parabolic mirror at the sun without any trouble. The problem with using a parabolic mirror with a focal point which is very far away is that it could very easily start a fire if something went wrong (and something always will). I guess it might be possible, but there would be a lot of complications in getting it to work.   

[ljd10]

I agree on the negative possibilitys but with the way you have programed  sun tracker through the printer port and standard stepper drivers you can use "large" stepper motors and put all the mirrors on 1 bar. if the idea starting afire is to great--put reguler mirrors on 1 bar but phisicaly arrange them on 1 focal point from the bar to the target. one or both of the choices I will experiment with during the summer.  something  to think about are possible safe guards if somthing went wrong.

[ljd10]

parallel port pins 2-9 can be used to control stepper motors. and pins 15-25 are ground pins. If a person wired in a series limit switches that are either normally open or normaly closed. hook it (possibly to an unused 2-9) and the other end of the wire to the ground pin (15-25).--which could activate 3-5 volt relay of 110-220 capacity.
activating (a spring tension release?) when the limit switch is tripped. the tension release be used to tip the whole mirror bar straight in the sky. adjust the limit swithes so they  can not possibly stray off target in any direction without tripping the limit swithes.

[Gabriel]

Yeah that would help. It might also be possible to put the parabola high enough and also use a short enough focal length so that it would be impossible for it to reach anything that might burn.