After a recent workshop at ENSAD Limoges I have come to the conclusion that drawing machines are what people find the most interesting. Video experiments, being reliant on screens, clearly don’t grab people in the same way.
The expo at the end of the week drew lots of visitors :
I’d like to revisit the solar powered sunflower experiments from years ago and adapt them to be simple drawing machines. I want them to work independently so I am imagining that they would draw with thick bars of graphite and be powered by an overhead incandescent lamp.
Some work I’ve already done in this blog : sunflower-array and dual-solar-tracking-part-iii…and elsewhere : https://github.com/merlinmarrs/tournesol
I would like to use the classic micro metal gear motors and then create the other parts with metal that I can solder with a soldering iron (not 3D printed parts).
One thing to keep in mind is to avoid making something that just draws circles all over the place. One idea to combat this is to have the solar sunflower circuit being fed by a random voltage circuit so that it will add some randomness into the composition.
Here’s the list of components I am ordering :
74AC240 (make sure it’s the AC flavour as it must work at low voltages):
https://www.mouser.fr/ProductDetail/Texas-Instruments/CD74AC240M96?qs=YxwvVplHM%2FkSs49pJJGWDg%3D%3D
0.15F cap :
https://www.mouser.fr/ProductDetail/Panasonic/2R5TPE1500MC?qs=OE1iw1LrrPHN6IeHWYVhLw%3D%3D
diode (standard 1206)
0.47uF cap (standard 1206)
x2 2.23 V Monocrystalline Solar Cell (to get above the trigger voltage in full sunlight):
https://www.digikey.fr/en/products/detail/anysolar-ltd/KXOB25-03X4F-TR/13999191
micro gear motor (make sure it works as low as 2.9V): https://www.mouser.fr/ProductDetail/DFRobot/FIT0094?qs=lqAf%2FiVYw9h6rFbdWMR0RQ%3D%3D
voltage trigger (2.9V but you can try other values): https://www.mouser.fr/ProductDetail/Renesas-Intersil/ISL88001IH29Z-T7A?qs=dAsayXGOMrvzqg4LBGVqAg%3D%3D
N-channel MOSFET: https://www.mouser.fr/ProductDetail/Diodes-Incorporated/DMN2215UDM-7?qs=ptj1V1atRArXZWZ7Y9ryoQ%3D%3D