Month: May 2013

Irrigating Your Garden With an Op Amp

Irrigating Your Garden With an Op Amp

Instructables user diy_bloke built this op-amp controlled pump for his garden, using the classic 741 operational amplifier. He wrote a very detailed how-to including showing how to etch a PCB, as well as how to make a humidity sensor out of gypsum: The simplest form of a soil humidity sensor is made from two galvanized […]

HYREL 3D Printers

HYREL 3D Printers

Daniel Hutchinson of Alpharetta, GA, is the front man for Atlanta-based HYREL 3D, a startup launched in November through a highly successful Kickstarter campaign. The idea behind their HighlY-RELiable 3D printer design is to provide an open-platform fused-filament system that does not cost as much as “industrial” machines, but requires less assembly and maintenance time than kit-based machines.