Abstract

The work aimed to study the behavior of a prototype planted simultaneously three times with solid fertilizers, nitrogen, phosphorus and potassium, of variable rates and desired quantities. For the evaluation of the prototype, a test bench was built where helical doses and their respective direct current electric motors; three tanks for storage of fertilizers were used. Also used were: A source (12 V-DC), three power drivers (MOSFET), acquisition board and control software. The tests were performed with LabVIEW®8.6 to control the rotation of the axes, record data in maps of soil fertility and geographical location. The results showed that application values showed an error of 3:56% at the rate of 45 kg/ha and an error of 1.78% at the rate of 85 kg/ha. However, the slightest mistake was on rotation of 26 to 30 rpm because the ratio flow rates had error <1%. Therefore, the dosing speed became maximum of 35 rpm; making the variation of the theoretical flow rate from 2.6 to 93.7 kg/ha. But with low flow rate, the error was 8.3% to 4 rpm on products of  9.79 kg/ha.

Key words: Data acquisition board, flow rate, helical feeders, varying rates, power drivers.