Thanks for this detailed answer, but I lack the knowledge to get the right conclusions for my assembly:- 1 Arduino uno board- 2 TB6600,- 1 Nema 23 Gear ratio 47:1Torque setting without gearbox: 1.25Nm(177.01oz.in)maximum allowed with gearbox: 40Nm(5664oz.in)Current/phase: 2.8AResistance/phase: 0.9ohmsVoltage: 2.6VInductance: 2.5mH ± 20%(1KHz)- 1 Nema 23 - 1.26 NmRated current: 2.8A DCDC Winding Resistance (25°C): 1.2 Ω ± 10% Nominal VoltageNominal voltage: 3.36VWinding inductance: 2.3mH ± 20%

I tested with the common cathode connection (your diagram 2), but it seems that I need more power ?

Can you tell me if my choice is correct ?I hope I'm not abusing your kindness too much...Thanks so much

Proteus only works on Windows. And I'm on Mac! But while searching, I found KiCad. Not as easy to approach as Fritzing, but Opensource and more powerful. I tryThanks again for all these answers

OKThanks