Hello,

So I have a 28byj-48 (5 volts) stepper motor converted to bipolar with this guide

http://www.electronicsmayhem.com/?p=13

**1.** After converting to bipolar am I right to use 10-12v dc ?

**2.** How I can calculate the current to adjust on A4988 driver ?

Here is the 28byj-48 unipolar characteristics

```
Model ： 28BYJ-48
Rated voltage ： 5VDC
Number of Phase ： 4
Speed Variation Ratio ： 1/64
Stride Angle ： 5.625° /64
Frequency : 100Hz
DC resistance ： 50Ω±7%(25℃)
Idle In-traction Frequency : > 600Hz
Idle Out-traction Frequency : > 1000Hz
In-traction Torque >34.3mN.m(120Hz)
Self-positioning Torque >34.3mN.m
Friction torque : 600-1200 gf.cm
Pull in torque : 300 gf.cm
Insulated resistance >10MΩ(500V)
Insulated electricity power ：600VAC/1mA/1s
Insulation grade ：A
Rise in Temperature <40K(120Hz)
Noise <35dB(120Hz,No load,10cm)
```

Thank you