btw, it has 6 wire idle conntrol stepper valve, which has 2 + wires in the middle of each coil, can they be disconected?
Yes
A six wire stepper motor is a Unipolar motor, Vems controls a Bipolar motor. I have successfully run a Unipolar motor with the Bipolar driver that Vems has.
The unipolar motor is made up of four windings in two pairs......... Three wires per pair.......... common wire is the centre of a pair of widnings and would normally be supplied with 12v from a fused power source, and the unipolar driver then alternates the grounds.
You can disconnect the common 12v supply, simply turning the Unipolar motor into a Bipolar motor. Just be sure that each pair of windings are disconnected from each other as the stepper motor I had was five wire, but six pin, and the 12v was common to all. you need to end up with two independent widings for this to work correctly.
For example, a Unipolar motor would normally look like this
A 12v C
| | |
|--~~~~~--|--~~~~~--|
|<--------------------------------------Just be sure that there is no common link between all four windings|--~~~~~--|--~~~~~--|
| | |
D 12v B
And by disconnecting the common 12v centre tappings you end up with a Bipolar motor like this
A C
| |
|--~~~~~-----~~~~~--|
|--~~~~~-----~~~~~--|
| |
D B